Commit Graph

6985 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
56dde68f85 Revert "serial: 8250: 8250_omap: Fix possible interrupt storm"
This reverts commit 31fae7c8b1.

Tony writes:
	I just noticed this causes the following regression in Linux
	next when pressing a key on uart console after boot at least on
	omap3. This seems to happen on serial_port_in(port, UART_RX) in
	the quirk handling.

So let's drop this.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/YLCCJzkkB4N7LTQS@atomide.com
Fixes: 31fae7c8b1 ("serial: 8250: 8250_omap: Fix possible interrupt storm")
Reported-by: Tony Lindgren <tony@atomide.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-28 10:58:49 +02:00
Christian Gmeiner
9808f9be31 serial: 8250_pci: handle FL_NOIRQ board flag
In commit 8428413b1d ("serial: 8250_pci: Implement MSI(-X) support")
the way the irq gets allocated was changed. With that change the
handling FL_NOIRQ got lost. Restore the old behaviour.

Fixes: 8428413b1d ("serial: 8250_pci: Implement MSI(-X) support")
Cc: <stable@vger.kernel.org>
Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Link: https://lore.kernel.org/r/20210527095529.26281-1-christian.gmeiner@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-27 15:22:36 +02:00
Zheyu Ma
016002848c serial: rp2: use 'request_firmware' instead of 'request_firmware_nowait'
In 'rp2_probe', the driver registers 'rp2_uart_interrupt' then calls
'rp2_fw_cb' through 'request_firmware_nowait'. In 'rp2_fw_cb', if the
firmware don't exists, function just return without initializing ports
of 'rp2_card'. But now the interrupt handler function has been
registered, and when an interrupt comes, 'rp2_uart_interrupt' may access
those ports then causing NULL pointer dereference or other bugs.

Because the driver does some initialization work in 'rp2_fw_cb', in
order to make the driver ready to handle interrupts, 'request_firmware'
should be used instead of asynchronous 'request_firmware_nowait'.

This report reveals it:

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.19.177-gdba4159c14ef-dirty #45
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-
gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xec/0x156 lib/dump_stack.c:118
 assign_lock_key kernel/locking/lockdep.c:727 [inline]
 register_lock_class+0x14e5/0x1ba0 kernel/locking/lockdep.c:753
 __lock_acquire+0x187/0x3750 kernel/locking/lockdep.c:3303
 lock_acquire+0x124/0x340 kernel/locking/lockdep.c:3907
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x32/0x50 kernel/locking/spinlock.c:144
 spin_lock include/linux/spinlock.h:329 [inline]
 rp2_ch_interrupt drivers/tty/serial/rp2.c:466 [inline]
 rp2_asic_interrupt.isra.9+0x15d/0x990 drivers/tty/serial/rp2.c:493
 rp2_uart_interrupt+0x49/0xe0 drivers/tty/serial/rp2.c:504
 __handle_irq_event_percpu+0xfb/0x770 kernel/irq/handle.c:149
 handle_irq_event_percpu+0x79/0x150 kernel/irq/handle.c:189
 handle_irq_event+0xac/0x140 kernel/irq/handle.c:206
 handle_fasteoi_irq+0x232/0x5c0 kernel/irq/chip.c:725
 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline]
 handle_irq+0x230/0x3a0 arch/x86/kernel/irq_64.c:87
 do_IRQ+0xa7/0x1e0 arch/x86/kernel/irq.c:247
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:670
 </IRQ>
RIP: 0010:native_safe_halt+0x28/0x30 arch/x86/include/asm/irqflags.h:61
Code: 00 00 55 be 04 00 00 00 48 c7 c7 00 c2 2f 8c 48 89 e5 e8 fb 31 e7 f8
8b 05 75 af 8d 03 85 c0 7e 07 0f 00 2d 8a 61 65 00 fb f4 <5d> c3 90 90 90
90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41
RSP: 0018:ffff88806b71fcc8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffde
RAX: 0000000000000000 RBX: ffffffff8bde7e48 RCX: ffffffff88a21285
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8c2fc200
RBP: ffff88806b71fcc8 R08: fffffbfff185f840 R09: fffffbfff185f840
R10: 0000000000000001 R11: fffffbfff185f840 R12: 0000000000000002
R13: ffffffff8bea18a0 R14: 0000000000000000 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
 default_idle+0x6f/0x360 arch/x86/kernel/process.c:557
 arch_cpu_idle+0xf/0x20 arch/x86/kernel/process.c:548
 default_idle_call+0x3b/0x60 kernel/sched/idle.c:93
 cpuidle_idle_call kernel/sched/idle.c:153 [inline]
 do_idle+0x2ab/0x3c0 kernel/sched/idle.c:263
 cpu_startup_entry+0xcb/0xe0 kernel/sched/idle.c:369
 start_secondary+0x3b8/0x4e0 arch/x86/kernel/smpboot.c:271
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
PGD 8000000056d27067 P4D 8000000056d27067 PUD 56d28067 PMD 0
Oops: 0000 [#1] PREEMPT SMP KASAN PTI
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.19.177-gdba4159c14ef-dirty #45
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-
gc9ba5276e321-prebuilt.qemu.org 04/01/2014
RIP: 0010:readl arch/x86/include/asm/io.h:59 [inline]
RIP: 0010:rp2_ch_interrupt drivers/tty/serial/rp2.c:472 [inline]
RIP: 0010:rp2_asic_interrupt.isra.9+0x181/0x990 drivers/tty/serial/rp2.c:
493
Code: df e8 43 5d c2 05 48 8d 83 e8 01 00 00 48 89 85 60 ff ff ff 48 c1 e8
03 42 80 3c 30 00 0f 85 aa 07 00 00 48 8b 83 e8 01 00 00 <8b> 40 10 89 c1
89 85 68 ff ff ff 48 8b 83 e8 01 00 00 89 48 10 83
RSP: 0018:ffff88806c287cd0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff88806ade6820 RCX: ffffffff814300b1
RDX: 1ffff1100d5bcd06 RSI: 0000000000000004 RDI: ffff88806ade6820
RBP: ffff88806c287db8 R08: ffffed100d5bcd05 R09: ffffed100d5bcd05
R10: 0000000000000001 R11: ffffed100d5bcd04 R12: ffffc90001e00000
R13: ffff888069654e10 R14: dffffc0000000000 R15: ffff888069654df0
FS:  0000000000000000(0000) GS:ffff88806c280000(0000) knlGS:
0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000006892c000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rp2_uart_interrupt+0x49/0xe0 drivers/tty/serial/rp2.c:504
 __handle_irq_event_percpu+0xfb/0x770 kernel/irq/handle.c:149
 handle_irq_event_percpu+0x79/0x150 kernel/irq/handle.c:189
 handle_irq_event+0xac/0x140 kernel/irq/handle.c:206
 handle_fasteoi_irq+0x232/0x5c0 kernel/irq/chip.c:725
 generic_handle_irq_desc include/linux/irqdesc.h:155 [inline]
 handle_irq+0x230/0x3a0 arch/x86/kernel/irq_64.c:87
 do_IRQ+0xa7/0x1e0 arch/x86/kernel/irq.c:247
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:670
 </IRQ>
RIP: 0010:native_safe_halt+0x28/0x30 arch/x86/include/asm/irqflags.h:61
Code: 00 00 55 be 04 00 00 00 48 c7 c7 00 c2 2f 8c 48 89 e5 e8 fb 31 e7
f8 8b 05 75 af 8d 03 85 c0 7e 07 0f 00 2d 8a 61 65 00 fb f4 <5d> c3 90
90 90 90 90 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41
RSP: 0018:ffff88806b71fcc8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffde
RAX: 0000000000000000 RBX: ffffffff8bde7e48 RCX: ffffffff88a21285
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff8c2fc200
RBP: ffff88806b71fcc8 R08: fffffbfff185f840 R09: fffffbfff185f840
R10: 0000000000000001 R11: fffffbfff185f840 R12: 0000000000000002
R13: ffffffff8bea18a0 R14: 0000000000000000 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
 default_idle+0x6f/0x360 arch/x86/kernel/process.c:557
 arch_cpu_idle+0xf/0x20 arch/x86/kernel/process.c:548
 default_idle_call+0x3b/0x60 kernel/sched/idle.c:93
 cpuidle_idle_call kernel/sched/idle.c:153 [inline]
 do_idle+0x2ab/0x3c0 kernel/sched/idle.c:263
 cpu_startup_entry+0xcb/0xe0 kernel/sched/idle.c:369
 start_secondary+0x3b8/0x4e0 arch/x86/kernel/smpboot.c:271
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
Modules linked in:
Dumping ftrace buffer:
   (ftrace buffer empty)
CR2: 0000000000000010
---[ end trace 11804dbb55cb1a64 ]---
RIP: 0010:readl arch/x86/include/asm/io.h:59 [inline]
RIP: 0010:rp2_ch_interrupt drivers/tty/serial/rp2.c:472 [inline]
RIP: 0010:rp2_asic_interrupt.isra.9+0x181/0x990 drivers/tty/serial/rp2.c:
493
Code: df e8 43 5d c2 05 48 8d 83 e8 01 00 00 48 89 85 60 ff ff ff 48 c1
e8 03 42 80 3c 30 00 0f 85 aa 07 00 00 48 8b 83 e8 01 00 00 <8b> 40 10 89
c1 89 85 68 ff ff ff 48 8b 83 e8 01 00 00 89 48 10 83
RSP: 0018:ffff88806c287cd0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff88806ade6820 RCX: ffffffff814300b1
RDX: 1ffff1100d5bcd06 RSI: 0000000000000004 RDI: ffff88806ade6820
RBP: ffff88806c287db8 R08: ffffed100d5bcd05 R09: ffffed100d5bcd05
R10: 0000000000000001 R11: ffffed100d5bcd04 R12: ffffc90001e00000
R13: ffff888069654e10 R14: dffffc0000000000 R15: ffff888069654df0
FS:  0000000000000000(0000) GS:ffff88806c280000(0000) knlGS:
0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000010 CR3: 000000006892c000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Reported-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Link: https://lore.kernel.org/r/1621577323-1541-1-git-send-email-zheyuma97@gmail.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-21 20:34:02 +02:00
Randy Wright
e0e2420879 serial: 8250_pci: Add support for new HPE serial device
Add support for new HPE serial device.  It is MSI enabled,
but otherwise similar to legacy HP server serial devices.

Tested-by: Jerry Hoemann <jerry.hoemann@hpe.com>
Signed-off-by: Randy Wright <rwright@hpe.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/1621009614-28836-1-git-send-email-rwright@hpe.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20 17:17:16 +02:00
Vignesh Raghavendra
31fae7c8b1 serial: 8250: 8250_omap: Fix possible interrupt storm
It is possible that RX TIMEOUT is signalled after RX FIFO has been
drained, in which case a dummy read of RX FIFO is required to clear RX
TIMEOUT condition. Otherwise, RX TIMEOUT condition is not cleared
leading to an interrupt storm

Cc: stable@vger.kernel.org
Reported-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>
Link: https://lore.kernel.org/r/20210511151955.28071-1-vigneshr@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20 17:16:55 +02:00
Andrew Jeffery
1f06f5713f serial: 8250: Use BIT(x) for UART_{CAP,BUG}_*
BIT(x) improves readability and safety with respect to shifts.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/20210520021334.497341-3-andrew@aj.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20 17:14:50 +02:00
Andrew Jeffery
df8f2be2fd serial: 8250: Add UART_BUG_TXRACE workaround for Aspeed VUART
Aspeed Virtual UARTs directly bridge e.g. the system console UART on the
LPC bus to the UART interface on the BMC's internal APB. As such there's
no RS-232 signalling involved - the UART interfaces on each bus are
directly connected as the producers and consumers of the one set of
FIFOs.

The APB in the AST2600 generally runs at 100MHz while the LPC bus peaks
at 33MHz. The difference in clock speeds exposes a race in the VUART
design where a Tx data burst on the APB interface can result in a byte
lost on the LPC interface. The symptom is LSR[DR] remains clear on the
LPC interface despite data being present in its Rx FIFO, while LSR[THRE]
remains clear on the APB interface as the host has not consumed the data
the BMC has transmitted. In this state, the UART has stalled and no
further data can be transmitted without manual intervention (e.g.
resetting the FIFOs, resulting in loss of data).

The recommended work-around is to insert a read cycle on the APB
interface between writes to THR.

Cc: ChiaWei Wang <chiawei_wang@aspeedtech.com>
Tested-by: ChiaWei Wang <chiawei_wang@aspeedtech.com>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210520021334.497341-2-andrew@aj.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-20 17:14:46 +02:00
Maximilian Luz
3c35d2a960 serial: 8250_dw: Add device HID for new AMD UART controller
Add device HID AMDI0022 to the AMD UART controller driver match table
and create a platform device for it. This controller can be found on
Microsoft Surface Laptop 4 devices and seems similar enough that we can
just copy the existing AMDI0020 entries.

Cc: <stable@vger.kernel.org> # 5.10+
Tested-by: Sachi King <nakato@nakato.io>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # for 8250_dw part
Signed-off-by: Maximilian Luz <luzmaximilian@gmail.com>
Link: https://lore.kernel.org/r/20210512210413.1982933-1-luzmaximilian@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13 17:08:42 +02:00
Geert Uytterhoeven
2ea2e019c1 serial: sh-sci: Fix off-by-one error in FIFO threshold register setting
The Receive FIFO Data Count Trigger field (RTRG[6:0]) in the Receive
FIFO Data Count Trigger Register (HSRTRGR) of HSCIF can only hold values
ranging from 0-127.  As the FIFO size is equal to 128 on HSCIF, the user
can write an out-of-range value, touching reserved bits.

Fix this by limiting the trigger value to the FIFO size minus one.
Reverse the order of the checks, to avoid rx_trig becoming zero if the
FIFO size is one.

Note that this change has no impact on other SCIF variants, as their
maximum supported trigger value is lower than the FIFO size anyway, and
the code below takes care of enforcing these limits.

Fixes: a380ed461f ("serial: sh-sci: implement FIFO threshold register setting")
Reported-by: Linh Phung <linh.phung.jy@renesas.com>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/5eff320aef92ffb33d00e57979fd3603bbb4a70f.1620648218.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13 17:08:29 +02:00
Ondrej Mosnacek
5e722b217a serial: core: fix suspicious security_locked_down() call
The commit that added this check did so in a very strange way - first
security_locked_down() is called, its value stored into retval, and if
it's nonzero, then an additional check is made for (change_irq ||
change_port), and if this is true, the function returns. However, if
the goto exit branch is not taken, the code keeps the retval value and
continues executing the function. Then, depending on whether
uport->ops->verify_port is set, the retval value may or may not be reset
to zero and eventually the error value from security_locked_down() may
abort the function a few lines below.

I will go out on a limb and assume that this isn't the intended behavior
and that an error value from security_locked_down() was supposed to
abort the function only in case (change_irq || change_port) is true.

Note that security_locked_down() should be called last in any series of
checks, since the SELinux implementation of this hook will do a check
against the policy and generate an audit record in case of denial. If
the operation was to carry on after calling security_locked_down(), then
the SELinux denial record would be bogus.

See commit 59438b4647 ("security,lockdown,selinux: implement SELinux
lockdown") for how SELinux implements this hook.

Fixes: 794edf30ee ("lockdown: Lock down TIOCSSERIAL")
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210507115719.140799-1-omosnace@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13 17:08:04 +02:00
Colin Ian King
3ddb4ce1e6 serial: tegra: Fix a mask operation that is always true
Currently the expression lsr | UART_LSR_TEMT is always true and
this seems suspect. I believe the intent was to mask lsr with UART_LSR_TEMT
to check that bit, so the expression should be using the & operator
instead. Fix this.

Fixes: b9c2470fb1 ("serial: tegra: flush the RX fifo on frame error")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210426105514.23268-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-13 17:07:43 +02:00
Masahiro Yamada
9009b45581 .gitignore: prefix local generated files with a slash
The pattern prefixed with '/' matches files in the same directory,
but not ones in sub-directories.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Andra Paraschiv <andraprs@amazon.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Gabriel Krisman Bertazi <krisman@collabora.com>
2021-05-02 00:43:35 +09:00
Linus Torvalds
5469f160e6 Power management updates for 5.13-rc1
- Add idle states table for IceLake-D to the intel_idle driver and
    update IceLake-X C6 data in it (Artem Bityutskiy).
 
  - Fix the C7 idle state on Tegra114 in the tegra cpuidle driver and
    drop the unused do_idle() firmware call from it (Dmitry Osipenko).
 
  - Fix cpuidle-qcom-spm Kconfig entry (He Ying).
 
  - Fix handling of possible negative tick_nohz_get_next_hrtimer()
    return values of in cpuidle governors (Rafael Wysocki).
 
  - Add support for frequency-invariance to the ACPI CPPC cpufreq
    driver and update the frequency-invariance engine (FIE) to use it
    as needed (Viresh Kumar).
 
  - Simplify the default delay_us setting in the ACPI CPPC cpufreq
    driver (Tom Saeger).
 
  - Clean up frequency-related computations in the intel_pstate
    cpufreq driver (Rafael Wysocki).
 
  - Fix TBG parent setting for load levels in the armada-37xx
    cpufreq driver and drop the CPU PM clock .set_parent method for
    armada-37xx (Marek Behún).
 
  - Fix multiple issues in the armada-37xx cpufreq driver (Pali Rohár).
 
  - Fix handling of dev_pm_opp_of_cpumask_add_table() return values
    in cpufreq-dt to take the -EPROBE_DEFER one into acconut as
    appropriate (Quanyang Wang).
 
  - Fix format string in ia64-acpi-cpufreq (Sergei Trofimovich).
 
  - Drop the unused for_each_policy() macro from cpufreq (Shaokun
    Zhang).
 
  - Simplify computations in the schedutil cpufreq governor to avoid
    unnecessary overhead (Yue Hu).
 
  - Fix typos in the s5pv210 cpufreq driver (Bhaskar Chowdhury).
 
  - Fix cpufreq documentation links in Kconfig (Alexander Monakov).
 
  - Fix PCI device power state handling in pci_enable_device_flags()
    to avoid issuse in some cases when the device depends on an ACPI
    power resource (Rafael Wysocki).
 
  - Add missing documentation of pm_runtime_resume_and_get() (Alan
    Stern).
 
  - Add missing static inline stub for pm_runtime_has_no_callbacks()
    to pm_runtime.h and drop the unused try_to_freeze_nowarn()
    definition (YueHaibing).
 
  - Drop duplicate struct device declaration from pm.h and fix a
    structure type declaration in intel_rapl.h (Wan Jiabing).
 
  - Use dev_set_name() instead of an open-coded equivalent of it in
    the wakeup sources code and drop a redundant local variable
    initialization from it (Andy Shevchenko, Colin Ian King).
 
  - Use crc32 instead of md5 for e820 memory map integrity check
    during resume from hibernation on x86 (Chris von Recklinghausen).
 
  - Fix typos in comments in the system-wide and hibernation support
    code (Lu Jialin).
 
  - Modify the generic power domains (genpd) code to avoid resuming
    devices in the "prepare" phase of system-wide suspend and
    hibernation (Ulf Hansson).
 
  - Add Hygon Fam18h RAPL support to the intel_rapl power capping
    driver (Pu Wen).
 
  - Add MAINTAINERS entry for the dynamic thermal power management
    (DTPM) code (Daniel Lezcano).
 
  - Add devm variants of operating performance points (OPP) API
    functions and switch over some users of the OPP framework to
    the new resource-managed API (Yangtao Li and Dmitry Osipenko).
 
  - Update devfreq core:
 
    * Register devfreq devices as cooling devices on demand (Daniel
      Lezcano).
 
    * Add missing unlock opeation in devfreq_add_device() (Lukasz
      Luba).
 
    * Use the next frequency as resume_freq instead of the previous
      frequency when using the opp-suspend property (Dong Aisheng).
 
    * Check get_dev_status in devfreq_update_stats() (Dong Aisheng).
 
    * Fix set_freq path for the userspace governor in Kconfig (Dong
      Aisheng).
 
    * Remove invalid description of get_target_freq() (Dong Aisheng).
 
  - Update devfreq drivers:
 
    * imx8m-ddrc: Remove imx8m_ddrc_get_dev_status() and unneeded
      of_match_ptr() (Dong Aisheng, Fabio Estevam).
 
    * rk3399_dmc: dt-bindings: Add rockchip,pmu phandle and drop
      references to undefined symbols (Enric Balletbo i Serra, Gaël
      PORTAY).
 
    * rk3399_dmc: Use dev_err_probe() to simplify the code (Krzysztof
      Kozlowski).
 
    * imx-bus: Remove unneeded of_match_ptr() (Fabio Estevam).
 
  - Fix kernel-doc warnings in three places (Pierre-Louis Bossart).
 
  - Fix typo in the pm-graph utility code (Ricardo Ribalda).
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Merge tag 'pm-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These add some new hardware support (for example, IceLake-D idle
  states in intel_idle), fix some issues (for example, the handling of
  negative "sleep length" values in cpuidle governors), add new
  functionality to the existing drivers (for example, scale-invariance
  support in the ACPI CPPC cpufreq driver) and clean up code all over.

  Specifics:

   - Add idle states table for IceLake-D to the intel_idle driver and
     update IceLake-X C6 data in it (Artem Bityutskiy).

   - Fix the C7 idle state on Tegra114 in the tegra cpuidle driver and
     drop the unused do_idle() firmware call from it (Dmitry Osipenko).

   - Fix cpuidle-qcom-spm Kconfig entry (He Ying).

   - Fix handling of possible negative tick_nohz_get_next_hrtimer()
     return values of in cpuidle governors (Rafael Wysocki).

   - Add support for frequency-invariance to the ACPI CPPC cpufreq
     driver and update the frequency-invariance engine (FIE) to use it
     as needed (Viresh Kumar).

   - Simplify the default delay_us setting in the ACPI CPPC cpufreq
     driver (Tom Saeger).

   - Clean up frequency-related computations in the intel_pstate cpufreq
     driver (Rafael Wysocki).

   - Fix TBG parent setting for load levels in the armada-37xx cpufreq
     driver and drop the CPU PM clock .set_parent method for armada-37xx
     (Marek Behún).

   - Fix multiple issues in the armada-37xx cpufreq driver (Pali Rohár).

   - Fix handling of dev_pm_opp_of_cpumask_add_table() return values in
     cpufreq-dt to take the -EPROBE_DEFER one into acconut as
     appropriate (Quanyang Wang).

   - Fix format string in ia64-acpi-cpufreq (Sergei Trofimovich).

   - Drop the unused for_each_policy() macro from cpufreq (Shaokun
     Zhang).

   - Simplify computations in the schedutil cpufreq governor to avoid
     unnecessary overhead (Yue Hu).

   - Fix typos in the s5pv210 cpufreq driver (Bhaskar Chowdhury).

   - Fix cpufreq documentation links in Kconfig (Alexander Monakov).

   - Fix PCI device power state handling in pci_enable_device_flags() to
     avoid issuse in some cases when the device depends on an ACPI power
     resource (Rafael Wysocki).

   - Add missing documentation of pm_runtime_resume_and_get() (Alan
     Stern).

   - Add missing static inline stub for pm_runtime_has_no_callbacks() to
     pm_runtime.h and drop the unused try_to_freeze_nowarn() definition
     (YueHaibing).

   - Drop duplicate struct device declaration from pm.h and fix a
     structure type declaration in intel_rapl.h (Wan Jiabing).

   - Use dev_set_name() instead of an open-coded equivalent of it in the
     wakeup sources code and drop a redundant local variable
     initialization from it (Andy Shevchenko, Colin Ian King).

   - Use crc32 instead of md5 for e820 memory map integrity check during
     resume from hibernation on x86 (Chris von Recklinghausen).

   - Fix typos in comments in the system-wide and hibernation support
     code (Lu Jialin).

   - Modify the generic power domains (genpd) code to avoid resuming
     devices in the "prepare" phase of system-wide suspend and
     hibernation (Ulf Hansson).

   - Add Hygon Fam18h RAPL support to the intel_rapl power capping
     driver (Pu Wen).

   - Add MAINTAINERS entry for the dynamic thermal power management
     (DTPM) code (Daniel Lezcano).

   - Add devm variants of operating performance points (OPP) API
     functions and switch over some users of the OPP framework to the
     new resource-managed API (Yangtao Li and Dmitry Osipenko).

   - Update devfreq core:

      * Register devfreq devices as cooling devices on demand (Daniel
        Lezcano).

      * Add missing unlock opeation in devfreq_add_device() (Lukasz
        Luba).

      * Use the next frequency as resume_freq instead of the previous
        frequency when using the opp-suspend property (Dong Aisheng).

      * Check get_dev_status in devfreq_update_stats() (Dong Aisheng).

      * Fix set_freq path for the userspace governor in Kconfig (Dong
        Aisheng).

      * Remove invalid description of get_target_freq() (Dong Aisheng).

   - Update devfreq drivers:

      * imx8m-ddrc: Remove imx8m_ddrc_get_dev_status() and unneeded
        of_match_ptr() (Dong Aisheng, Fabio Estevam).

      * rk3399_dmc: dt-bindings: Add rockchip,pmu phandle and drop
        references to undefined symbols (Enric Balletbo i Serra, Gaël
        PORTAY).

      * rk3399_dmc: Use dev_err_probe() to simplify the code (Krzysztof
        Kozlowski).

      * imx-bus: Remove unneeded of_match_ptr() (Fabio Estevam).

   - Fix kernel-doc warnings in three places (Pierre-Louis Bossart).

   - Fix typo in the pm-graph utility code (Ricardo Ribalda)"

* tag 'pm-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (74 commits)
  PM: wakeup: remove redundant assignment to variable retval
  PM: hibernate: x86: Use crc32 instead of md5 for hibernation e820 integrity check
  cpufreq: Kconfig: fix documentation links
  PM: wakeup: use dev_set_name() directly
  PM: runtime: Add documentation for pm_runtime_resume_and_get()
  cpufreq: intel_pstate: Simplify intel_pstate_update_perf_limits()
  cpufreq: armada-37xx: Fix module unloading
  cpufreq: armada-37xx: Remove cur_frequency variable
  cpufreq: armada-37xx: Fix determining base CPU frequency
  cpufreq: armada-37xx: Fix driver cleanup when registration failed
  clk: mvebu: armada-37xx-periph: Fix workaround for switching from L1 to L0
  clk: mvebu: armada-37xx-periph: Fix switching CPU freq from 250 Mhz to 1 GHz
  cpufreq: armada-37xx: Fix the AVS value for load L1
  clk: mvebu: armada-37xx-periph: remove .set_parent method for CPU PM clock
  cpufreq: armada-37xx: Fix setting TBG parent for load levels
  cpuidle: Fix ARM_QCOM_SPM_CPUIDLE configuration
  cpuidle: tegra: Remove do_idle firmware call
  cpuidle: tegra: Fix C7 idling state on Tegra114
  PM: sleep: fix typos in comments
  cpufreq: Remove unused for_each_policy macro
  ...
2021-04-26 15:10:25 -07:00
Linus Torvalds
37f00ab4a0 ARM: SoC drivers for v5.13
Updates for SoC specific drivers include a few subsystems that
 have their own maintainers but send them through the soc tree:
 
 TEE/OP-TEE:
  -  Add tracepoints around calls to secure world
 
 Memory controller drivers:
  - Minor fixes for Renesas, Exynos, Mediatek and Tegra platforms
  - Add debug statistics to Tegra20 memory controller
  - Update Tegra bindings and convert to dtschema
 
 ARM SCMI Firmware:
  - Support for modular SCMI protocols and vendor specific extensions
  - New SCMI IIO driver
  - Per-cpu DVFS
 
 The other driver changes are all from the platform maintainers
 directly and reflect the drivers that don't fit into any other
 subsystem as well as treewide changes for a particular platform.
 
 SoCFPGA:
  - Various cleanups contributed by Krzysztof Kozlowski
 
 Mediatek:
  - add MT8183 support to mutex driver
  - MMSYS: use per SoC array to describe the possible routing
  - add MMSYS support for MT8183 and MT8167
  - add support for PMIC wrapper with integrated arbiter
  - add support for MT8192/MT6873
 
 Tegra:
  - Bug fixes to PMC and clock drivers
 
 NXP/i.MX:
  - Update SCU power domain driver to keep console domain power on.
  - Add missing ADC1 power domain to SCU power domain driver.
  - Update comments for single global power domain in SCU power domain
    driver.
  - Add i.MX51/i.MX53 unique id support to i.MX SoC driver.
 
 NXP/FSL SoC driver updates for v5.13
  - Add ACPI support for RCPM driver
  - Use generic io{read,write} for QE drivers after performance optimized
    for PowerPC
  - Fix QBMAN probe to cleanup HW states correctly for kexec
  - Various cleanup and style fix for QBMAN/QE/GUTS drivers
 
 OMAP:
  - Preparation to use devicetree for genpd
  - ti-sysc needs iorange check improved when the interconnect target module
    has no control registers listed
  - ti-sysc needs to probe l4_wkup and l4_cfg interconnects first to avoid
    issues with missing resources and unnecessary deferred probe
  - ti-sysc debug option can now detect more devices
  - ti-sysc now warns if an old incomplete devicetree data is found as we
    now rely on it being complete for am3 and 4
  - soc init code needs to check for prcm and prm nodes for omap4/5 and dra7
  - omap-prm driver needs to enable autoidle retention support for omap4
  - omap5 clocks are missing gpmc and ocmc clock registers
  - pci-dra7xx now needs to use builtin_platform_driver instead of using
    builtin_platform_driver_probe for deferred probe to work
 
 Raspberry Pi:
  - Fix-up all RPi firmware drivers so as for unbind to happen in an
    orderly fashion
  - Support for RPi's PoE hat PWM bus
 
 Qualcomm
  - Improved detection for SCM calling conventions
  - Support for OEM specific wifi firmware path
  - Added drivers for SC7280/SM8350: RPMH, LLCC< AOSS QMP
 
 Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Merge tag 'arm-drivers-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc

Pull ARM SoC driver updates from Arnd Bergmann:
 "Updates for SoC specific drivers include a few subsystems that have
  their own maintainers but send them through the soc tree:

  TEE/OP-TEE:
   - Add tracepoints around calls to secure world

  Memory controller drivers:
   - Minor fixes for Renesas, Exynos, Mediatek and Tegra platforms
   - Add debug statistics to Tegra20 memory controller
   - Update Tegra bindings and convert to dtschema

  ARM SCMI Firmware:
   - Support for modular SCMI protocols and vendor specific extensions
   - New SCMI IIO driver
   - Per-cpu DVFS

  The other driver changes are all from the platform maintainers
  directly and reflect the drivers that don't fit into any other
  subsystem as well as treewide changes for a particular platform.

  SoCFPGA:
   - Various cleanups contributed by Krzysztof Kozlowski

  Mediatek:
   - add MT8183 support to mutex driver
   - MMSYS: use per SoC array to describe the possible routing
   - add MMSYS support for MT8183 and MT8167
   - add support for PMIC wrapper with integrated arbiter
   - add support for MT8192/MT6873

  Tegra:
   - Bug fixes to PMC and clock drivers

  NXP/i.MX:
   - Update SCU power domain driver to keep console domain power on.
   - Add missing ADC1 power domain to SCU power domain driver.
   - Update comments for single global power domain in SCU power domain
     driver.
   - Add i.MX51/i.MX53 unique id support to i.MX SoC driver.

  NXP/FSL SoC driver updates for v5.13
   - Add ACPI support for RCPM driver
   - Use generic io{read,write} for QE drivers after performance
     optimized for PowerPC
   - Fix QBMAN probe to cleanup HW states correctly for kexec
   - Various cleanup and style fix for QBMAN/QE/GUTS drivers

  OMAP:
   - Preparation to use devicetree for genpd
   - ti-sysc needs iorange check improved when the interconnect target
     module has no control registers listed
   - ti-sysc needs to probe l4_wkup and l4_cfg interconnects first to
     avoid issues with missing resources and unnecessary deferred probe
   - ti-sysc debug option can now detect more devices
   - ti-sysc now warns if an old incomplete devicetree data is found as
     we now rely on it being complete for am3 and 4
   - soc init code needs to check for prcm and prm nodes for omap4/5 and
     dra7
   - omap-prm driver needs to enable autoidle retention support for
     omap4
   - omap5 clocks are missing gpmc and ocmc clock registers
   - pci-dra7xx now needs to use builtin_platform_driver instead of
     using builtin_platform_driver_probe for deferred probe to work

  Raspberry Pi:
   - Fix-up all RPi firmware drivers so as for unbind to happen in an
     orderly fashion
   - Support for RPi's PoE hat PWM bus

  Qualcomm
   - Improved detection for SCM calling conventions
   - Support for OEM specific wifi firmware path
   - Added drivers for SC7280/SM8350: RPMH, LLCC< AOSS QMP"

* tag 'arm-drivers-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (165 commits)
  soc: aspeed: fix a ternary sign expansion bug
  memory: mtk-smi: Add device-link between smi-larb and smi-common
  memory: samsung: exynos5422-dmc: handle clk_set_parent() failure
  memory: renesas-rpc-if: fix possible NULL pointer dereference of resource
  clk: socfpga: fix iomem pointer cast on 64-bit
  soc: aspeed: Adapt to new LPC device tree layout
  pinctrl: aspeed-g5: Adapt to new LPC device tree layout
  ipmi: kcs: aspeed: Adapt to new LPC DTS layout
  ARM: dts: Remove LPC BMC and Host partitions
  dt-bindings: aspeed-lpc: Remove LPC partitioning
  soc: fsl: enable acpi support in RCPM driver
  soc: qcom: mdt_loader: Detect truncated read of segments
  soc: qcom: mdt_loader: Validate that p_filesz < p_memsz
  soc: qcom: pdr: Fix error return code in pdr_register_listener
  firmware: qcom_scm: Fix kernel-doc function names to match
  firmware: qcom_scm: Suppress sysfs bind attributes
  firmware: qcom_scm: Workaround lack of "is available" call on SC7180
  firmware: qcom_scm: Reduce locking section for __get_convention()
  firmware: qcom_scm: Make __qcom_scm_is_call_available() return bool
  Revert "soc: fsl: qe: introduce qe_io{read,write}* wrappers"
  ...
2021-04-26 12:11:52 -07:00
Johan Hovold
8720037d55 serial: extend compile-test coverage
Allow more drivers to be compile tested more easily, for example, when
doing subsystem-wide changes.

Verified on X86_64 as well as arm, powerpc and m68k with minimal configs
in order to catch missing implicit build dependencies (e.g. MAILBOX for
SERIAL_TEGRA_TCU).

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210422080211.29326-1-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 13:12:13 +02:00
Fabrice Gasnier
2aa1bbb21f serial: stm32: add FIFO threshold configuration
Add the support for two optional DT properties, to configure RX and TX
FIFO thresholds:
- rx-threshold
- tx-threshold
This replaces hard-coded 8 bytes threshold. Keep 8 as the default value if
not specified, for backward compatibility.

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@foss.st.com>
Signed-off-by: Erwan Le Ray <erwan.leray@foss.st.com>

Changes in v2:
Change added properties naming as proposed by Rob Herring.
Link: https://lore.kernel.org/r/20210413174015.23011-5-erwan.leray@foss.st.com

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:11:25 +02:00
Johan Hovold
348fbd6170 serial: xilinx_uartps: drop low-latency workaround
Commit c8dbdc842d ("serial: xuartps: Rewrite the interrupt handling
logic") reworked the driver interrupt processing but also, without
comment, added an unnecessary workaround for the infamous low_latency
behaviour of tty_flip_buffer_push() which had been removed years
before.

Specifically, since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-27-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00
Johan Hovold
4e11dbb518 serial: vt8500: drop low-latency workaround
Commit de49df5836 ("tty: serial: vt8500: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Cc: Tony Prisk <linux@prisktech.co.nz>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-26-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00
Johan Hovold
177765b350 serial: timbuart: drop low-latency workaround
The timbuart driver has always carried a workaround for the infamous
low_latency behaviour of tty_flip_buffer_push() which required not
holding the port lock when the low_latency flag was set.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-25-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00
Johan Hovold
3f6dbe6212 serial: sunsu: drop low-latency workaround
The sunsu driver has been carrying a workaround for the infamous
low_latency behaviour of tty_flip_buffer_push() by dropping and
reacquiring the port lock in the interrupt handler since 2004.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-24-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00
Johan Hovold
0f8a732822 serial: sifive: drop low-latency workaround
The sifive driver has always carried an unnecessary workaround for the
infamous low_latency behaviour of tty_flip_buffer_push() which had been
removed years before the driver was added by commit 45c054d081 ("tty:
serial: add driver for the SiFive UART").

Specifically, since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-23-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00
Johan Hovold
38616c225e serial: txx9: drop low-latency workaround
Commit f5ee56cc18 ("[PATCH] txx9 serial update") worked around the
infamous low_latency behaviour of tty_flip_buffer_push() by simply
dropping and reacquiring the port lock in the interrupt handler.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-22-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00
Johan Hovold
f306226ee5 serial: sa1100: drop low-latency workaround
Commit 53e0e6706c ("tty: serial: sa1100: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-21-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00
Johan Hovold
e1bd674499 serial: rp2: drop low-latency workaround
Commit de7053c771 ("tty: serial: rp2: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Cc: Kevin Cernekee <cernekee@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-20-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00
Johan Hovold
2225ee132c serial: rda: drop low-latency workaround
The rda driver has always carried an unnecessary workaround for the
infamous low_latency behaviour of tty_flip_buffer_push(), which had
been removed years before the driver was added by commit c10b13325c
("tty: serial: Add RDA8810PL UART driver").

Specifically, since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-19-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00
Johan Hovold
493a275c04 serial: owl: drop low-latency workaround
The owl driver has always carried an unnecessary workaround for the
infamous low_latency behaviour of tty_flip_buffer_push(), which had
been removed years before the driver was added by commit fc60a8b675
("tty: serial: owl: Implement console driver").

Specifically, since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-18-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
c0a6c9f79e serial: msm_serial: drop low-latency workaround
Commit f77232dab2 ("tty: serial: msm: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-17-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
6e560913aa serial: mpc52xx_uart: drop low-latency workaround
Commit fbe543b412 ("Fix a potential issue in mpc52xx uart driver")
worked around the infamous low_latency behaviour of
tty_flip_buffer_push() by simply dropping and reacquiring the port lock
in the interrupt handler.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-16-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
b8555963ca serial: meson: drop low-latency workaround
The meson driver has always carried an unnecessary workaround for the
infamous low_latency behaviour of tty_flip_buffer_push(), which had
already been removed by the time the driver was added by commit
ff7693d079 ("ARM: meson: serial: add MesonX SoC on-chip uart driver").

Specifically, since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-15-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
5d148754da serial: mcf: drop low-latency workaround
Commit 5275ad70fe ("tty: serial: mcf: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-14-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
46a2675e8f serial: lpc32xx_hs: drop low-latency workaround
Commit ec12851090 ("tty: serial: lpc32xx_hs: drop uart_port->lock
before calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-13-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
4eec66e4b2 serial: icom: drop low-latency workaround
Commit 5faf75d7fe ("tty: serial: icom: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-12-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
acf4843631 serial: bcm63xx: drop low-latency workaround
Commit b4d499241c ("tty: serial: bcm63xx: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-11-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
983fe58ad7 serial: atmel_serial: drop low-latency workaround
Commit 1ecc26bd27 ("atmel_serial: split the interrupt handler") worked
around the infamous low_latency behaviour of tty_flip_buffer_push() by
dropping and reacquiring the port lock in the tasklet callback.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Cc: Richard Genoud <richard.genoud@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-10-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
e9af7e363a serial: arc_uart: drop low-latency workaround
Commit 3fa1200851 ("tty: serial: arc: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-9-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
80d43febac serial: ar933x: drop low-latency workaround
Commit b16c8e3eed ("tty: serial: ar933x: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-8-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
d0aa2820b9 serial: apbuart: drop low-latency workaround
Commit 78d34d75c8 ("tty: serial: apbuart: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-7-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:25 +02:00
Johan Hovold
02d5364007 serial: amba-pl011: drop low-latency workaround
Commit ead76f329f ("ARM: 6763/1: pl011: add optional RX DMA to PL011
v2") added RX DMA support and also reproduced the workaround for the
infamous low_latency behaviour of tty_flip_buffer_push() by dropping and
reacquiring the port lock during receive processing.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Note that the port lock is also dropped in the PIO path
(see pl011_rx_chars), but it is not clear whether this is still needed
by the DMA code added by the aforementioned commit.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Russell King <linux@armlinux.org.uk>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-6-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:24 +02:00
Johan Hovold
173d37fc59 serial: amba-pl010: drop low-latency workaround
Commit 2389b27216 ("[ARM] 4417/1: Serial: Fix AMBA drivers locking")
worked around the infamous low_latency behaviour of
tty_flip_buffer_push() by simply dropping and reacquiring the port lock
in the interrupt handler.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:24 +02:00
Johan Hovold
d26595d188 serial: altera_uart: drop low-latency workaround
Commit dd085ed8ef ("tty: serial: altera: drop uart_port->lock before
calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Cc: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:24 +02:00
Johan Hovold
f22dd43fc1 serial: altera_jtaguart: drop low-latency workaround
Commit 53dd0ba7a6 ("tty: serial: altera_jtag: drop uart_port->lock
before calling tty_flip_buffer_push()") claimed to address a locking
issue but only provided a dubious lockdep splat from an unrelated
driver, which in the end turned out to be due a broken local change
carried by the author.

Unfortunately these patches were merged before the issue had been
analysed properly so the commit messages makes no sense whatsoever.

The real issue was first seen on RT which at the time effectively always
set the low_latency flag for all serial drivers by patching
tty_flip_buffer_push(). This in turn revealed that many drivers did not
handle the infamous low_latency behaviour which meant that data was
pushed immediately to the line discipline instead of being deferred to a
work queue.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks
around.

Link: https://lore.kernel.org/linux-serial/cover.1376923198.git.viresh.kumar@linaro.org/
Cc: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:24 +02:00
Johan Hovold
02ca144fa4 tty: mxser: drop low-latency workaround
Commit 67d2bc58af ("Char: mxser_new, fix recursive locking") worked
around the infamous low_latency behaviour of tty_flip_buffer_push() by
simply dropping and reacquiring the port lock in the interrupt handler.

Since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Link: https://lore.kernel.org/lkml/3018694794025219@wsc.cz/T/#m06b04c640a7b6f41afb3d34a4cf29b1df4935d3a
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:24 +02:00
Dario Binacchi
e2a5e8448e serial: omap: fix rs485 half-duplex filtering
Data received during half-duplex transmission must be filtered.
If the target device responds quickly, emptying the FIFO at the end of
the transmission can erase not only the echo characters but also part of
the response message.
By keeping the receive interrupt enabled even during transmission, it
allows you to filter each echo character and only in a number equal to
those transmitted.
The issue was generated by a target device that started responding
240us later having received a request in communication at 115200bps.
Sometimes, some messages received by the target were missing some of the
first bytes.

Fixes: 3a13884abe ("tty/serial: omap: empty the RX FIFO at the end of half-duplex TX")
Signed-off-by: Dario Binacchi <dariobin@libero.it>
Link: https://lore.kernel.org/r/20210418094705.27014-1-dariobin@libero.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:07:07 +02:00
Dario Binacchi
45f6b6db53 serial: omap: don't disable rs485 if rts gpio is missing
There are rs485 transceivers (e.g. MAX13487E/MAX13488E) which
automatically disable or enable the driver and receiver to keep the bus
in the correct state.
In these cases we don't need a GPIO for flow control.

Fixes: 4a0ac0f55b ("OMAP: add RS485 support")
Signed-off-by: Dario Binacchi <dariobin@libero.it>
Link: https://lore.kernel.org/r/20210415210945.25863-1-dariobin@libero.it
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:06:59 +02:00
Johan Hovold
cea37afd28 serial: stm32: defer sysrq processing
Use the uart_unlock_and_check_sysrq() helper to defer sysrq processing
until receive processing is done and the port lock has been released.

This allows cleaning up the console_write() implementation by not having
to work around the recursive sysrq case (by dropping locking completely)
and also makes the console code work with PREEMPT_RT by no longer
relying on local_irq_save().

Reviewed-by: Valentin Caron<valentin.caron@foss.st.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-4-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:04:26 +02:00
Johan Hovold
e359b4411c serial: stm32: fix threaded interrupt handling
When DMA is enabled the receive handler runs in a threaded handler, but
the primary handler up until very recently neither disabled interrupts
in the device or used IRQF_ONESHOT. This would lead to a deadlock if an
interrupt comes in while the threaded receive handler is running under
the port lock.

Commit ad76768124 ("serial: stm32: fix a deadlock condition with
wakeup event") claimed to fix an unrelated deadlock, but unfortunately
also disabled interrupts in the threaded handler. While this prevents
the deadlock mentioned in the previous paragraph it also defeats the
purpose of using a threaded handler in the first place.

Fix this by making the interrupt one-shot and not disabling interrupts
in the threaded handler.

Note that (receive) DMA must not be used for a console port as the
threaded handler could be interrupted while holding the port lock,
something which could lead to a deadlock in case an interrupt handler
ends up calling printk.

Fixes: ad76768124 ("serial: stm32: fix a deadlock condition with wakeup event")
Fixes: 3489187204 ("serial: stm32: adding dma support")
Cc: stable@vger.kernel.org      # 4.9
Cc: Alexandre TORGUE <alexandre.torgue@st.com>
Cc: Gerald Baeza <gerald.baeza@st.com>
Reviewed-by: Valentin Caron<valentin.caron@foss.st.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-3-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:04:26 +02:00
Johan Hovold
75f4e830fa serial: do not restore interrupt state in sysrq helper
The uart_unlock_and_check_sysrq() helper can be used to defer processing
of sysrq until the interrupt handler has released the port lock and is
about to return.

Since commit 81e2073c17 ("genirq: Disable interrupts for force
threaded handlers") interrupt handlers that are not explicitly requested
as threaded are always called with interrupts disabled and there is no
need to save the interrupt state when taking the port lock.

Instead of adding another sysrq helper for when the interrupt state has
not needlessly been saved, drop the state parameter from
uart_unlock_and_check_sysrq() and update its callers to no longer
explicitly disable interrupts in their interrupt handlers.

Cc: Joel Stanley <joel@jms.id.au>
Cc: Andrew Jeffery <andrew@aj.id.au>
Cc: Andy Gross <agross@kernel.org>
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210416140557.25177-2-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:04:26 +02:00
Colin Ian King
86eb032675 tty: synclink_gt: remove redundant initialization of variable count
The variable count is being initialized with a value that is
never read and it is being updated later with a new value.  The
initialization is redundant and can be removed.

Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Addresses-Coverity: ("Unused value")
Link: https://lore.kernel.org/r/20210420105718.377086-1-colin.king@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:01:59 +02:00
Ulrich Hecht
f9f5498300 serial: sh-sci: remove obsolete latency workaround
Since the transition to hrtimers there is no more need to set a minimum
RX timeout to work around latency issues.

Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu>
Link: https://lore.kernel.org/r/20210415093547.21639-1-uli+renesas@fpond.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 12:59:16 +02:00
Greg Kroah-Hartman
5ffa6e344a tty: clean include/linux/tty.h up
There are a lot of tty-core-only functions that are listed in
include/linux/tty.h.  Move them to drivers/tty/tty.h so that no one else
can accidentally call them or think that they are public functions.

Cc: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20210408125134.3016837-14-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-15 10:32:17 +02:00