per_cpu(processors, n) can be NULL, resulting in:
Loading CPUFreq modules[ 437.661360] BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffffa0434314>] pcc_cpufreq_cpu_init+0x74/0x220 [pcc_cpufreq]
It's better to avoid the oops by failing the driver, and allowing the
system to boot.
Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Len Brown <lenb@kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'drm-core-next' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (135 commits)
drm/radeon/kms: fix DP training for DPEncoderService revision bigger than 1.1
drm/radeon/kms: add missing vddci setting on NI+
drm/radeon: Add a rmb() in IH processing
drm/radeon: ATOM Endian fix for atombios_crtc_program_pll()
drm/radeon: Fix the definition of RADEON_BUF_SWAP_32BIT
drm/radeon: Do an MMIO read on interrupts when not uisng MSIs
drm/radeon: Writeback endian fixes
drm/radeon: Remove a bunch of useless _iomem casts
drm/gem: add support for private objects
DRM: clean up and document parsing of video= parameter
DRM: Radeon: Fix section mismatch.
drm: really make debug levels match in edid failure code
drm/radeon/kms: fix i2c map for rv250/280
drm/nouveau/gr: disable fifo access and idle before suspend ctx unload
drm/nouveau: pass flag to engine fini() method on suspend
drm/nouveau: replace nv04_graph_fifo_access() use with direct reg bashing
drm/nv40/gr: rewrite/split context takedown functions
drm/nouveau: detect disabled device in irq handler and return IRQ_NONE
drm/nouveau: ignore connector type when deciding digital/analog on DVI-I
drm/nouveau: Add a quirk for Gigabyte NX86T
...
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (99 commits)
drivers/virt: add missing linux/interrupt.h to fsl_hypervisor.c
powerpc/85xx: fix mpic configuration in CAMP mode
powerpc: Copy back TIF flags on return from softirq stack
powerpc/64: Make server perfmon only built on ppc64 server devices
powerpc/pseries: Fix hvc_vio.c build due to recent changes
powerpc: Exporting boot_cpuid_phys
powerpc: Add CFAR to oops output
hvc_console: Add kdb support
powerpc/pseries: Fix hvterm_raw_get_chars to accept < 16 chars, fixing xmon
powerpc/irq: Quieten irq mapping printks
powerpc: Enable lockup and hung task detectors in pseries and ppc64 defeconfigs
powerpc: Add mpt2sas driver to pseries and ppc64 defconfig
powerpc: Disable IRQs off tracer in ppc64 defconfig
powerpc: Sync pseries and ppc64 defconfigs
powerpc/pseries/hvconsole: Fix dropped console output
hvc_console: Improve tty/console put_chars handling
powerpc/kdump: Fix timeout in crash_kexec_wait_realmode
powerpc/mm: Fix output of total_ram.
powerpc/cpufreq: Add cpufreq driver for Momentum Maple boards
powerpc: Correct annotations of pmu registration functions
...
Fix up trivial Kconfig/Makefile conflicts in arch/powerpc, drivers, and
drivers/cpufreq
Add simple cpufreq driver for Maple-based boards (ppc970fx evaluation
kit and others). Driver is based on a cpufreq driver for 64-bit powermac
boxes with all pmac-dependant features removed and simple cleanup
applied.
Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* 'drm-intel-next' of ssh://master.kernel.org/pub/scm/linux/kernel/git/keithp/linux-2.6: (52 commits)
drm/i915: provide module parameter description
drm/i915: add module parameter compiler hints
drm/i915/bios: Avoid temporary allocation whilst searching for downclock
drm/i915: Cache GT fifo count for SandyBridge
i915: Fix opregion notifications
drm/i915: TVDAC_STATE_CHG does not indicate successful load-detect
drm/i915: Select correct pipe during TV detect
drm/i915/ringbuffer: Idling requires waiting for the ring to be empty
Revert "drm/i915: enable rc6 by default"
drm/i915: Clean up i915_driver_load failure path
drm/i915: Enable i915 frame buffer compression by default
drm/i915: Share the common work of disabling active FBC before updating
drm/i915: Perform intel_enable_fbc() from a delayed task
drm/i915: Disable FBC across page-flipping
drm/i915: Set persistent-mode for ILK/SNB framebuffer compression
drm/i915: Use of a CPU fence is mandatory to update FBC regions upon CPU writes
drm/i915: Remove vestigial pitch from post-gen2 FBC control routines
drm/i915: Replace direct calls to vfunc.disable_fbc with intel_disable_fbc()
drm/i915: Only export the generic intel_disable_fbc() interface
drm/i915: Enable GPU reset on Ivybridge.
...
The following symbols are needlessly defined global:
s5pv210_verify_speed
s5pv210_getspeed
Make them static.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
The following symbols are needlessly defined global:
exynos4_verify_speed
exynos4_getspeed
exynos4_set_clkdiv
Make them static.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
By extension from the 667MHz based clocks currently supported add 100MHz
and 200MHz operating points. Due to a lack of documentation these have not
been confirmed as supported but by extension from the existing frequencies
they should be OK, and I've given them quite a bit of runtime testing.
The major risk is synchronization with the non-ARM clocks but as we
can't currently scale the ARM PLL the risk should be relatively low.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
When system reboot, the CPUFREQ level should be 800MHz to prevent
system lockup.
Signed-off-by: Huisung Kang <hs1218.kang@samsung.com>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Voltage scaling accesses the MAX8998 regulators over bit-banged I2C
with lots of udelays. In the case of decreasing CPU speed, the
number of loops per us for udelay needs to be adjusted prior to
decreasing voltage to avoid delaying for up to 10X too long.
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Without this lock the call to change the frequency for suspend could
switch to a new frequency while another thread was still changing the
cpu voltage.
Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Minimum 800MHz is needed to enter/exit suspend mode due to voltage mismatch.
Signed-off-by: Huisung Kang <hs1218.kang@samsung.com>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Relation has an additional symantics other than standard.
s5pv310_target funtion have below additional relation.
- DISABLE_FURTHER_CPUFREQ : disable further access to target
- ENABLE_FURTHER_CPUFRER : enable access to target
Signed-off-by: Huisung Kang <hs1218.kang@samsung.com>
Signed-off-by: Jonghwan Choi <jhbird.choi@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
The CPUFREQ_POSTCHANGE notification is used to update things that depend on
the system clock rates. Since this may include the interfaces used to talk
to the regulators do the notification before we try to update regulators
to reflect lowered system clock rate.
The voltage scaling is just a power optimisation and may not happen at all
so there's no concern about it not having completed.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
At least some newer S3C6410 silicon supports operation up to 800MHz rather
than just 667MHz. Unfortunately I don't have access to any of documentation
of this other than some running systems, add a new cpufreq table entry for
this based on the behaviour of those systems.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
The successive calls to clk_get each call clk_put in the case of failure,
but this is not done for subsequent error handling code. The calls to
clk_get are moved to the end of the function, and appropriate gotos are
added.
A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)
// <smpl>
@r exists@
expression e1,e2;
statement S;
@@
e1 = clk_get@p1(...);
... when != e1 = e2
when != clk_put(e1)
when any
if (...) { ... when != clk_put(e1)
when != if (...) { ... clk_put(e1) ... }
* return@p3 ...;
} else S
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
According to discussion of the ARM arch subsystem migration,
ARM cpufreq drivers move to drivers/cpufreq. So this patch
adds Kconfig.arm for ARM like x86 and adds Samsung S5PV210
and EXYNOS4210 cpufreq driver compile in there.
As a note, otherw will be moved.
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Dave Jones <davej@redhat.com>
This is a straight code motion patch, there are no changes to the driver
itself. The Kconfig is left untouched as the ARM CPUfreq Kconfig is all
in one big block in arm/Kconfig and should be moved en masse rather than
being done piecemeal.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Dave Jones <davej@redhat.com>
acpi-cpufreq checks each CPU for aperf/mperf support, but only sets a
global flag. This will cause errors if some CPUs in the system don't
support the feature. Check boot_cpu_has() instead in order to make sure
that all CPUs support it.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Dave Jones <davej@redhat.com>
I came across a memory leak during a cyclic cpu-online-offline test.
Signed-off-by: Yu Luming <luming.yu@intel.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Jones <davej@redhat.com>
This allows drivers and other code to get the max reported CPU frequency.
Initial use is for scaling ring frequency with GPU frequency in the i915
driver.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Keith Packard <keithp@keithp.com>
This patch augments the pstate transition code to error out
(instead of returning 0) when an incorrect pstate is provided.
Suggested-by: Borislav Petkov <bp@alien8.de>
CC: andre.przywara@amd.com
CC: Mark.Langsdorf@amd.com
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Before this patch if we failed the vid transition would still try to
submit the "new" frequencies to cpufreq.
That is incorrect - also we could submit a non-existing frequency value
which would cause cpufreq to crash. The ultimate fix is in cpufreq
to deal with incorrect values, but this patch improves the error
recovery in the AMD powernowk8 driver.
The failure that was reported was as follows:
powernow-k8: Found 1 AMD Athlon(tm) 64 Processor 3700+ (1 cpu cores) (version 2.20.00)
powernow-k8: fid 0x2 (1000 MHz), vid 0x12
powernow-k8: fid 0xa (1800 MHz), vid 0xa
powernow-k8: fid 0xc (2000 MHz), vid 0x8
powernow-k8: fid 0xe (2200 MHz), vid 0x8
Marking TSC unstable due to cpufreq changes
powernow-k8: fid trans failed, fid 0x2, curr 0x0
BUG: unable to handle kernel paging request at ffff880807e07b78
IP: [<ffffffff81479163>] cpufreq_stats_update+0x46/0x5b
...
And transition fails and data->currfid ends up with 0. Since
the machine does not support 800Mhz value when the calculation is
done ('find_khz_freq_from_fid(data->currfid);') it reports the
new frequency as 800000 which is bogus. This patch fixes
the issue during target setting.
The patch however does not fix the issue in 'powernowk8_cpu_init'
where the pol->cur can also be set with the 800000 value:
pol->cur = find_khz_freq_from_fid(data->currfid);
dprintk("policy current frequency %d kHz\n", pol->cur);
/* min/max the cpu is capable of */
if (cpufreq_frequency_table_cpuinfo(pol, data->powernow_table)) {
The fix for that looks to update cpufreq_frequency_table_cpuinfo to
check pol->cur.... but that would cause an regression in how the
acpi-cpufreq driver works (it sets cpu->cur after calling
cpufreq_frequency_table_cpuinfo). Instead the fix will be to let
cpufreq gracefully handle bogus data (another patch).
Acked-by: Borislav Petkov <bp@alien8.de>
CC: andre.przywara@amd.com
CC: Mark.Langsdorf@amd.com
Reported-by: Tobias Diedrich <ranma+xen@tdiedrich.de>
Tested-by: Tobias Diedrich <ranma+xen@tdiedrich.de>
[v1: Rebased on v3.0-rc2, reduced patch to deal with vid case]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Dave Jones <davej@redhat.com>
If the driver submitted an non-existing pol>cur value (say it
used the default initialized value of zero), when the cpufreq
stats tries to setup its initial values it incorrectly sets
stat->last_index to -1 (or 0xfffff...). And cpufreq_stats_update
tries to update at that index location and fails.
This can be caused by:
stat->last_index = freq_table_get_index(stat, policy->cur);
not finding the appropiate frequency in the table (b/c the policy->cur
is wrong) and we end up crashing. The fix however is
concentrated in the 'cpufreq_stats_update' as the last_index
(and old_index) are updated there. Which means it can reset
the last_index to -1 again and on the next iteration cause a crash.
Without this patch, the following crash is observed:
powernow-k8: Found 1 AMD Athlon(tm) 64 Processor 3700+ (1 cpu cores) (version 2.20.00)
powernow-k8: fid 0x2 (1000 MHz), vid 0x12
powernow-k8: fid 0xa (1800 MHz), vid 0xa
powernow-k8: fid 0xc (2000 MHz), vid 0x8
powernow-k8: fid 0xe (2200 MHz), vid 0x8
Marking TSC unstable due to cpufreq changes
powernow-k8: fid trans failed, fid 0x2, curr 0x0
BUG: unable to handle kernel paging request at ffff880807e07b78
IP: [<ffffffff81479163>] cpufreq_stats_update+0x46/0x5b
.. snip..
Pid: 1, comm: swapper Not tainted 3.0.0-rc2 #45 MICRO-STAR INTERNATIONAL CO., LTD MS-7094/MS-7094
..snip..
Call Trace:
[<ffffffff81479248>] cpufreq_stat_notifier_trans+0x48/0x7c
[<ffffffff81095d68>] notifier_call_chain+0x32/0x5e
[<ffffffff81095e6b>] __srcu_notifier_call_chain+0x47/0x63
[<ffffffff81095e96>] srcu_notifier_call_chain+0xf/0x11
[<ffffffff81477e7a>] cpufreq_notify_transition+0x111/0x134
[<ffffffff8147b0d4>] powernowk8_target+0x53b/0x617
[<ffffffff8147723a>] __cpufreq_driver_target+0x2e/0x30
[<ffffffff8147a127>] cpufreq_governor_dbs+0x339/0x356
[<ffffffff81477394>] __cpufreq_governor+0xa8/0xe9
[<ffffffff81477525>] __cpufreq_set_policy+0x132/0x13e
[<ffffffff8147848d>] cpufreq_add_dev_interface+0x272/0x28c
Reported-by: Tobias Diedrich <ranma+xen@tdiedrich.de>
Tested-by: Tobias Diedrich <ranma+xen@tdiedrich.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Dave Jones <davej@redhat.com>
cpufreq_stats leaves behind its sysfs entries, which causes a panic
when something stumbled across them.
(Discovered by unloading cpufreq_stats while powertop was loaded).
Signed-off-by: Dave Jones <davej@redhat.com>
Cc: stable@kernel.org
Concluding interface update and movement of the driver by making
the DB8500 cpufreq driver compile in the cpufreq subsystem.
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
This updates the ux500 cpufreq driver to the new interface from the
updated DB8500 PRCMU
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
As part of the ARM arch subsystem migration, move the DB8500
cpufreq driver to drivers/cpufreq as discussed with Dave Jones. The
Makefile is not updated in order to avoid cross-subsystem conflicts
for this file in merges.
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
* 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, cpu: Fix detection of Celeron Covington stepping A1 and B0
Documentation, ABI: Update L3 cache index disable text
x86, AMD, cacheinfo: Fix L3 cache index disable checks
x86, AMD, cacheinfo: Fix fallout caused by max3 conversion
x86, cpu: Change NOP selection for certain Intel CPUs
x86, cpu: Clean up and unify the NOP selection infrastructure
x86, percpu: Use ASM_NOP4 instead of hardcoding P6_NOP4
x86, cpu: Move AMD Elan Kconfig under "Processor family"
Fix up trivial conflicts in alternative handling (commit dc326fca2b
"x86, cpu: Clean up and unify the NOP selection infrastructure" removed
some hacky 5-byte instruction stuff, while commit d430d3d7e6 "jump
label: Introduce static_branch() interface" renamed HAVE_JUMP_LABEL to
CONFIG_JUMP_LABEL in the code that went away)
Since format string handling is part of request_module, there is no
need to construct the module name. As such, drop the redundant sprintf
and heap usage.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: Dave Jones <davej@redhat.com>
When a CPU is taken offline in an SMP system, cpufreq_remove_dev()
nulls out the per-cpu policy before cpufreq_stats_free_table() can
make use of it. cpufreq_stats_free_table() then skips the
call to sysfs_remove_group(), leaving about 100 bytes of sysfs-related
memory unclaimed each time a CPU-removal occurs. Break up
cpu_stats_free_table into sysfs and table portions, and
call the sysfs portion early.
Signed-off-by: Steven Finney <steven.finney@palm.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Cc: stable@kernel.org
With dynamic debug having gained the capability to report debug messages
also during the boot process, it offers a far superior interface for
debug messages than the custom cpufreq infrastructure. As a first step,
remove the old cpufreq_debug_printk() function and replace it with a call
to the generic pr_debug() function.
How can dynamic debug be used on cpufreq? You need a kernel which has
CONFIG_DYNAMIC_DEBUG enabled.
To enabled debugging during runtime, mount debugfs and
$ echo -n 'module cpufreq +p' > /sys/kernel/debug/dynamic_debug/control
for debugging the complete "cpufreq" module. To achieve the same goal during
boot, append
ddebug_query="module cpufreq +p"
as a boot parameter to the kernel of your choice.
For more detailled instructions, please see
Documentation/dynamic-debug-howto.txt
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Dave Jones <davej@redhat.com>
When we discover CPUs that are affected by each other's
frequency/voltage transitions, the first CPU gets a sysfs directory
created, and rest of the siblings get symlinks. Currently, when we
hotplug off only the first CPU, all of the symlinks and the sysfs
directory gets removed. Even though rest of the siblings are still
online and functional, they are orphaned, and no longer governed by
cpufreq.
This patch, given the above scenario, creates a sysfs directory for
the first sibling and symlinks for the rest of the siblings.
Please note the recursive call, it was rather too ugly to roll it
out. And the removal of redundant NULL setting (it is already taken
care of near the top of the function).
Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Acked-by: Mark Langsdorf <mark.langsdorf@amd.com>
Reviewed-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
Cc: stable@kernel.org
The cpufreq subsystem uses sysdev suspend and resume for
executing cpufreq_suspend() and cpufreq_resume(), respectively,
during system suspend, after interrupts have been switched off on the
boot CPU, and during system resume, while interrupts are still off on
the boot CPU. In both cases the other CPUs are off-line at the
relevant point (either they have been switched off via CPU hotplug
during suspend, or they haven't been switched on yet during resume).
For this reason, although it may seem that cpufreq_suspend() and
cpufreq_resume() are executed for all CPUs in the system, they are
only called for the boot CPU in fact, which is quite confusing.
To remove the confusion and to prepare for elimiating sysdev
suspend and resume operations from the kernel enirely, convernt
cpufreq to using a struct syscore_ops object for the boot CPU
suspend and resume and rename the callbacks so that their names
reflect their purpose. In addition, put some explanatory remarks
into their kerneldoc comments.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
None of the existing cpufreq drivers uses the second argument of
its .suspend() callback (which isn't useful anyway), so remove it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Dave Jones <davej@redhat.com>
There cannot be any concurrent access to these through
different cpu sysfs files anymore, because these tunables
are now all global (not per cpu).
I still have some doubts whether some of these locks
were needed at all. Anyway, let's get rid of them.
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org
Marked deprecated for quite a whilte now...
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org
Marked deprecated for quite a while now...
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
CC: cpufreq@vger.kernel.org
calculate ondemand delay after dbs_check_cpu call because it can
modify rate_mult value
use freq_lo_jiffies value for the sub sample period of powersave_bias mode
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Dave Jones <davej@redhat.com>
* 'for-2.6.39' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: fix build failure introduced by s/freezeable/freezable/
workqueue: add system_freezeable_wq
rds/ib: use system_wq instead of rds_ib_fmr_wq
net/9p: replace p9_poll_task with a work
net/9p: use system_wq instead of p9_mux_wq
xfs: convert to alloc_workqueue()
reiserfs: make commit_wq use the default concurrency level
ocfs2: use system_wq instead of ocfs2_quota_wq
ext4: convert to alloc_workqueue()
scsi/scsi_tgt_lib: scsi_tgtd isn't used in memory reclaim path
scsi/be2iscsi,qla2xxx: convert to alloc_workqueue()
misc/iwmc3200top: use system_wq instead of dedicated workqueues
i2o: use alloc_workqueue() instead of create_workqueue()
acpi: kacpi*_wq don't need WQ_MEM_RECLAIM
fs/aio: aio_wq isn't used in memory reclaim path
input/tps6507x-ts: use system_wq instead of dedicated workqueue
cpufreq: use system_wq instead of dedicated workqueues
wireless/ipw2x00: use system_wq instead of dedicated workqueues
arm/omap: use system_wq in mailbox
workqueue: use WQ_MEM_RECLAIM instead of WQ_RESCUER
cpufreq_register_driver sets cpufreq_driver to a structure owned (and
placed) in the caller's memory. If cpufreq policy fails in its ->init
function, sysdev_driver_register returns nonzero in
cpufreq_register_driver. Now, cpufreq_register_driver returns an error
without setting cpufreq_driver back to NULL.
Usually cpufreq policy modules are unloaded because they propagate the
error to the module init function and return that.
So a later access to any member of cpufreq_driver causes bugs like:
BUG: unable to handle kernel paging request at ffffffffa00270a0
IP: [<ffffffff8145eca3>] cpufreq_cpu_get+0x53/0xe0
PGD 1805067 PUD 1809063 PMD 1c3f90067 PTE 0
Oops: 0000 [#1] SMP
last sysfs file: /sys/devices/virtual/net/tun0/statistics/collisions
CPU 0
Modules linked in: ...
Pid: 5677, comm: thunderbird-bin Tainted: G W 2.6.38-rc4-mm1_64+ #1389 To be filled by O.E.M./To Be Filled By O.E.M.
RIP: 0010:[<ffffffff8145eca3>] [<ffffffff8145eca3>] cpufreq_cpu_get+0x53/0xe0
RSP: 0018:ffff8801aec37d98 EFLAGS: 00010086
RAX: 0000000000000202 RBX: 0000000000000000 RCX: 0000000000000001
RDX: ffffffffa00270a0 RSI: 0000000000001000 RDI: ffffffff8199ece8
...
Call Trace:
[<ffffffff8145f490>] cpufreq_quick_get+0x10/0x30
[<ffffffff8103f12b>] show_cpuinfo+0x2ab/0x300
[<ffffffff81136292>] seq_read+0xf2/0x3f0
[<ffffffff8126c5d3>] ? __strncpy_from_user+0x33/0x60
[<ffffffff8116850d>] proc_reg_read+0x6d/0xa0
[<ffffffff81116e53>] vfs_read+0xc3/0x180
[<ffffffff81116f5c>] sys_read+0x4c/0x90
[<ffffffff81030dbb>] system_call_fastpath+0x16/0x1b
...
It's all cause by weird fail path handling in cpufreq_register_driver.
To fix that, shuffle the code to do proper handling with gotos.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Dave Jones <davej@redhat.com>
With cmwq, there's no reason for cpufreq drivers to use separate
workqueues. Remove the dedicated workqueues from cpufreq_conservative
and cpufreq_ondemand and use system_wq instead. The work items are
already sync canceled on stop, so it's already guaranteed that no work
is running on module exit.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Dave Jones <davej@redhat.com>
Cc: cpufreq@vger.kernel.org
The meaning of CONFIG_EMBEDDED has long since been obsoleted; the option
is used to configure any non-standard kernel with a much larger scope than
only small devices.
This patch renames the option to CONFIG_EXPERT in init/Kconfig and fixes
references to the option throughout the kernel. A new CONFIG_EMBEDDED
option is added that automatically selects CONFIG_EXPERT when enabled and
can be used in the future to isolate options that should only be
considered for embedded systems (RISC architectures, SLOB, etc).
Calling the option "EXPERT" more accurately represents its intention: only
expert users who understand the impact of the configuration changes they
are making should enable it.
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Acked-by: David Woodhouse <david.woodhouse@intel.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Greg KH <gregkh@suse.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Robin Holt <holt@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
