When debugging a recent lockup bug i found various deficiencies
in how our current lockup detection helpers work:
- SysRq-L is not very efficient as it uses a workqueue, hence
it cannot punch through hard lockups and cannot see through
most soft lockups either.
- The SysRq-L code depends on the NMI watchdog - which is off
by default.
- We dont print backtraces from the RCU code's built-in
'RCU state machine is stuck' debug code. This debug
code tends to be one of the first (and only) mechanisms
that show that a lockup has occured.
This patch changes the code so taht we:
- Trigger the NMI backtrace code from SysRq-L instead of using
a workqueue (which cannot punch through hard lockups)
- Trigger print-all-CPU-backtraces from the RCU lockup detection
code
Also decouple the backtrace printing code from the NMI watchdog:
- Dont use variable size cpumasks (it might not be initialized
and they are a bit more fragile anyway)
- Trigger an NMI immediately via an IPI, instead of waiting
for the NMI tick to occur. This is a lot faster and can
produce more relevant backtraces. It will also work if the
NMI watchdog is disabled.
- Dont print the 'dazed and confused' message when we print
a backtrace from the NMI
- Do a show_regs() plus a dump_stack() to get maximum info
out of the dump. Worst-case we get two stacktraces - which
is not a big deal. Sometimes, if register content is
corrupted, the precise stack walker in show_regs() wont
give us a full backtrace - in this case dump_stack() will
do it.
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
SPI pins are now allocated in pcm037.c, remove them from EET.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Changeset 3869c4aa18
that went in after 2.6.30-rc1 was a seemingly small change to _set_memory_wc()
to make it complaint with SDM requirements. But, introduced a nasty bug, which
can result in crash and/or strange corruptions when set_memory_wc is used.
One such crash reported here
http://lkml.org/lkml/2009/7/30/94
Actually, that changeset introduced two bugs.
* change_page_attr_set() takes &addr as first argument and can the addr value
might have changed on return, even for single page change_page_attr_set()
call. That will make the second change_page_attr_set() in this routine
operate on unrelated addr, that can eventually cause strange corruptions
and bad page state crash.
* The second change_page_attr_set() call, before setting _PAGE_CACHE_WC, should
clear the earlier _PAGE_CACHE_UC_MINUS, as otherwise cache attribute will not
be WC (will be UC instead).
The patch below fixes both these problems. Sending a single patch to fix both
the problems, as the change is to the same line of code. The change to have a
addr_copy is not very clean. But, it is simpler than making more changes
through various routines in pageattr.c.
A huge thanks to Jerome for reporting this problem and providing a simple test
case that helped us root cause the problem.
Reported-by: Jerome Glisse <glisse@freedesktop.org>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20090730214319.GA1889@linux-os.sc.intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx:
dmaengine: at_hdmac: add DMA slave transfers
dmaengine: at_hdmac: new driver for the Atmel AHB DMA Controller
dmaengine: dmatest: correct thread_count while using multiple thread per channel
dmaengine: dmatest: add a maximum number of test iterations
drivers/dma: Remove unnecessary semicolons
drivers/dma/fsldma.c: Remove unnecessary semicolons
dmaengine: move HIGHMEM64G restriction to ASYNC_TX_DMA
fsldma: do not clear bandwidth control bits on the 83xx controller
fsldma: enable external start for the 83xx controller
fsldma: use PCI Read Multiple command
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc: Update defconfigs for embedded 6xx/7xxx, 8xx, 8{3,5,6}xxx
powerpc/86xx: Update GE Fanuc sbc310 default configuration
powerpc/86xx: Update defconfig for GE Fanuc's PPC9A
cpm_uart: Don't use alloc_bootmem in cpm_uart_cpm2.c
powerpc/83xx: Fix PCI IO base address on MPC837xE-RDB boards
powerpc/85xx: Don't scan for TBI PHY addresses on MPC8569E-MDS boards
powerpc/85xx: Fix ethernet link detection on MPC8569E-MDS boards
powerpc/mm: Fix SMP issue with MMU context handling code
The s3c64xx devices use the same hardware core as s3c24xx, so move
the timer/pwm handling to plat-s3c so it can be used by both.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Move the s3c_device_nand platform device from plat-s3c24xx to plat-s3c,
now that the nand driver also support the s3c64xx devices.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add support for the Airgoo HMT (home media terminal) device.
The HMT is a tablet device with a s3c6410, a 7" LCD and a number
of peripheral connections.
For more details of the hardware specs, see:
http://article.gmane.org/gmane.linux.debian.devel.embedded/4307
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
[ben-linux@fluff.org: subject rewrite]
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
The pwm hardware only checks the compare register after a decrement,
so the pin never toggles if tcmp = tcnt.
This happens when a very low duty cycle is requested. Fix it by always
ensuring that tcmp < tcnt.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add debugfs support for the cpufreq driver to allow
information about the system state to be exported to
the user.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add armclk for use with the cpufreq support and anything
else that may want it. This clock is just a direct
descendant of fclk.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add board support for CPUFREQ with the Simtec BAST board
registering the necessary information with the core.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add a sysdev S3C2410A sysdev to allow the differentiation
of the S3C2410A from the S3C2410. This is needed for the
CPUFREQ code to enable the extra features and update cpu
specific information.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Update the mapping of the memory controler registers and
add the missing definitions of the register block for the
SSMC.
The register contents definitions can be found in the pl093
header.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Currently map-base.h defines the main virtual address mappings made
for all the support S3C SoC series, but does not then define any base
for per-cpu mappings to be made from.
Add S3C_ADDR_CPU() macro to define an virtual address as an offset
from the last of the core mappings.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add entries to select the crystal to select for each different
supported board. This information is then available for anything
else requiring this, such as the CPUFreq PLL tables.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add io-timing support for frequency scaling on the S3C2410 SoC.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add the S3C24XX to the main ARM CPUFreq Kconfig support list.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add ARCH_HAS_CPUFREQ so that each machine config can select
it if they have CPUFREQ driver support. This means that the
CPUFREQ specific area does not need the if statement updating
each time a new machine is added.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Move the structure s3c_cpufreq_config from cpu-freq.h to the
less advertised cpu-freq-core.h as it is not needed by anything
outside the core drivers.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Update arch/arm/plat-s3c/include/plat/cpu-freq.h to include kerneldoc
style documentation.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add the core of the support for enabling the CPUFreq driver on
all S3C24XX based systems.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Add definitions and an accessor macro to deal with
reading bus information from S3C2410_BWSCON for any
given numbered bank.
Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
CPUAT91 is based on Atmel's AT91RM9200 with up to 16MB Strataflash,
up to 128MB SDRAM and an ethernet PHY in RMII mode.
Signed-off-by: Eric Benard <ebenard@eukrea.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
CPU9260 and CPU9G20 share the same PCB populated with either
Atmel's AT91SAM9260B or AT91SAM9G20B with up to 64MB Strataflash,
up to 128MB SDRAM, up to 2GB NAND and an ethernet PHY in RMII mode.
Signed-off-by: Eric Benard <eric@eukrea.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The EP93xx features two PWMs (one on the EP9307) with the following
features:
* Configurable dual output
* Separate input clocks for each PWM output
* 16-bit resolution
* Programmable pulse width (duty cycle), interval (frequency), and
polarity
This adds the necessary core support as well as the driver. A sysfs
interface is provided to control the PWM outputs.
Signed-off-by: Matthieu Crapet <mcrapet@gmail.com>
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
After ftrace_trace_function is called r1 is probably clobbered so don't
try to use its value for restoring.
This was introduced in v2.6.29~38^2~7
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Every so often, after code shuffles, I need to go through and unbitrot
the Lguest Journey (see drivers/lguest/README). Since we now use RCU in
a simple form in one place I took the opportunity to expand that explanation.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
I don't really notice it (except to begrudge the extra vertical
space), but Ingo does. And he pointed out that one excuse of lguest
is as a teaching tool, it should set a good example.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
General update of defconfig including the following notable changes:
- Enable Highmem support.
- Support for PCMCIA based daughter card.
Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
