When a serial port gets faulty or gets flooded with inputs, its interrupt
handler starts to work double time to get the characters to the workqueue
for the tty layer to handle them. When this busy time on the serial/tty
subsystem happens during boot, where it is also busy on the userspace
trying to initialise, some processes can continuously get preempted
and will be on hold until the interrupts subside.
The fix is to backoff on processing received characters for a specified
amount of time when an input overrun is seen (received a new character
before the previous one is processed). This only stops receive and will
continue to transmit characters to serial port. After the backoff period
is done, it receive will be re-enabled. This is optional and will only
be enabled by setting 'overrun-throttle-ms' in the dts.
Signed-off-by: Darwin Dingel <darwin.dingel@alliedtelesis.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Disable M_TX_FIFO_WATERMARK_EN after we've sent all data for a given
transaction so we don't continue to receive a flurry of free space
interrupts while waiting for the M_CMD_DONE notification. Re-enable the
watermark when establishing the next transaction.
Also clear the watermark interrupt after filling the FIFO so we do not
receive notification again prior to actually having free space.
Signed-off-by: Ryan Case <ryandcase@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On (H)SCIF, sci_submit_rx() is called in the receive interrupt handler.
Hence if DMA submission fails, the interrupt handler should resume
handling reception using PIO, else no more data is received.
Make sci_submit_rx() return an error indicator, so the receive interrupt
handler can act appropriately.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When falling back to PIO, active_rx must be set to a different value
than cookie_rx[i], else sci_dma_rx_find_active() will incorrectly find a
match, leading to a NULL pointer dereference in rx_timer_fn() later.
Use zero instead, which is the same value as after driver
initialization.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some callers of sci_submit_rx() hold the port spinlock, others don't.
During fallback to PIO, the driver needs to obtain the port spinlock.
If the lock was already held, spinlock recursion is detected, causing a
deadlock: BUG: spinlock recursion on CPU#0.
Fix this by adding a flag parameter to sci_submit_rx() for the caller to
indicate the port spinlock is already held, so spinlock recursion can be
avoided.
Move the spin_lock_irqsave() up, so all DMA disable steps are protected,
which is safe as the recently introduced dmaengine_terminate_async() can
be called in atomic context.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here are three small tty driver fixes for 4.20-rc6
Nothing major, just some bug fixes for reported issues. Full details
are in the shortlog.
All of these have been in linux-next for a while with no reported
issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXAz36A8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ymYQgCgqA04cNFcelv38uoh9I1+AtOCRtEAnA64BAPe
HSAR9D0dbU2kb7vmIHg8
=vppK
-----END PGP SIGNATURE-----
Merge tag 'tty-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty driver fixes from Greg KH:
"Here are three small tty driver fixes for 4.20-rc6
Nothing major, just some bug fixes for reported issues. Full details
are in the shortlog.
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var()
tty: serial: 8250_mtk: always resume the device in probe.
tty: do not set TTY_IO_ERROR flag if console port
Here are some small USB fixes for 4.20-rc6
The "largest" here are some xhci fixes for reported issues. Also here
is a USB core fix, some quirk additions, and a usb-serial fix which
required the export of one of the tty layer's functions to prevent code
duplication. The tty maintainer agreed with this change.
All of these have been in linux-next with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCXAz3WA8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+yl+mwCgox0WZiO3qfnpQsIrJ5gJFCTrcmMAoMBC5jDf
e81bwzu507PcqvEXh+rg
=giw6
-----END PGP SIGNATURE-----
Merge tag 'usb-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are some small USB fixes for 4.20-rc6
The "largest" here are some xhci fixes for reported issues. Also here
is a USB core fix, some quirk additions, and a usb-serial fix which
required the export of one of the tty layer's functions to prevent
code duplication. The tty maintainer agreed with this change.
All of these have been in linux-next with no reported issues"
* tag 'usb-4.20-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
xhci: Prevent U1/U2 link pm states if exit latency is too long
xhci: workaround CSS timeout on AMD SNPS 3.0 xHC
USB: check usb_get_extra_descriptor for proper size
USB: serial: console: fix reported terminal settings
usb: quirk: add no-LPM quirk on SanDisk Ultra Flair device
USB: Fix invalid-free bug in port_over_current_notify()
usb: appledisplay: Add 27" Apple Cinema Display
This patch is trying to fix KE issue due to
"BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198"
reported by Syzkaller scan."
[26364:syz-executor0][name:report8t]BUG: KASAN: global-out-of-bounds in param_set_kgdboc_var+0x194/0x198
[26364:syz-executor0][name:report&]Read of size 1 at addr ffffff900e44f95f by task syz-executor0/26364
[26364:syz-executor0][name:report&]
[26364:syz-executor0]CPU: 7 PID: 26364 Comm: syz-executor0 Tainted: G W 0
[26364:syz-executor0]Call trace:
[26364:syz-executor0][<ffffff9008095cf8>] dump_bacIctrace+Ox0/0x470
[26364:syz-executor0][<ffffff9008096de0>] show_stack+0x20/0x30
[26364:syz-executor0][<ffffff90089cc9c8>] dump_stack+Oxd8/0x128
[26364:syz-executor0][<ffffff90084edb38>] print_address_description +0x80/0x4a8
[26364:syz-executor0][<ffffff90084ee270>] kasan_report+Ox178/0x390
[26364:syz-executor0][<ffffff90084ee4a0>] _asan_report_loadi_noabort+Ox18/0x20
[26364:syz-executor0][<ffffff9008b092ac>] param_set_kgdboc_var+Ox194/0x198
[26364:syz-executor0][<ffffff900813af64>] param_attr_store+Ox14c/0x270
[26364:syz-executor0][<ffffff90081394c8>] module_attr_store+0x60/0x90
[26364:syz-executor0][<ffffff90086690c0>] sysfs_kl_write+Ox100/0x158
[26364:syz-executor0][<ffffff9008666d84>] kernfs_fop_write+0x27c/0x3a8
[26364:syz-executor0][<ffffff9008508264>] do_loop_readv_writev+0x114/0x1b0
[26364:syz-executor0][<ffffff9008509ac8>] do_readv_writev+0x4f8/0x5e0
[26364:syz-executor0][<ffffff9008509ce4>] vfs_writev+0x7c/Oxb8
[26364:syz-executor0][<ffffff900850ba64>] SyS_writev+Oxcc/0x208
[26364:syz-executor0][<ffffff90080883f0>] elO_svc_naked +0x24/0x28
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:report&]The buggy address belongs to the variable:
[26364:syz-executor0][name:report&] kgdb_tty_line+Ox3f/0x40
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:report&]Memory state around the buggy address:
[26364:syz-executor0] ffffff900e44f800: 00 00 00 00 00 04 fa fa fa fa fa fa 00 fa fa fa
[26364:syz-executor0] ffffff900e44f880: fa fa fa fa 00 fa fa fa fa fa fa fa 00 fa fa fa
[26364:syz-executor0]> ffffff900e44f900: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
[26364:syz-executor0][name:report&] ^
[26364:syz-executor0] ffffff900e44f980: 00 fa fa fa fa fa fa fa 04 fa fa fa fa fa fa fa
[26364:syz-executor0] ffffff900e44fa00: 04 fa fa fa fa fa fa fa 00 fa fa fa fa fa fa fa
[26364:syz-executor0][name:report&]
[26364:syz-executor0][name:panic&]Disabling lock debugging due to kernel taint
[26364:syz-executor0]------------[cut here]------------
After checking the source code, we've found there might be an out-of-bounds
access to "config[len - 1]" array when the variable "len" is zero.
Signed-off-by: Macpaul Lin <macpaul@gmail.com>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit eca42d4cf3.
During review it was rejected, so drop it from the tree.
Cc: Rajan Vaja <RAJANV@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It seems like when ldsem_down_read() fails with timeout, it misses
update for sem->wait_readers. By that reason, when writer finally
releases write end of the semaphore __ldsem_wake_readers() does adjust
sem->count with wrong value:
sem->wait_readers * (LDSEM_ACTIVE_BIAS - LDSEM_WAIT_BIAS)
I.e, if update comes with 1 missed wait_readers decrement, sem->count
will be 0x100000001 which means that there is active reader and it'll
make any further writer to fail in acquiring the semaphore.
It looks like, this is a dead-code, because ldsem_down_read() is never
called with timeout different than MAX_SCHEDULE_TIMEOUT, so it might be
worth to delete timeout parameter and error path fall-back..
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure under CONFIG_LOCKDEP that each change to line discipline
is done with held write semaphor.
Otherwise potential reader will have a good time dereferencing
incomplete/uninitialized ldisc.
An exception here is tty_ldisc_open(), as it's called without ldisc_sem
locked by tty_init_dev() => tty_ldisc_setup() for the tty->link.
It seem valid as tty_init_dev() will call tty_driver_install_tty()
which will find ops->install(). Install will establish tty->link in
pty_common_install(), just after allocation of slave tty with
alloc_tty_struct(). So, no one should have a reference to slave pty yet.
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
For some reason ldsem has its own lockdep wrappers, make them go away.
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There might be situations where tty_ldisc_lock() has blocked, but there
is already IO on tty and it prevents line discipline changes.
It might theoretically turn into dead-lock.
Basically, provide more priority to pending tty_ldisc_lock() than to
servicing reads/writes over tty.
User-visible issue was reported by Mikulas where on pa-risc with
Debian 5 reboot took either 80 seconds, 3 minutes or 3:25 after proper
locking in tty_reopen().
Cc: Jiri Slaby <jslaby@suse.com>
Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tty_ldisc_reinit() doesn't race with neither tty_ldisc_hangup()
nor set_ldisc() nor tty_ldisc_release() as they use tty lock.
But it races with anyone who expects line discipline to be the same
after hoding read semaphore in tty_ldisc_ref().
We've seen the following crash on v4.9.108 stable:
BUG: unable to handle kernel paging request at 0000000000002260
IP: [..] n_tty_receive_buf_common+0x5f/0x86d
Workqueue: events_unbound flush_to_ldisc
Call Trace:
[..] n_tty_receive_buf2
[..] tty_ldisc_receive_buf
[..] flush_to_ldisc
[..] process_one_work
[..] worker_thread
[..] kthread
[..] ret_from_fork
tty_ldisc_reinit() should be called with ldisc_sem hold for writing,
which will protect any reader against line discipline changes.
Cc: Jiri Slaby <jslaby@suse.com>
Cc: stable@vger.kernel.org # b027e2298b ("tty: fix data race between tty_init_dev and flush of buf")
Reviewed-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: syzbot+3aa9784721dfb90e984d@syzkaller.appspotmail.com
Tested-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Tested-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ldsem_down_read() will sleep if there is pending writer in the queue.
If the writer times out, readers in the queue should be woken up,
otherwise they may miss a chance to acquire the semaphore until the last
active reader will do ldsem_up_read().
There was a couple of reports where there was one active reader and
other readers soft locked up:
Showing all locks held in the system:
2 locks held by khungtaskd/17:
#0: (rcu_read_lock){......}, at: watchdog+0x124/0x6d1
#1: (tasklist_lock){.+.+..}, at: debug_show_all_locks+0x72/0x2d3
2 locks held by askfirst/123:
#0: (&tty->ldisc_sem){.+.+.+}, at: ldsem_down_read+0x46/0x58
#1: (&ldata->atomic_read_lock){+.+...}, at: n_tty_read+0x115/0xbe4
Prevent readers wait for active readers to release ldisc semaphore.
Link: lkml.kernel.org/r/20171121132855.ajdv4k6swzhvktl6@wfg-t540p.sh.intel.com
Link: lkml.kernel.org/r/20180907045041.GF1110@shao2-debian
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysrq_do_reset() is called in softirq context, so it cannot call
sync() directly. Instead, call orderly_reboot(), which creates a work
item to run /sbin/reboot, or do emergency_sync and restart if the
command fails.
Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
serial8250_register_8250_port calls uart_config_port, which calls
config_port on the port before it tries to power on the port. So we need
the port to be on before calling serial8250_register_8250_port. Change
the code to always do a runtime resume in probe before registering port,
and always do a runtime suspend in remove.
This basically reverts the change in commit 68e5fc4a25 ("tty: serial:
8250_mtk: use pm_runtime callbacks for enabling"), but still use
pm_runtime callbacks.
Fixes: 68e5fc4a25 ("tty: serial: 8250_mtk: use pm_runtime callbacks for enabling")
Signed-off-by: Peter Shih <pihsun@chromium.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The USB-serial console implementation has never reported the actual
terminal settings used. Despite storing the corresponding cflags in its
struct console, these were never honoured on later tty open() where the
tty termios would be left initialised to the driver defaults.
Unlike the serial console implementation, the USB-serial code calls
subdriver open() already at console setup. While calling set_termios()
and write() before open() looks like it could work for some USB-serial
drivers, others definitely do not expect this, so modelling this after
serial core is going to be intrusive, if at all possible.
Instead, use a (renamed) tty helper to save the termios data used at
console setup so that the tty termios reflects the actual terminal
settings after a subsequent tty open().
Note that the calls to tty_init_termios() (tty_driver_install()) and
tty_save_termios() are serialised using the disconnect mutex.
This specifically fixes a regression that was triggered by a recent
change adding software flow control to the pl2303 driver: a getty trying
to disable flow control while leaving the baud rate unchanged would now
also set the baud rate to the driver default (prior to the flow-control
change this had been a noop).
Fixes: 7041d9c3f0 ("USB: serial: pl2303: add support for tx xon/xoff flow control")
Cc: stable <stable@vger.kernel.org> # 4.18
Cc: Florian Zumbiehl <florz@florz.de>
Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Modify uart register to support DMA function.
Signed-off-by: Long Cheng <long.cheng@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Existing driver checks for alternate clock if devm_clk_get() fails
and returns error code for last clock failure. If xilinx_uartps is
called before clock driver, devm_clk_get() returns -EPROBE_DEFER.
In this case, probe should not check for alternate clock as main
clock is already present in DTS and return -EPROBE_DEFER only.
This patch fixes it by not checking for alternate clock when main
clock get returns -EPROBE_DEFER.
Signed-off-by: Rajan Vaja <rajan.vaja@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Transfers were being divided into device FIFO sized (64 byte max)
operations which would poll for completion within a spin_lock_irqsave /
spin_unlock_irqrestore block. This both made things slow by waiting for
the FIFO to completely drain before adding further data and would also
result in softlocks on large transmissions.
This patch allows larger transfers with continuous FIFO additions as
space becomes available and removes polling from the interrupt handler.
Signed-off-by: Ryan Case <ryandcase@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 20d8e8611e.
As David Miller points out, it's wrong.
Reported-by: David Miller <davem@davemloft.net>
Cc: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
This place is not doing this, so fix it.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Document the asynchronous serdev_device_write_buf() and synchronous
serdev_device_write() functions using kernel-doc.
Specifically, mention that writing data only means that data has been
buffered by the controller, and that the synchronous helper depends on
serdev_device_write_wakeup() being called in the driver write_wakeup()
callback.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allow the synchronous serdev_device_write() helper to be interrupted.
This is useful for cases where I/O is performed on behalf of user space
and we don't want to block indefinitely when using flow control.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make the synchronous serdev_device_write() helper behave analogous to
the asynchronous serdev_device_write_buf() by returning the number of
bytes written (or rather buffered) also on timeout.
This will allow drivers to distinguish the case where data was partially
written from the case where no data was written.
Also update the only two users that checked the return value.
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use zero to indicate infinite timeout for the synchronous
serdev_device_write() helper.
This allows drivers to specify an infinite timeout without knowing about
serdev implementation details, while also allowing the same timeout
argument to be used for both serdev_device_write() and
serdev_device_wait_until_sent().
Note that passing zero to the current helper makes no sense; just call
the asynchronous serdev_device_write_buf() directly instead.
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysrq_handle_crash() currently forces a crash by dereferencing a
NULL pointer, which is undefined behavior in C. Just call panic()
instead, which is simpler and doesn't depend on compiler specific
handling of the undefined behavior.
Remove the comment on why the RCU lock needs to be released, it isn't
accurate anymore since the crash now isn't handled by the page fault
handler (for reference: the comment was added by commit 984cf355ae
("sysrq: Fix warning in sysrq generated crash.")). Releasing the lock
is still good practice though.
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
bl_idle_init() doesn't do that, so fix it.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since Commit 761ed4a945 ('tty: serial_core: convert uart_close to use
tty_port_close') and Commit 4dda864d73 ('tty: serial_core: Fix serial
console crash on port shutdown), a serial port which is used as
console can be stuck when logging out if there is a remained process.
After logged out, agetty will try to grab the serial port but it will
be failed because the previous process did not release the port
correctly. To fix this, TTY_IO_ERROR bit should not be enabled of
tty_port_close if the port is console port.
Reproduce step:
- Run background processes from serial console
$ while true; do sleep 10; done &
- Log out
$ logout
-> Stuck
- Read journal log by journalctl | tail
Jan 28 16:07:01 ubuntu systemd[1]: Stopped Serial Getty on ttyAMA0.
Jan 28 16:07:01 ubuntu systemd[1]: Started Serial Getty on ttyAMA0.
Jan 28 16:07:02 ubuntu agetty[1643]: /dev/ttyAMA0: not a tty
Fixes: 761ed4a945 ("tty: serial_core: convert uart_close to use tty_port_close")
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Rob Herring <robh@kernel.org>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Chanho Park <parkch98@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The ipg clock only needs to be unprepared in case preparing
per clock fails. The ipg clock has already disabled at the point.
Fixes: 1cf93e0d54 ("serial: imx: remove the uart_console() check")
Signed-off-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The baudrate derivation relies on the state of the programmable over
sampling stack (OSAMP register) being empty, while never initializing
it.
Set all the fields of this register to 0 (except reserved areas) to
ensure a x16 divisor, as assumed by the driver.
The suspend/resume callbacks are untouched because they already
save/restore correctly this register.
Suggested-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current comment in ->set_baud_rate() is rather incomplete as it
fails to describe what are the actual stages for the baudrate
derivation. Replace this comment with something more explicit and
close to the functional specification. Also adapt the variable names
to it.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
This place is not doing this, so fix it.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
of_find_node_by_path() acquires a reference to the node
returned by it and that reference needs to be dropped by its caller.
This place is not doing this, so fix it.
Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pointer port is dereferenced on port->private_data when assigning pointer
pdata before port is null checked, leading to a potential null pointer
dereference. Fix this by assigning pdata after the null pointer check on
port.
Detected by CoverityScan, CID#1475434 ("Dereference before null check")
Fixes: 3b209d253e ("serial-uartlite: Do not use static struct uart_driver out of probe()")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Here are some small tty fixes for 4.20-rc2
One of these missed the original 4.19-final release, I missed that I
hadn't done a pull request for it as it was in linux-next and my branch
for a long time, that's my fault.
The others are small, fixing some reported issues and finally fixing the
termios mess for alpha so that glibc has a chance to implement some
missing functionality that has been pending for many years now.
All of these have been in linux-next with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
iG0EABECAC0WIQT0tgzFv3jCIUoxPcsxR9QN2y37KQUCW+cpjw8cZ3JlZ0Brcm9h
aC5jb20ACgkQMUfUDdst+ymcQQCgt4IbK1wm/bxZqikhg64GS7J7IdkAoLoK1gKi
Sq+KsJX2qr4GuAcxJIjr
=uyeQ
-----END PGP SIGNATURE-----
Merge tag 'tty-4.20-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial fixes from Greg KH:
"Here are some small tty fixes for 4.20-rc2
One of these missed the original 4.19-final release, I missed that I
hadn't done a pull request for it as it was in linux-next and my
branch for a long time, that's my fault.
The others are small, fixing some reported issues and finally fixing
the termios mess for alpha so that glibc has a chance to implement
some missing functionality that has been pending for many years now.
All of these have been in linux-next with no reported issues"
* tag 'tty-4.20-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
serial: sh-sci: Fix could not remove dev_attr_rx_fifo_timeout
arch/alpha, termios: implement BOTHER, IBSHIFT and termios2
termios, tty/tty_baudrate.c: fix buffer overrun
vt: fix broken display when running aptitude
serial: sh-sci: Fix receive on SCIFA/SCIFB variants with DMA
This patch fixes an issue that the sci_remove() could not remove
dev_attr_rx_fifo_timeout because uart_remove_one_port() set
the port->port.type to PORT_UNKNOWN.
Reported-by: Hiromitsu Yamasaki <hiromitsu.yamasaki.ym@renesas.com>
Fixes: 5d23188a47 ("serial: sh-sci: make RX FIFO parameters tunable via sysfs")
Cc: <stable@vger.kernel.org> # v4.11+
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Ulrich Hecht <uli+renesas@fpond.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Let's take advantage of the new ("serial: core: Allow processing sysrq
at port unlock time") to handle sysrqs more cleanly.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Let's take advantage of the new ("serial: core: Allow processing sysrq
at port unlock time") to handle sysrqs more cleanly.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The geni serial driver already had some sysrq code in it, but since
SUPPORT_SYSRQ wasn't defined the code didn't do anything useful.
Let's make it useful by adding that define using the same formula
found in other serial drivers.
In order to prevent deadlock, we'll take a page from the
'msm_serial.c' where the spinlock is released around
uart_handle_sysrq_char(). This seemed better than copying from
'8250_port.c' where we skip locking in the console_write function
since the '8250_port.c' method can cause lockdep warnings when
dropping into kgdb.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It is way too easy to miss enabling SERIAL_OF_PLATFORM which would
result in the inability for the kernel to have a valid console device,
which can be seen with:
Warning: unable to open an initial console.
and then:
Run /init as init process
Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000100
Since SERIAL_OF_PLATFORM already depends on SERIAL_8250 && OF there
really is no drawback to defaulting this config to the value of
SERIAL_8250.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tx_empty is not used after setting its value. It is safe to remove
the unused variable.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Reviewed-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We should get 'driver_data' from 'struct device' directly. Going via
platform_device is an unneeded step back and forth.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
UART driver checks for the PM state and denies suspend if state is ACTIVE.
This makes UART to deny suspend when client keeps port open which is not
correct. Instead follow framework and obey suspend-resume callbacks.
Signed-off-by: Mukesh Kumar Savaliya <msavaliy@codeaurora.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If you turn on CONFIG_KGDB then you'll get CONFIG_CONSOLE_POLL
selected.
If you have CONFIG_CONSOLE_POLL selected then the GENI serial driver
was setting RX_BYTES_PW to 1 for _all_ UART ports.
This doesn't seem like such a good idea. Let's only set RX_BYTES_PW
to 1 for the console port.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Mukesh Kumar Savaliya <msavaliy@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
