Add the documentation for the electrical properties for the iMX SATA
controller. There are many values for these, and listing them would
be error prone. Refer readers to the device documentation and driver
source code for these details.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
To: Tejun Heo <tj@kernel.org>,linux-ide@vger.kernel.org
The Freescale i.MX SATA controller mostly conforms to the AHCI
interface, but there are some special extensions at integration level
like clocks settings and hardware parameters.
Let's create a separate bindings doc for imx sata controller, so that
more imx specific properties can be added later without messing up the
generic ahci-platform bindings.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
This can be used in virtual networking applications, and
may have other uses as well. The option is disabled by
default.
A specific use case is setting up virtual routers, bridges, and
hosts on a single OS without the use of network namespaces or
virtual machines. With proper use of ip rules, routing tables,
veth interface pairs and/or other virtual interfaces,
and applications that can bind to interfaces and/or IP addresses,
it is possibly to create one or more virtual routers with multiple
hosts attached. The host interfaces can act as IPv6 systems,
with radvd running on the ports in the virtual routers. With the
option provided in this patch enabled, those hosts can now properly
obtain IPv6 addresses from the radvd.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In addition to consolidating the or1k-pic with other interrupt
controllers, this makes OpenRISC less tied to its on-cpu
interrupt controller.
All or1k-pic specific parts are moved out of irq.c and into
drivers/irqchip/irq-or1k-pic.c
In that transition, the functionality have been divided into
three chip variants.
One that handles level triggered interrupts, one that handles edge
triggered interrupts and one that handles the interrupt
controller that is present in the or1200 OpenRISC cpu
implementation.
Signed-off-by: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Link: https://lkml.kernel.org/r/1401136302-27654-1-git-send-email-stefan.kristiansson@saunalahti.fi
Acked-by: Jonas Bonn <jonas@southpole.se>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
On certain platforms such as DRA7, SPIs 0, 1, 2, 3, 5, 6, 10, 131,
132, 133 are direct wired to hardware blocks bypassing crossbar.
This quirky implementation is *NOT* supposed to be the expectation
of crossbar hardware usage. However, these are already marked in our
description of the hardware with SKIP and RESERVED where appropriate.
Unfortunately, we need to be able to refer to these hardwired IRQs.
So, to request these, crossbar driver can use the existing information
from it's table that these SKIP/RESERVED maps are direct wired sources
and generic allocation/programming of crossbar should be avoided.
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-17-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Currently we attempt to map any crossbar value to an IRQ, however,
this is not correct from hardware perspective. There is a max crossbar
event number upto which hardware supports. So describe the same in
device tree using 'ti,max-crossbar-sources' property and use it to
validate requests.
[ jac - remove MAX_SOURCES from binding doc, use integer because we
shouldn't put implementation details in the binding docs ]
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-14-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Since crossbar is s/w configurable, the initial settings of the
crossbar cannot be assumed to be sane. This implies that:
a) On initialization all un-reserved crossbars must be initialized to
a known 'safe' value.
b) When unmapping the interrupt, the safe value must be written to
ensure that the crossbar mapping matches with interrupt controller
usage.
So provide a safe value in the dt data to map if
'0' is not safe for the platform and use it during init and unmap
While at this, fix the below checkpatch warning.
Fixes checkpatch warning:
WARNING: Unnecessary space before function pointer arguments
#37: FILE: drivers/irqchip/irq-crossbar.c:37:
+ void (*write) (int, int);
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Link: https://lkml.kernel.org/r/1403766634-18543-5-git-send-email-r.sricharan@ti.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
The MAX98091 CODEC is the same as MAX98090 CODEC, but with an extra
microphone. Existing driver for MAX98090 CODEC already has support
for MAX98091 CODEC. Adding proper compatible string so that MAX98091
CODEC can be specified from device tree.
Signed-off-by: Wonjoon Lee <woojoo.lee@samsung.com>
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Tushar Behera <tushar.b@samsung.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Pull ARM fixes from Russell King:
"Another round of ARM fixes. The largest change here is the L2 changes
to work around problems for the Armada 37x/380 devices, where most of
the size comes down to comments rather than code.
The other significant fix here is for the ptrace code, to ensure that
rewritten syscalls work as intended. This was pointed out by Kees
Cook, but Will Deacon reworked the patch to be more elegant.
The remainder are fairly trivial changes"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: 8087/1: ptrace: reload syscall number after secure_computing() check
ARM: 8086/1: Set memblock limit for nommu
ARM: 8085/1: sa1100: collie: add top boot mtd partition
ARM: 8084/1: sa1100: collie: revert back to cfi_probe
ARM: 8080/1: mcpm.h: remove unused variable declaration
ARM: 8076/1: mm: add support for HW coherent systems in PL310 cache
Jonathan writes:
Second round of new drivers and cleanups for IIO in the 3.17 cycle.
New drivers
* mcp4902, mcp4912 and mcp4922 SPI DAC driver.
* max1027, max1029 and max1031 SPI ADC driver.
Cleanups
* cm32181 - use devm APIs to simplify error paths.
* ak8975 - use devm APIs to simplify error paths.
* ad9850 - drop some unused defines and an unnecessary goto.
* hmc5843 - add missing devices to the device id table and the documentation.
* ad9832 - small formatting cleanups.
* sca3000 - hide direct use of the stufftoread element by adding a
data_available function. This is a precursor for the addition of buffer
watermarks to the subsystem but stands as a good cleanup on its own.
When a PL310 cache is used on a system that provides hardware
coherency, the outer cache sync operation is useless, and can be
skipped. Moreover, on some systems, it is harmful as it causes
deadlocks between the Marvell coherency mechanism, the Marvell PCIe
controller and the Cortex-A9.
To avoid this, this commit introduces a new Device Tree property
'arm,io-coherent' for the L2 cache controller node, valid only for the
PL310 cache. It identifies the usage of the PL310 cache in an I/O
coherent configuration. Internally, it makes the driver disable the
outer cache sync operation.
Note that technically speaking, a fully coherent system wouldn't
require any of the other .outer_cache operations. However, in
practice, when booting secondary CPUs, these are not yet coherent, and
therefore a set of cache maintenance operations are necessary at this
point. This explains why we keep the other .outer_cache operations and
only ->sync is disabled.
While in theory any write to a PL310 register could cause the
deadlock, in practice, disabling ->sync is sufficient to workaround
the deadlock, since the other cache maintenance operations are only
used in very specific situations.
Contrary to previous versions of this patch, this new version does not
simply NULL-ify the ->sync member, because the l2c_init_data
structures are now 'const' and therefore cannot be modified, which is
a good thing. Therefore, this patch introduces a separate
l2c_init_data instance, called of_l2c310_coherent_data.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull spi fixes from Mark Brown:
"A few driver specific fixes, the biggest one being a fix for the newly
added Qualcomm SPI controller driver to make it not use its internal
chip select due to hardware bugs, replacing it with GPIOs"
* tag 'spi-v3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
spi: qup: Remove chip select function
spi: qup: Fix order of spi_register_master
spi: sh-sci: fix use-after-free in sh_sci_spi_remove()
spi/pxa2xx: fix incorrect SW mode chipselect setting for BayTrail LPSS SPI
Sound data needs to be sent to R-Car sound SSI when playback.
But, there are 2 interfaces for it.
1st is SSITDR/SSIRDR which are mapped on SSI.
2nd is SSIn_BUSIF which are mapped on SSIU.
2nd SSIn_BUSIF is used when DMA transfer,
and it is always used if sound data came from via SRC.
But, we can use it when SSI+DMA case too.
(Current driver is assuming 1st SSITDR/SSIRDR for it)
2nd SSIn_BUSIF can be used as FIFO.
This is very helpful/useful for SSI+DMA.
But DMA address / DMA ID are not same between 1st/2nd cases.
This patch care about these settings.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
This driver add partial support of the
maxim 1027/1029/1031. Differential mode is not
supported.
It was tested on armadeus apf27 board.
Signed-off-by: Philippe Reynes <tremyfr@yahoo.fr>
Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Pull sound fixes from Takashi Iwai:
"Here includes a few patchset for fixing mostly HD-audio issues in
addition to a patch assuring the compress API bytes alignment and a
fix for the die-hard existing race condition at USB-audio
disconnection. The volume looks big in Realtek HD-audio code, but
it's just a translation of the fixup tables, and the actual changes
are rather trivial"
* tag 'sound-3.16-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: hda - restore BCLK M/N values when resuming HSW/BDW display controller
ALSA: usb-audio: Fix races at disconnection and PCM closing
ALSA: hda - Adjust speaker HPF and add LED support for HP Spectre 13
ALSA: hda - Make the pin quirk tables use the SND_HDA_PIN_QUIRK macro
ALSA: hda - Make a SND_HDA_PIN_QUIRK macro
ALSA: hda - Add pin quirk for Dell XPS 15
ALSA: hda - hdmi: call overridden init on resume
ALSA: hda - Fix usage of "model" module parameter
ALSA: compress: fix the struct alignment to 4 bytes
Pull hwmon fixes from Guenter Roeck:
"Various minor fixes"
* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (gpio-fan) Change name used in hwmon_device_register_with_groups
hwmon: (emc1403) Fix missing 'select REGMAP_I2C' in Kconfig
hwmon: (ntc_thermistor) Use the manufacturer name properly
devicetree: bindings: Document murata vendor prefix
hwmon: (w83l786ng) Report correct minimum fan speed
Pull networking fixes from David Miller:
1) Fix crash in ipvs tot_stats estimator, from Julian Anastasov.
2) Fix OOPS in nf_nat on netns removal, from Florian Westphal.
3) Really really really fix locking issues in slip and slcan tty write
wakeups, from Tyler Hall.
4) Fix checksum offloading in fec driver, from Fugang Duan.
5) Off by one in BPF instruction limit test, from Kees Cook.
6) Need to clear all TSO capability flags when doing software TSO in
tg3 driver, from Prashant Sreedharan.
7) Fix memory leak in vlan_reorder_header() error path, from Li
RongQing.
8) Fix various bugs in xen-netfront and xen-netback multiqueue support,
from David Vrabel and Wei Liu.
9) Fix deadlock in cxgb4 driver, from Li RongQing.
10) Prevent double free of no-cache DST entries, from Eric Dumazet.
11) Bad csum_start handling in skb_segment() leads to crashes when
forwarding, from Tom Herbert.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (76 commits)
net: fix setting csum_start in skb_segment()
ipv4: fix dst race in sk_dst_get()
net: filter: Use kcalloc/kmalloc_array to allocate arrays
trivial: net: filter: Change kerneldoc parameter order
trivial: net: filter: Fix typo in comment
net: allwinner: emac: Add missing free_irq
cxgb4: use dev_port to identify ports
xen-netback: bookkeep number of active queues in our own module
tg3: Change nvram command timeout value to 50ms
cxgb4: Not need to hold the adap_rcu_lock lock when read adap_rcu_list
be2net: fix qnq mode detection on VFs
of: mdio: fixup of_phy_register_fixed_link parsing of new bindings
at86rf230: fix irq setup
net: phy: at803x: fix coccinelle warnings
net/mlx4_core: Fix the error flow when probing with invalid VF configuration
tulip: Poll link status more frequently for Comet chips
net: huawei_cdc_ncm: increase command buffer size
drivers: net: cpsw: fix dual EMAC stall when connected to same switch
xen-netfront: recreate queues correctly when reconnecting
xen-netfront: fix oops when disconnected from backend
...
Pull ARM SoC fixes from Arnd Bergmann:
"A new set of bug fixes for 3.16, containing patches for seven
platforms:
at91:
- drivers/misc fix for Kconfig PWM symbol
- correction of several values in DT after conversion to CCF
- fix at91sam9261/at91sam9261ek mistake in slow crystal vs. slow RC osc
imx:
- Use GPIO for card CD/WP on imx51-babbage and eukrea-mbimxsd51,
because controller base CD/WP is not working in esdhc driver due to
runtime PM support
- A couple of random ventana gw5xxx board fixes
- Add IMX_IPUV3_CORE back to defconfig, which gets lost when moving
IPUv3 driver out of staging tree
- Fix enet/fec clock selection on imx6sl
- Fix display node on imx53-m53evk board
- A couple of Cubox-i updates from Russell, which were omitted from
the merge window due to dependency
integrator:
- fix an OF-related regression against 3.15
mvebu:
- mvebu (v7)
- Fix broken SoC ID detection
- Select ARM_CPU_SUSPEND for v7
- Remove armada38x compatible string (no users yet)
- Enable Dove SoC in mvebu_v7_defconfig
- kirkwood
- Fix phy-connection-type on GuruPlug board
qcom:
- enable gsbi driver in defconfig
- fix section mismatch warning in serial driver
samsung:
- use WFI macro in platform_do_lowpower because exynos cpuhotplug
includes a hardcoded WFI instruction and it causes compile error
in Thumb-2 mode.
- fix GIC reg sizes for exynos4 SoCs
- remove reset timer counter value during boot and resume for mct
to fix a big jump in printk timestamps
- fix pm code to check cortex-A9 for another exynos SoCs
- don't rely on firmware's secondary_cpu_start for mcpm
sti:
- Ethernet clocks were wrongly defined for STiH415/416 platforms
- STiH416 B2020 revision E DTS file name contained uppercase, change to
lowercase"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (33 commits)
ARM: at91/dt: sam9261: remove slow RC osc
ARM: at91/dt: define sam9261ek slow crystal frequency
ARM: at91/dt: sam9261: correctly define mainck
ARM: at91/dt: sam9n12: correct PLLA ICPLL and OUT values
ARM: at91/dt: sam9x5: correct PLLA ICPLL and OUT values
misc: atmel_pwm: fix Kconfig symbols
ARM: integrator: fix OF-related regression
ARM: mvebu: Fix the improper use of the compatible string armada38x using a wildcard
ARM: dts: kirkwood: fix phy-connection-type for Guruplug
ARM: EXYNOS: Don't rely on firmware's secondary_cpu_start for mcpm
ARM: dts: imx51-eukrea-mbimxsd51-baseboard: unbreak esdhc.
ARM: dts: imx51-babbage: Fix esdhc setup
ARM: dts: mx5: Move the display out of soc {} node
ARM: dts: mx5: Fix IPU port node placement
ARM: mvebu: select ARM_CPU_SUSPEND for Marvell EBU v7 platforms
ARM: mvebu: Fix broken SoC ID detection
ARM: imx_v6_v7_defconfig: Enable CONFIG_IMX_IPUV3_CORE
ARM: multi_v7_defconfig: Add QCOM GSBI driver
ARM: stih41x: Rename stih416-b2020-revE.dts to stih416-b2020e.dts
tty: serial: msm: Fix section mismatch warning
...
HP Spectre 13 has the IDT 92HD95 codec, and BIOS seems to set the
default high-pass filter in some "safer" range, which results in the
very soft tone from the built-in speakers in contrast to Windows.
Also, the mute LED control is missing, since 92HD95 codec still has no
HP-specific fixups for GPIO setups.
This patch adds these missing features: the HPF is adjusted by the
vendor-specific verb, and the LED is set up from a DMI string (but
with the default polarity = 0 assumption due to the incomplete BIOS on
the given machine).
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=74841
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Murata Manufacturing Co., Ltd is the vendor for
NTC (Negative Temperature coefficient) based Thermistors.
But, the driver extensively uses "NTC" as the vendor name.
This patch corrects the vendor name also updates the
compatibility strings according to the vendor-prefix.txt
Note: Drivers continue to support the previous compatible strings
but further addition of these compatible strings in device tree
is deprecated.
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Add Murata Manufacturing Co., Ltd. to the list of device tree
vendor prefixes.
Murata manufactures NTC (Negative Temperature Coefficient) based
Thermistors for small scale applications like Mobiles and PDAs.
Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Pull RCU fixes from Paul E. McKenney:
" This series includes the following:
1. Export a pair of debug-object interfaces for RCU that will
allow the slab allocators to avoid a recursion bug located
by Sasha Levin. Strictly speaking, this is not a regression,
but it would be good to enable the fix.
2. Address a serious performance regression on an open/close
micro-benchmark located by Dave Hansen. The offending commit
is ac1bea8578 (Make cond_resched() report RCU quiescent states). "
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch adds binding documentation for the Cirrus Logic CS4265 I2C CODEC.
Signed-off-by: Paul Handrigan <paul.handrigan@cirrus.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Add OF document for Cirrus Logic CLPS711X framebuffer driver.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
A 'softlockup' is defined as a bug that causes the kernel to loop in
kernel mode for more than a predefined period to time, without giving
other tasks a chance to run.
Currently, upon detection of this condition by the per-cpu watchdog
task, debug information (including a stack trace) is sent to the system
log.
On some occasions, we have observed that the "victim" rather than the
actual "culprit" (i.e. the owner/holder of the contended resource) is
reported to the user. Often this information has proven to be
insufficient to assist debugging efforts.
To avoid loss of useful debug information, for architectures which
support NMI, this patch makes it possible to improve soft lockup
reporting. This is accomplished by issuing an NMI to each cpu to obtain
a stack trace.
If NMI is not supported we just revert back to the old method. A sysctl
and boot-time parameter is available to toggle this feature.
[dzickus@redhat.com: add CONFIG_SMP in certain areas]
[akpm@linux-foundation.org: additional CONFIG_SMP=n optimisations]
[mq@suse.cz: fix warning]
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Jan Moskyto Matejka <mq@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Oleg reports a division by zero error on zero-length write() to the
percpu_pagelist_fraction sysctl:
divide error: 0000 [#1] SMP DEBUG_PAGEALLOC
CPU: 1 PID: 9142 Comm: badarea_io Not tainted 3.15.0-rc2-vm-nfs+ #19
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
task: ffff8800d5aeb6e0 ti: ffff8800d87a2000 task.ti: ffff8800d87a2000
RIP: 0010: percpu_pagelist_fraction_sysctl_handler+0x84/0x120
RSP: 0018:ffff8800d87a3e78 EFLAGS: 00010246
RAX: 0000000000000f89 RBX: ffff88011f7fd000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000010
RBP: ffff8800d87a3e98 R08: ffffffff81d002c8 R09: ffff8800d87a3f50
R10: 000000000000000b R11: 0000000000000246 R12: 0000000000000060
R13: ffffffff81c3c3e0 R14: ffffffff81cfddf8 R15: ffff8801193b0800
FS: 00007f614f1e9740(0000) GS:ffff88011f440000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007f614f1fa000 CR3: 00000000d9291000 CR4: 00000000000006e0
Call Trace:
proc_sys_call_handler+0xb3/0xc0
proc_sys_write+0x14/0x20
vfs_write+0xba/0x1e0
SyS_write+0x46/0xb0
tracesys+0xe1/0xe6
However, if the percpu_pagelist_fraction sysctl is set by the user, it
is also impossible to restore it to the kernel default since the user
cannot write 0 to the sysctl.
This patch allows the user to write 0 to restore the default behavior.
It still requires a fraction equal to or larger than 8, however, as
stated by the documentation for sanity. If a value in the range [1, 7]
is written, the sysctl will return EINVAL.
This successfully solves the divide by zero issue at the same time.
Signed-off-by: David Rientjes <rientjes@google.com>
Reported-by: Oleg Drokin <green@linuxhacker.ru>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Documentation/memory-hotplug.txt incorrectly states that the memory
driver "probe" interface is only supported on powerpc and is vague about
its application on x86. Clarify the platforms that make this interface
available if memory hotplug is enabled.
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit ac1bea8578 (Make cond_resched() report RCU quiescent states)
fixed a problem where a CPU looping in the kernel with but one runnable
task would give RCU CPU stall warnings, even if the in-kernel loop
contained cond_resched() calls. Unfortunately, in so doing, it introduced
performance regressions in Anton Blanchard's will-it-scale "open1" test.
The problem appears to be not so much the increased cond_resched() path
length as an increase in the rate at which grace periods complete, which
increased per-update grace-period overhead.
This commit takes a different approach to fixing this bug, mainly by
moving the RCU-visible quiescent state from cond_resched() to
rcu_note_context_switch(), and by further reducing the check to a
simple non-zero test of a single per-CPU variable. However, this
approach requires that the force-quiescent-state processing send
resched IPIs to the offending CPUs. These will be sent only once
the grace period has reached an age specified by the boot/sysfs
parameter rcutree.jiffies_till_sched_qs, or once the grace period
reaches an age halfway to the point at which RCU CPU stall warnings
will be emitted, whichever comes first.
Reported-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Christoph Lameter <cl@gentwo.org>
Cc: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
[ paulmck: Made rcu_momentary_dyntick_idle() as suggested by the
ktest build robot. Also fixed smp_mb() comment as noted by
Oleg Nesterov. ]
Merge with e552592e (Reduce overhead of cond_resched() checks for RCU)
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This patch removes the chip select function. Chip select should instead be
supported using GPIOs, defining the DT entry "cs-gpios", and letting the SPI
core assert/deassert the chip select as it sees fit.
The chip select control inside the controller is buggy. It is supposed to
automatically assert the chip select based on the activity in the controller,
but it is buggy and doesn't work at all. So instead we elect to use GPIOs.
Signed-off-by: Andy Gross <agross@codeaurora.org>
Signed-off-by: Mark Brown <broonie@linaro.org>
Pull i2c new drivers from Wolfram Sang:
"Here is a pull request from i2c hoping for the "new driver" rule.
Originally, I wanted to send this request during the merge window, but
code checkers with very recent additions complained, so a few fixups
were needed. So, some more time went by and I merged rc1 to get a
stable base"
So the "new driver" rule is really about drivers that people absolutely
need for the kernel to work on new hardware, which is not so much the
case for i2c. So I considered not pulling this, but eventually
relented.
Just for FYI: the whole (and only) point of "new drivers" is not that
new drivers cannot regress things (they can, and they have - by
triggering badly tested code on machines that never triggered that code
before), but because they can bring to life machines that otherwise
wouldn't be useful at all without the drivers.
So the new driver rule is for essential things that actual consumers
would care about, ie devices like networking or disk drivers that matter
to normal people (not server people - they run old kernels anyway, so
mainlining new drivers is irrelevant for them).
* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: sun6-p2wi: fix call to snprintf
i2c: rk3x: add NULL entry to the end of_device_id array
i2c: sun6i-p2wi: use proper return value in probe
i2c: sunxi: add P2WI (Push/Pull 2 Wire Interface) controller support
i2c: sunxi: add P2WI DT bindings documentation
i2c: rk3x: add driver for Rockchip RK3xxx SoC I2C adapter
