Add a new check for CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to reduce
the number of or's used in the ether_addr_equal comparison to very
slightly improve function performance.
Simplify the ether_addr_equal_64bits implementation.
Integrate and remove the zap_last_2bytes helper as it's now
used only once.
Remove the now unused compare_ether_addr function.
Update the unaligned-memory-access documentation to remove the
compare_ether_addr description and show how unaligned accesses
could occur with ether_addr_equal.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add Tahvo USB transceiver driver.
Based on old code from linux-omap tree. The original driver was written
by Juha Yrjölä, Tony Lindgren, and Timo Teräs.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Felipe Balbi <balbi@ti.com>
The 'max-speed' property is optional but defined in the ePAPR
specification and now supported by the Linux Device Tree parsing
infrastructure.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
John W. Linville says:
====================
Please pull this batch of updates intended for the 3.14 stream...
For the mac80211 bits, Johannes says:
"I have various improvements/cleanups/fixes all over, but the shortlog
shows that Luis's regulatory work and mesh work from the cozybit folks
are the biggest ones, along with the CSA fixes."
Along with that, we have big batches of updates to brcmfmac, rtlwifi,
and ath9k. There are updates to wcn36xx, rt2x00, and a handful of
others as well.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
With the introduction of TCP Small Queues, TSO auto sizing, and TCP
pacing, we can implement Automatic Corking in the kernel, to help
applications doing small write()/sendmsg() to TCP sockets.
Idea is to change tcp_push() to check if the current skb payload is
under skb optimal size (a multiple of MSS bytes)
If under 'size_goal', and at least one packet is still in Qdisc or
NIC TX queues, set the TCP Small Queue Throttled bit, so that the push
will be delayed up to TX completion time.
This delay might allow the application to coalesce more bytes
in the skb in following write()/sendmsg()/sendfile() system calls.
The exact duration of the delay is depending on the dynamics
of the system, and might be zero if no packet for this flow
is actually held in Qdisc or NIC TX ring.
Using FQ/pacing is a way to increase the probability of
autocorking being triggered.
Add a new sysctl (/proc/sys/net/ipv4/tcp_autocorking) to control
this feature and default it to 1 (enabled)
Add a new SNMP counter : nstat -a | grep TcpExtTCPAutoCorking
This counter is incremented every time we detected skb was under used
and its flush was deferred.
Tested:
Interesting effects when using line buffered commands under ssh.
Excellent performance results in term of cpu usage and total throughput.
lpq83:~# echo 1 >/proc/sys/net/ipv4/tcp_autocorking
lpq83:~# perf stat ./super_netperf 4 -t TCP_STREAM -H lpq84 -- -m 128
9410.39
Performance counter stats for './super_netperf 4 -t TCP_STREAM -H lpq84 -- -m 128':
35209.439626 task-clock # 2.901 CPUs utilized
2,294 context-switches # 0.065 K/sec
101 CPU-migrations # 0.003 K/sec
4,079 page-faults # 0.116 K/sec
97,923,241,298 cycles # 2.781 GHz [83.31%]
51,832,908,236 stalled-cycles-frontend # 52.93% frontend cycles idle [83.30%]
25,697,986,603 stalled-cycles-backend # 26.24% backend cycles idle [66.70%]
102,225,978,536 instructions # 1.04 insns per cycle
# 0.51 stalled cycles per insn [83.38%]
18,657,696,819 branches # 529.906 M/sec [83.29%]
91,679,646 branch-misses # 0.49% of all branches [83.40%]
12.136204899 seconds time elapsed
lpq83:~# echo 0 >/proc/sys/net/ipv4/tcp_autocorking
lpq83:~# perf stat ./super_netperf 4 -t TCP_STREAM -H lpq84 -- -m 128
6624.89
Performance counter stats for './super_netperf 4 -t TCP_STREAM -H lpq84 -- -m 128':
40045.864494 task-clock # 3.301 CPUs utilized
171 context-switches # 0.004 K/sec
53 CPU-migrations # 0.001 K/sec
4,080 page-faults # 0.102 K/sec
111,340,458,645 cycles # 2.780 GHz [83.34%]
61,778,039,277 stalled-cycles-frontend # 55.49% frontend cycles idle [83.31%]
29,295,522,759 stalled-cycles-backend # 26.31% backend cycles idle [66.67%]
108,654,349,355 instructions # 0.98 insns per cycle
# 0.57 stalled cycles per insn [83.34%]
19,552,170,748 branches # 488.244 M/sec [83.34%]
157,875,417 branch-misses # 0.81% of all branches [83.34%]
12.130267788 seconds time elapsed
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When booted with device tree, we may still have platform data passed
as auxdata. For am3517 this is needed for passing the interrupt_enable
and interrupt_disable callbacks that access the omap system control module
registers. These callback functions will eventually go away when we have
a separate system control module driver.
Some of the things that are currently passed as platform data we don't need
to set up as device tree properties as they are always the same on am3517.
So let's use a new compatible flag for those so we can get those from
the device tree match data.
Also note that we need to fix setting of phy_dev to NULL instead of an empty
string as the code later on uses that to find the first phy on the mdio bus.
This seems to have been caused by 5d69e0076a (net: davinci_emac: switch to
new mdio).
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ben Hutchings says:
====================
SIOCGHWTSTAMP ioctl
1. Add the SIOCGHWTSTAMP ioctl and update the timestamping
documentation.
2. Implement SIOCGHWTSTAMP in most drivers that support SIOCSHWTSTAMP.
3. Add a test program to exercise SIOC{G,S}HWTSTAMP.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This binding mainly serves to document the list of input and output pins
that may be used in a sound card's audio routing table.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Initially, this binding and driver only describe/support playback to
headphones and speakers, and capture from the external microphone, with
GPIO-based jack detection for the headphone jack only.
This driver is useful for the Venice2 board.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
From Nicolas Ferre:
AT91: Move to Common Clock Framework and sama5d3 implementation
This is the first step to move AT91 to the CCF.
- core CCF and drivers for most of the clocks
- use of CCF for sama5d3 (100% DT-based)
* tag 'at91-cleanup' of git://github.com/at91linux/linux-at91: (22 commits)
ARM: at91/dt: remove old clk material
ARM: at91: move sama5d3 SoC to common clk
ARM: at91/dt: define sama5d3xek's main clk frequency
ARM: at91/dt: define sama5d3 clocks
ARM: at91: prepare common clk transition for sama5d3 SoC
ARM: at91: prepare sama5 dt boards transition to common clk
ARM: at91: add new compatible strings for pmc driver
ARM: at91: move pit timer to common clk framework
dt: binding: add at91 clks dt bindings documentation
clk: at91: add PMC smd clock
clk: at91: add PMC usb clock
clk: at91: add PMC utmi clock
clk: at91: add PMC programmable clocks
clk: at91: add PMC peripheral clocks
clk: at91: add PMC system clocks
clk: at91: add PMC master clock
clk: at91: add PMC pll clocks
clk: at91: add PMC main clock
clk: at91: add PMC macro file for dt definitions
clk: at91: add PMC base support
...
Signed-off-by: Olof Johansson <olof@lixom.net>
Merging in post-rc1 fixes that have gone into rc2/3 to avoid later conflicts.
* commit 'fixes': (39 commits)
arm: dts: socfpga: Change some clocks of gate-clk type to perip-clk
arm: socfpga: Enable ARM_TWD for socfpga
ARM: multi_v7_defconfig: enable SDHCI_BCM_KONA and MMC_BLOCK_MINORS=16
ARM: sunxi_defconfig: enable NFS, TMPFS, PRINTK_TIME and nfsroot support
ARM: multi_v7_defconfig: enable network for BeagleBone Black
ARM: dts: Fix the name of supplies for smsc911x shared by OMAP
ARM: OMAP2+: Powerdomain: Fix unchecked dereference of arch_pwrdm
ARM: dts: omap3-beagle: Add omap-twl4030 audio support
ARM: dts: omap4-sdp: Fix pin muxing for wl12xx
ARM: dts: omap4-panda-common: Fix pin muxing for wl12xx
ARM: at91: fixed unresolved symbol "at91_pm_set_standby" when built without CONFIG_PM
ARM: at91: add usart3 alias to dtsi
ARM: at91: sama5d3: reduce TWI internal clock frequency
mmc: omap: Fix I2C dependency and make driver usable with device tree
mmc: omap: Fix DMA configuration to not rely on device id
ARM: dts: omap3-beagle: Fix USB host on beagle boards (for 3.13)
ARM: dts: omap3-igep0020: name twl4030 VPLL2 regulator as vdds_dsi
ARM: dts: AM33XX IGEP0033: add USB support
ARM: dts: AM33XX BASE0033: add 32KBit EEPROM support
ARM: dts: AM33XX BASE0033: add pinmux and user led support
...
Signed-off-by: Olof Johansson <olof@lixom.net>
Pull GPIO fixes from Linus Walleij:
"Here are a few more GPIO patches, we're a bit noisy for being the GPIO
subsystem, mostly due to the new descriptor API, but all is getting
into shape.
- Fix compile warnings
- Fix overly talkative diagnostic messages from usual use cases wrt
GPIO descriptors
- Add a documentation 00-INDEX
- Use platform GPIOs as fallback when ACPI or device tree is used as
the primary means to get GPIO lines
- A bug fix for the MPC8572/MPC8536 fixing erroneous input data"
* tag 'gpio-v3.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
gpiolib: change a warning to debug message when failing to get gpio
powerpc/gpio: Fix the wrong GPIO input data on MPC8572/MPC8536
gpiolib: use platform GPIO mappings as fallback
Documentation: gpiolib: add 00-INDEX file
gpiolib: fix lookup of platform-mapped GPIOs
gpiolib: add missing declarations
Pull ARM SoC fixes from Olof Johansson:
"Another batch of fixes for ARM SoCs for 3.13. The diffstat is large,
mostly because of:
- Another set of fixes to fix regressions caused by moving OMAP from
board files to DT. Tony thinks this was the last major set of
fixes, with maybe just a few small patches to follow.
- More fixes for Marvell platforms, most dealing with misdescribed
PCIe hardware, i.e. incorrect number of busses on some SoCs, etc.
The line delta adds up due to various ranges moving around when
this is fixed.
But there's also:
- Some smaller tweaks to defconfigs to make more boards bootable in
my test setup for better coverage.
- There are also a few other smaller fixes, a short series for at91,
a couple of reverts for ux500, etc"
* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (39 commits)
arm: dts: socfpga: Change some clocks of gate-clk type to perip-clk
arm: socfpga: Enable ARM_TWD for socfpga
ARM: multi_v7_defconfig: enable SDHCI_BCM_KONA and MMC_BLOCK_MINORS=16
ARM: sunxi_defconfig: enable NFS, TMPFS, PRINTK_TIME and nfsroot support
ARM: multi_v7_defconfig: enable network for BeagleBone Black
ARM: dts: Fix the name of supplies for smsc911x shared by OMAP
ARM: OMAP2+: Powerdomain: Fix unchecked dereference of arch_pwrdm
ARM: dts: omap3-beagle: Add omap-twl4030 audio support
ARM: dts: omap4-sdp: Fix pin muxing for wl12xx
ARM: dts: omap4-panda-common: Fix pin muxing for wl12xx
ARM: at91: fixed unresolved symbol "at91_pm_set_standby" when built without CONFIG_PM
ARM: at91: add usart3 alias to dtsi
ARM: at91: sama5d3: reduce TWI internal clock frequency
mmc: omap: Fix I2C dependency and make driver usable with device tree
mmc: omap: Fix DMA configuration to not rely on device id
ARM: dts: omap3-beagle: Fix USB host on beagle boards (for 3.13)
ARM: dts: omap3-igep0020: name twl4030 VPLL2 regulator as vdds_dsi
ARM: dts: AM33XX IGEP0033: add USB support
ARM: dts: AM33XX BASE0033: add 32KBit EEPROM support
ARM: dts: AM33XX BASE0033: add pinmux and user led support
...
This moves the External Bus Interface (EBI) over to a device
tree node and deletes the static mappings from the platform.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This patch changes the cpufreq-cpu0 driver to consider if
a cpu needs cooling (with cpufreq). In case the cooling is needed,
the cpu0 device tree node needs to be properly configured
with cooling device properties.
In case these properties are present,, the driver will
load a cpufreq cooling device in the system. The cpufreq-cpu0
driver is not interested in determining how the system should
be using the cooling device. The driver is responsible
only of loading the cooling device.
Describing how the cooling device will be used can be
accomplished by setting up a thermal zone that references
and is composed by the cpufreq cooling device.
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <rob.herring@calxeda.com>
Cc: cpufreq@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: devicetree-discuss@lists.ozlabs.org
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
This patch introduces a device tree bindings for
describing the hardware thermal behavior and limits.
Also a parser to read and interpret the data and feed
it in the thermal framework is presented.
This patch introduces a thermal data parser for device
tree. The parsed data is used to build thermal zones
and thermal binding parameters. The output data
can then be used to deploy thermal policies.
This patch adds also documentation regarding this
API and how to define tree nodes to use
this infrastructure.
Note that, in order to be able to have control
on the sensor registration on the DT thermal zone,
it was required to allow changing the thermal zone
.get_temp callback. For this reason, this patch
also removes the 'const' modifier from the .ops
field of thermal zone devices.
Cc: Zhang Rui <rui.zhang@intel.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Enable common clock driver of Hi3620 SoC. clkgate-seperated driver is
used to support the clock gate that enable/disable/status registers
are seperated.
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
This patch adds device tree support to the PXA's PWM driver. Nothing
needs to be extracted from the device tree node by the PWM device.
Client devices need only specify the period; the per-chip index is
implicitly zero because one device node must be present for each PWM
output in use. This approach is more convenient due to the wide
variability in the number of PWM channels present across the various PXA
variants, and is made possible by the fact that the register sets for
each PWM channel are segregated from each other. An of_xlate() method
is added to parse this single-cell node. The existing ID table is
reused for the match table data.
Tested on a Palm Treo 680 (both platform data and DT cases).
Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
From Linus Walleij:
Ux500 device tree patches for v3.14, take one:
- Fix up tc3589x bindings so this chip works again.
- Remove SSP platform devices, as we now boot from device tree
exclusively.
- Delete surplus AB8500/DB8500 platform data, not obtained from
the device tree.
- Add DMA config for the MSP devices.
- A series of 21 patches moving pin control config for the
on-chip Nomadik pin controller from the board file
to the device tree, step by step.
- Two patches to the STE DMA40 driver regarding the high-prio
DMA channel so this can be moved to the device tree. Both have
Vinod's ACK.
- Decommission of the non-device tree boot path for the timer
initialization code.
- Deletion of the non-devicetree probe path from the MTU timer
driver, as all platforms using it are now using device tree.
This has Daniel Lezcano's ACK.
* tag 'ux500-devicetree-v3.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-stericsson: (39 commits)
ARM: ux500: decomission custom SMP TWD timer init
clksrc: delete nomadik MTU non-DT boot path
ARM: ux500: decomission the non-DT MTU init sequence
dma: ste_dma40: Parse flags property for new 'high priority channel' request
dma: ste_dma40: Expand DT binding to accept 'high-priority channel' flag
ARM: ux500: Remove checking for DT during timer init
ARM: ux500: Clean-up legacy extern prototype
ARM: ux500: Remove unused call to register AMBA devices
ARM: ux500: Clean-up non-DT IRQ initialisation
pinctrl: nomadik: decomission non-DT boot path
pinctrl: nomadik: move platform data handling into driver
ARM: ux500: get rid of unused header
ARM: ux500: delete Nomadik pinctrl AUXDATA
ARM: ux500: delete remnant pin config macros
ARM: ux500: move snowball pin configs to device tree
ARM: ux500: move snowball LED pin control to device tree
ARM: ux500: convert Snowball SPI pin reference
ARM: ux500: move snowball ethernet config to device tree
ARM: ux500: move HREFv60plus pin configs to device tree
ARM: ux500: move final HREFv60 LCD pins to device tree
...
Signed-off-by: Olof Johansson <olof@lixom.net>
From Tony Lindgren:
Some omap related fixes that have come up with people moving to device
tree only based booting for omap2+.
The series contains a handful of fixes for the igep boards as they were
one of the first omap3 boards to jump over completely to device tree
based booting. So these can be considered regressions compared to
booting igep in legacy mode with board files in v3.12.
Also included are few other device tree vs legacy booting regressions:
- yet more missing omap3 .dtsi entries that have showed up booting
various boards with device tree only
- n900 eMMC device tree fix
- fixes for beagle USB EHCI
- two fixes to make omap2420 MMC work
As we're moving omap2+ to be device tree only for v3.14, I'd like to
have v3.13 work equally well for legacy based booting and device tree
based booting. So there will be likely few more device tree related
booting patches trickling in.
This series also includes a regression fix for the omap timer posted
mode that may wrongly stay on from the bootloader for some SoCs.
* tag 'omap-for-v3.13/fixes-against-rc1-take2' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
mmc: omap: Fix I2C dependency and make driver usable with device tree
mmc: omap: Fix DMA configuration to not rely on device id
ARM: dts: omap3-beagle: Fix USB host on beagle boards (for 3.13)
ARM: dts: omap3-igep0020: name twl4030 VPLL2 regulator as vdds_dsi
ARM: dts: AM33XX IGEP0033: add USB support
ARM: dts: AM33XX BASE0033: add 32KBit EEPROM support
ARM: dts: AM33XX BASE0033: add pinmux and user led support
ARM: dts: AM33XX BASE0033: add pinmux and hdmi node to enable display
ARM: dts: omap3-igep0020: Add pinmuxing for DVI output
ARM: dts: omap3-igep0020: Add pinmux setup for i2c devices
ARM: dts: omap3-igep: Update to use the TI AM/DM37x processor
ARM: dts: omap3-igep: Add support for LBEE1USJYC WiFi connected to SDIO
ARM: dts: omap3-igep: Fix bus-width for mmc1
ARM: OMAP2+: dss-common: change IGEP's DVI DDC i2c bus
ARM: OMAP2+: Disable POSTED mode for errata i103 and i767
ARM: OMAP2+: Fix eMMC on n900 with device tree
ARM: OMAP2+: Add fixed regulator to omap2plus_defconfig
ARM: OMAP2+: Fix more missing data for omap3.dtsi file
Signed-off-by: Olof Johansson <olof@lixom.net>
There are already humidity sensors in the hwmon subsystem,
so we use their unit (milli percent) here as well.
Signed-off-by: Harald Geyer <harald@ccbib.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This adds a very simplistic driver to utilize the CSI2A interface inside
the ISS subsystem in OMAP4, and dump the data to memory.
Check Documentation/video4linux/omap4_camera.txt for details.
This commit adds the driver core, registers definitions and
documentation.
Signed-off-by: Sergio Aguirre <sergio.a.aguirre@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Traditionally the "get" functions increment the reference count of the
object that is returned, which does not happen with vme_slot_get. The
function vme_slot_get returns the physical VME slot associated with a
particular struct vme_dev. Rename vme_slot_num to avoid any confusion.
Signed-off-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The match function for vme_user is completely wrong. It will blindly bind
against the first VME slot on each bus (at this point that would be just the
first bus as the driver can only handle one bus).
The original intention (before some major subsystem changes) was that the
driver bind against the slot to which the bridge was attached in the VME
system and to the bus(es) provided via the "bus" module parameter.
To do this cleanly (i.e. without poking arround in the subsystems internal
stuctures) a functionality has been added to provide access to the bus
enumeration.
Signed-off-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Dave Jones got the following lockdep splat:
> ======================================================
> [ INFO: possible circular locking dependency detected ]
> 3.12.0-rc3+ #92 Not tainted
> -------------------------------------------------------
> trinity-child2/15191 is trying to acquire lock:
> (&rdp->nocb_wq){......}, at: [<ffffffff8108ff43>] __wake_up+0x23/0x50
>
> but task is already holding lock:
> (&ctx->lock){-.-...}, at: [<ffffffff81154c19>] perf_event_exit_task+0x109/0x230
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
>
> -> #3 (&ctx->lock){-.-...}:
> [<ffffffff810cc243>] lock_acquire+0x93/0x200
> [<ffffffff81733f90>] _raw_spin_lock+0x40/0x80
> [<ffffffff811500ff>] __perf_event_task_sched_out+0x2df/0x5e0
> [<ffffffff81091b83>] perf_event_task_sched_out+0x93/0xa0
> [<ffffffff81732052>] __schedule+0x1d2/0xa20
> [<ffffffff81732f30>] preempt_schedule_irq+0x50/0xb0
> [<ffffffff817352b6>] retint_kernel+0x26/0x30
> [<ffffffff813eed04>] tty_flip_buffer_push+0x34/0x50
> [<ffffffff813f0504>] pty_write+0x54/0x60
> [<ffffffff813e900d>] n_tty_write+0x32d/0x4e0
> [<ffffffff813e5838>] tty_write+0x158/0x2d0
> [<ffffffff811c4850>] vfs_write+0xc0/0x1f0
> [<ffffffff811c52cc>] SyS_write+0x4c/0xa0
> [<ffffffff8173d4e4>] tracesys+0xdd/0xe2
>
> -> #2 (&rq->lock){-.-.-.}:
> [<ffffffff810cc243>] lock_acquire+0x93/0x200
> [<ffffffff81733f90>] _raw_spin_lock+0x40/0x80
> [<ffffffff810980b2>] wake_up_new_task+0xc2/0x2e0
> [<ffffffff81054336>] do_fork+0x126/0x460
> [<ffffffff81054696>] kernel_thread+0x26/0x30
> [<ffffffff8171ff93>] rest_init+0x23/0x140
> [<ffffffff81ee1e4b>] start_kernel+0x3f6/0x403
> [<ffffffff81ee1571>] x86_64_start_reservations+0x2a/0x2c
> [<ffffffff81ee1664>] x86_64_start_kernel+0xf1/0xf4
>
> -> #1 (&p->pi_lock){-.-.-.}:
> [<ffffffff810cc243>] lock_acquire+0x93/0x200
> [<ffffffff8173419b>] _raw_spin_lock_irqsave+0x4b/0x90
> [<ffffffff810979d1>] try_to_wake_up+0x31/0x350
> [<ffffffff81097d62>] default_wake_function+0x12/0x20
> [<ffffffff81084af8>] autoremove_wake_function+0x18/0x40
> [<ffffffff8108ea38>] __wake_up_common+0x58/0x90
> [<ffffffff8108ff59>] __wake_up+0x39/0x50
> [<ffffffff8110d4f8>] __call_rcu_nocb_enqueue+0xa8/0xc0
> [<ffffffff81111450>] __call_rcu+0x140/0x820
> [<ffffffff81111b8d>] call_rcu+0x1d/0x20
> [<ffffffff81093697>] cpu_attach_domain+0x287/0x360
> [<ffffffff81099d7e>] build_sched_domains+0xe5e/0x10a0
> [<ffffffff81efa7fc>] sched_init_smp+0x3b7/0x47a
> [<ffffffff81ee1f4e>] kernel_init_freeable+0xf6/0x202
> [<ffffffff817200be>] kernel_init+0xe/0x190
> [<ffffffff8173d22c>] ret_from_fork+0x7c/0xb0
>
> -> #0 (&rdp->nocb_wq){......}:
> [<ffffffff810cb7ca>] __lock_acquire+0x191a/0x1be0
> [<ffffffff810cc243>] lock_acquire+0x93/0x200
> [<ffffffff8173419b>] _raw_spin_lock_irqsave+0x4b/0x90
> [<ffffffff8108ff43>] __wake_up+0x23/0x50
> [<ffffffff8110d4f8>] __call_rcu_nocb_enqueue+0xa8/0xc0
> [<ffffffff81111450>] __call_rcu+0x140/0x820
> [<ffffffff81111bb0>] kfree_call_rcu+0x20/0x30
> [<ffffffff81149abf>] put_ctx+0x4f/0x70
> [<ffffffff81154c3e>] perf_event_exit_task+0x12e/0x230
> [<ffffffff81056b8d>] do_exit+0x30d/0xcc0
> [<ffffffff8105893c>] do_group_exit+0x4c/0xc0
> [<ffffffff810589c4>] SyS_exit_group+0x14/0x20
> [<ffffffff8173d4e4>] tracesys+0xdd/0xe2
>
> other info that might help us debug this:
>
> Chain exists of:
> &rdp->nocb_wq --> &rq->lock --> &ctx->lock
>
> Possible unsafe locking scenario:
>
> CPU0 CPU1
> ---- ----
> lock(&ctx->lock);
> lock(&rq->lock);
> lock(&ctx->lock);
> lock(&rdp->nocb_wq);
>
> *** DEADLOCK ***
>
> 1 lock held by trinity-child2/15191:
> #0: (&ctx->lock){-.-...}, at: [<ffffffff81154c19>] perf_event_exit_task+0x109/0x230
>
> stack backtrace:
> CPU: 2 PID: 15191 Comm: trinity-child2 Not tainted 3.12.0-rc3+ #92
> ffffffff82565b70 ffff880070c2dbf8 ffffffff8172a363 ffffffff824edf40
> ffff880070c2dc38 ffffffff81726741 ffff880070c2dc90 ffff88022383b1c0
> ffff88022383aac0 0000000000000000 ffff88022383b188 ffff88022383b1c0
> Call Trace:
> [<ffffffff8172a363>] dump_stack+0x4e/0x82
> [<ffffffff81726741>] print_circular_bug+0x200/0x20f
> [<ffffffff810cb7ca>] __lock_acquire+0x191a/0x1be0
> [<ffffffff810c6439>] ? get_lock_stats+0x19/0x60
> [<ffffffff8100b2f4>] ? native_sched_clock+0x24/0x80
> [<ffffffff810cc243>] lock_acquire+0x93/0x200
> [<ffffffff8108ff43>] ? __wake_up+0x23/0x50
> [<ffffffff8173419b>] _raw_spin_lock_irqsave+0x4b/0x90
> [<ffffffff8108ff43>] ? __wake_up+0x23/0x50
> [<ffffffff8108ff43>] __wake_up+0x23/0x50
> [<ffffffff8110d4f8>] __call_rcu_nocb_enqueue+0xa8/0xc0
> [<ffffffff81111450>] __call_rcu+0x140/0x820
> [<ffffffff8109bc8f>] ? local_clock+0x3f/0x50
> [<ffffffff81111bb0>] kfree_call_rcu+0x20/0x30
> [<ffffffff81149abf>] put_ctx+0x4f/0x70
> [<ffffffff81154c3e>] perf_event_exit_task+0x12e/0x230
> [<ffffffff81056b8d>] do_exit+0x30d/0xcc0
> [<ffffffff810c9af5>] ? trace_hardirqs_on_caller+0x115/0x1e0
> [<ffffffff810c9bcd>] ? trace_hardirqs_on+0xd/0x10
> [<ffffffff8105893c>] do_group_exit+0x4c/0xc0
> [<ffffffff810589c4>] SyS_exit_group+0x14/0x20
> [<ffffffff8173d4e4>] tracesys+0xdd/0xe2
The underlying problem is that perf is invoking call_rcu() with the
scheduler locks held, but in NOCB mode, call_rcu() will with high
probability invoke the scheduler -- which just might want to use its
locks. The reason that call_rcu() needs to invoke the scheduler is
to wake up the corresponding rcuo callback-offload kthread, which
does the job of starting up a grace period and invoking the callbacks
afterwards.
One solution (championed on a related problem by Lai Jiangshan) is to
simply defer the wakeup to some point where scheduler locks are no longer
held. Since we don't want to unnecessarily incur the cost of such
deferral, the task before us is threefold:
1. Determine when it is likely that a relevant scheduler lock is held.
2. Defer the wakeup in such cases.
3. Ensure that all deferred wakeups eventually happen, preferably
sooner rather than later.
We use irqs_disabled_flags() as a proxy for relevant scheduler locks
being held. This works because the relevant locks are always acquired
with interrupts disabled. We may defer more often than needed, but that
is at least safe.
The wakeup deferral is tracked via a new field in the per-CPU and
per-RCU-flavor rcu_data structure, namely ->nocb_defer_wakeup.
This flag is checked by the RCU core processing. The __rcu_pending()
function now checks this flag, which causes rcu_check_callbacks()
to initiate RCU core processing at each scheduling-clock interrupt
where this flag is set. Of course this is not sufficient because
scheduling-clock interrupts are often turned off (the things we used to
be able to count on!). So the flags are also checked on entry to any
state that RCU considers to be idle, which includes both NO_HZ_IDLE idle
state and NO_HZ_FULL user-mode-execution state.
This approach should allow call_rcu() to be invoked regardless of what
locks you might be holding, the key word being "should".
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
This commit replaces full barriers by targeted use of load-acquire and
store-release.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Restore comments as suggested by David Howells. ]
The code sample in Documentation/circular-buffers.txt appears to have a
few ordering bugs. This patch therefore applies the needed fixes.
Reported-by: Lech Fomicki <lfomicki@poczta.fm>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
The DWC2 USB controller in the BCM2835 (Raspberry Pi) needs some non-
default parameters. Select these based on the compatible value from the
DT node. For all other HW, fall back to the default parameters currently
in use.
The values in params_bcm2835[] were posted to the mailing list by Paul
quite some time ago. I made a couple of minor modifications since then;
to set ahbcfg instead of ahb_single, and to set uframe_sched.
Signed-off-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Give a short overview of the various GPIO documentation files.
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
The r8a7791 (R-Car M2) has a GPIO controller with additional features
compared to the generic renesas,gpio-rcar compatible devices. Add a
model-specific string to let the driver enable these features.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This binding shouldn't exist; Tegra20 has two forms of SPI controller
that are documented separately in nvidia,tegra20-sflash.txt and
nvidia,tegra20-slink.txt.
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
phy-supply is an optional property of the fec driver, so add it to the binding
documentation.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
The binding and support for omap5-mpu which has a cortex-a15
smp core, gic and integrated L2 cache has been existing for sometime.
So Documenting the missing binding here.
Cc: Benoit Cousson <bcousson@baylibre.com>
Signed-off-by: Sricharan R <r.sricharan@ti.com>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
