linux-stable.git/drivers/cpufreq, branch linux-3.17.y Linux kernel stable tree cpufreq: Avoid crash in resume on SMP without OPP 2014-11-21T17:23:13+00:00 Geert Uytterhoeven geert+renesas@glider.be 2014-11-04T16:05:25+00:00 df424f3660e1b2aef66fc9263336ee33f46620af commit 09712f557b31838092e1f22a5f2dd131a843a3de upstream. When resuming from s2ram on an SMP system without cpufreq operating points (e.g. there's no "operating-points" property for the CPU node in DT, or the platform doesn't use DT yet), the kernel crashes when bringing CPU 1 online: Enabling non-boot CPUs ... CPU1: Booted secondary processor Unable to handle kernel NULL pointer dereference at virtual address 0000003c pgd = ee5e6b00 [0000003c] *pgd=6e579003, *pmd=6e588003, *pte=00000000 Internal error: Oops: a07 [#1] SMP ARM Modules linked in: CPU: 0 PID: 1246 Comm: s2ram Tainted: G W 3.18.0-rc3-koelsch-01614-g0377af242bb175c8-dirty #589 task: eeec5240 ti: ee704000 task.ti: ee704000 PC is at __cpufreq_add_dev.isra.24+0x24c/0x77c LR is at __cpufreq_add_dev.isra.24+0x244/0x77c pc : [<c0298efc>] lr : [<c0298ef4>] psr: 60000153 sp : ee705d48 ip : ee705d48 fp : ee705d84 r10: c04e0450 r9 : 00000000 r8 : 00000001 r7 : c05426a8 r6 : 00000001 r5 : 00000001 r4 : 00000000 r3 : 00000000 r2 : 00000000 r1 : 20000153 r0 : c0542734 Verify that policy is not NULL before dereferencing it to fix this. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Fixes: 8414809c6a1e (cpufreq: Preserve policy structure across suspend/resume) Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 09712f557b31838092e1f22a5f2dd131a843a3de upstream.

When resuming from s2ram on an SMP system without cpufreq operating
points (e.g. there's no "operating-points" property for the CPU node in
DT, or the platform doesn't use DT yet), the kernel crashes when
bringing CPU 1 online:

    Enabling non-boot CPUs ...
    CPU1: Booted secondary processor
    Unable to handle kernel NULL pointer dereference at virtual address 0000003c
    pgd = ee5e6b00
    [0000003c] *pgd=6e579003, *pmd=6e588003, *pte=00000000
    Internal error: Oops: a07 [#1] SMP ARM
    Modules linked in:
    CPU: 0 PID: 1246 Comm: s2ram Tainted: G        W      3.18.0-rc3-koelsch-01614-g0377af242bb175c8-dirty #589
    task: eeec5240 ti: ee704000 task.ti: ee704000
    PC is at __cpufreq_add_dev.isra.24+0x24c/0x77c
    LR is at __cpufreq_add_dev.isra.24+0x244/0x77c
    pc : [<c0298efc>]    lr : [<c0298ef4>]    psr: 60000153
    sp : ee705d48  ip : ee705d48  fp : ee705d84
    r10: c04e0450  r9 : 00000000  r8 : 00000001
    r7 : c05426a8  r6 : 00000001  r5 : 00000001  r4 : 00000000
    r3 : 00000000  r2 : 00000000  r1 : 20000153  r0 : c0542734

Verify that policy is not NULL before dereferencing it to fix this.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Fixes: 8414809c6a1e (cpufreq: Preserve policy structure across suspend/resume)
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
intel_pstate: Correct BYT VID values. 2014-11-14T18:10:31+00:00 Dirk Brandewie dirk.j.brandewie@intel.com 2014-10-13T15:37:44+00:00 18377d39177e358c4bb599f5de415cbd9ee0d882 commit d022a65ed2473fac4a600e3424503dc571160a3e upstream. Using a VID value that is not high enough for the requested P state can cause machine checks. Add a ceiling function to ensure calulated VIDs with fractional values are set to the next highest integer VID value. The algorythm for calculating the non-trubo VID from the BIOS writers guide is: vid_ratio = (vid_max - vid_min) / (max_pstate - min_pstate) vid = ceiling(vid_min + (req_pstate - min_pstate) * vid_ratio) Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d022a65ed2473fac4a600e3424503dc571160a3e upstream.

Using a VID value that is not high enough for the requested P state can
cause machine checks. Add a ceiling function to ensure calulated VIDs
with fractional values are set to the next highest integer VID value.

The algorythm for calculating the non-trubo VID from the BIOS writers
guide is:
 vid_ratio = (vid_max - vid_min) / (max_pstate - min_pstate)
 vid = ceiling(vid_min + (req_pstate - min_pstate) * vid_ratio)

Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
intel_pstate: Fix BYT frequency reporting 2014-11-14T18:10:31+00:00 Dirk Brandewie dirk.j.brandewie@intel.com 2014-10-13T15:37:43+00:00 57a14053d1b90d14f04fca3c21c315bad01c5329 commit b27580b05e6f5253228debc60b8ff4a786ff573a upstream. BYT has a different conversion from P state to frequency than the core processors. This causes the min/max and current frequency to be misreported on some BYT SKUs. Tested on BYT N2820, Ivybridge and Haswell processors. Link: https://bugzilla.yoctoproject.org/show_bug.cgi?id=6663 Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b27580b05e6f5253228debc60b8ff4a786ff573a upstream.

BYT has a different conversion from P state to frequency than the core
processors.  This causes the min/max and current frequency to be
misreported on some BYT SKUs. Tested on BYT N2820, Ivybridge and
Haswell processors.

Link: https://bugzilla.yoctoproject.org/show_bug.cgi?id=6663
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
intel_pstate: Don't lose sysfs settings during cpu offline 2014-11-14T18:10:31+00:00 Dirk Brandewie dirk.j.brandewie@intel.com 2014-10-13T15:37:42+00:00 29cf079c2406a4e1fc443da2ecd6faa30754ebac commit c034871712730a33e0267095f48b62eae958499c upstream. The user may have custom settings don't destroy them during suspend. Link: https://bugzilla.kernel.org/show_bug.cgi?id=80651 Reported-by: Tobias Jakobi <liquid.acid@gmx.net> Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c034871712730a33e0267095f48b62eae958499c upstream.

The user may have custom settings don't destroy them during suspend.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=80651
Reported-by: Tobias Jakobi <liquid.acid@gmx.net>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: intel_pstate: Fix setting max_perf_pct in performance policy 2014-11-14T18:10:31+00:00 Pali Rohár pali.rohar@gmail.com 2014-10-15T23:16:51+00:00 372089844abaa2e8b633bfd432a3ff04ab9a222e commit 36b4bed5cd8f6e17019fa7d380e0836872c7b367 upstream. Code which changes policy to powersave changes also max_policy_pct based on max_freq. Code which change max_perf_pct has upper limit base on value max_policy_pct. When policy is changing from powersave back to performance then max_policy_pct is not changed. Which means that changing max_perf_pct is not possible to high values if max_freq was too low in powersave policy. Test case: $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq 800000 $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq 3300000 $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor performance $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct 100 $ echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor $ echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq $ echo 20 > /sys/devices/system/cpu/intel_pstate/max_perf_pct $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor powersave $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq 800000 $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct 20 $ echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor $ echo 3300000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq $ echo 100 > /sys/devices/system/cpu/intel_pstate/max_perf_pct $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor performance $ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq 3300000 $ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct 24 And now intel_pstate driver allows to set maximal value for max_perf_pct based on max_policy_pct which is 24 for previous powersave max_freq 800000. This patch will set default value for max_policy_pct when setting policy to performance so it will allow to set also max value for max_perf_pct. Signed-off-by: Pali Rohár <pali.rohar@gmail.com> Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 36b4bed5cd8f6e17019fa7d380e0836872c7b367 upstream.

Code which changes policy to powersave changes also max_policy_pct based on
max_freq. Code which change max_perf_pct has upper limit base on value
max_policy_pct. When policy is changing from powersave back to performance
then max_policy_pct is not changed. Which means that changing max_perf_pct is
not possible to high values if max_freq was too low in powersave policy.

Test case:

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
800000
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
3300000
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
100

$ echo powersave > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
$ echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
$ echo 20 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
powersave
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
800000
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
20

$ echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
$ echo 3300000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
$ echo 100 > /sys/devices/system/cpu/intel_pstate/max_perf_pct

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
performance
$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
3300000
$ cat /sys/devices/system/cpu/intel_pstate/max_perf_pct
24

And now intel_pstate driver allows to set maximal value for max_perf_pct based
on max_policy_pct which is 24 for previous powersave max_freq 800000.

This patch will set default value for max_policy_pct when setting policy to
performance so it will allow to set also max value for max_perf_pct.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: intel_pstate: Reflect current no_turbo state correctly 2014-11-14T18:10:31+00:00 Gabriele Mazzotta gabriele.mzt@gmail.com 2014-10-13T15:37:41+00:00 32c54bdcfa8fc6c77431a185e7907339021aa747 commit 4521e1a0ce173daa23dfef8312d09051e057ff8e upstream. Some BIOSes modify the state of MSR_IA32_MISC_ENABLE_TURBO_DISABLE based on the current power source for the system battery AC vs battery. Reflect the correct current state and ability to modify the no_turbo sysfs file based on current state of MSR_IA32_MISC_ENABLE_TURBO_DISABLE. Link: https://bugzilla.kernel.org/show_bug.cgi?id=83151 Signed-off-by: Gabriele Mazzotta <gabriele.mzt@gmail.com> Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4521e1a0ce173daa23dfef8312d09051e057ff8e upstream.

Some BIOSes modify the state of MSR_IA32_MISC_ENABLE_TURBO_DISABLE
based on the current power source for the system battery AC vs
battery. Reflect the correct current state and ability to modify the
no_turbo sysfs file based on current state of
MSR_IA32_MISC_ENABLE_TURBO_DISABLE.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=83151
Signed-off-by: Gabriele Mazzotta <gabriele.mzt@gmail.com>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: expose scaling_cur_freq sysfs file for set_policy() drivers 2014-11-14T18:10:31+00:00 Dirk Brandewie dirk.j.brandewie@intel.com 2014-10-13T15:37:40+00:00 b79ac56d6276d7ca7a5dc9da194138e4c3e18bd6 commit c034b02e213d271b98c45c4a7b54af8f69aaac1e upstream. Currently the core does not expose scaling_cur_freq for set_policy() drivers this breaks some userspace monitoring tools. Change the core to expose this file for all drivers and if the set_policy() driver supports the get() callback use it to retrieve the current frequency. Link: https://bugzilla.kernel.org/show_bug.cgi?id=73741 Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c034b02e213d271b98c45c4a7b54af8f69aaac1e upstream.

Currently the core does not expose scaling_cur_freq for set_policy()
drivers this breaks some userspace monitoring tools.
Change the core to expose this file for all drivers and if the
set_policy() driver supports the get() callback use it to retrieve the
current frequency.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=73741
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cpufreq: update 'cpufreq_suspended' after stopping governors 2014-09-30T19:02:34+00:00 Viresh Kumar viresh.kumar@linaro.org 2014-09-30T04:03:17+00:00 b1b12babe3b72cfb08b875245e5a5d7c2747c772 Commit 8e30444e1530 ("cpufreq: fix cpufreq suspend/resume for intel_pstate") introduced a bug where the governors wouldn't be stopped anymore for ->target{_index}() drivers during suspend. This happens because 'cpufreq_suspended' is updated before stopping the governors during suspend and due to this __cpufreq_governor() would return early due to this check: /* Don't start any governor operations if we are entering suspend */ if (cpufreq_suspended) return 0; Fixes: 8e30444e1530 ("cpufreq: fix cpufreq suspend/resume for intel_pstate") Cc: 3.15+ <stable@vger.kernel.org> # 3.15+: 8e30444e1530 "cpufreq: fix cpufreq suspend/resume for intel_pstate" Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Commit 8e30444e1530 ("cpufreq: fix cpufreq suspend/resume for intel_pstate")
introduced a bug where the governors wouldn't be stopped anymore for
->target{_index}() drivers during suspend. This happens because
'cpufreq_suspended' is updated before stopping the governors during suspend
and due to this __cpufreq_governor() would return early due to this check:

	/* Don't start any governor operations if we are entering suspend */
	if (cpufreq_suspended)
		return 0;

Fixes: 8e30444e1530 ("cpufreq: fix cpufreq suspend/resume for intel_pstate")
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+: 8e30444e1530 "cpufreq: fix cpufreq suspend/resume for intel_pstate"
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: integrator: fix integrator_cpufreq_remove return type 2014-09-29T13:36:03+00:00 Arnd Bergmann arnd@arndb.de 2014-09-26T20:19:12+00:00 d62dbf77f7dfaa6fb455b4b9828069a11965929c When building this driver as a module, we get a helpful warning about the return type: drivers/cpufreq/integrator-cpufreq.c:232:2: warning: initialization from incompatible pointer type .remove = __exit_p(integrator_cpufreq_remove), If the remove callback returns void, the caller gets an undefined value as it expects an integer to be returned. This fixes the problem by passing down the value from cpufreq_unregister_driver. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: All applicable <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
When building this driver as a module, we get a helpful warning
about the return type:

drivers/cpufreq/integrator-cpufreq.c:232:2: warning: initialization from incompatible pointer type
  .remove = __exit_p(integrator_cpufreq_remove),

If the remove callback returns void, the caller gets an undefined
value as it expects an integer to be returned. This fixes the
problem by passing down the value from cpufreq_unregister_driver.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpufreq: pcc-cpufreq: Fix wait_event() under spinlock 2014-09-29T13:35:50+00:00 Rafael J. Wysocki rafael.j.wysocki@intel.com 2014-09-27T19:56:08+00:00 e65b5ddba84634f31d42dfd86013f4c6be5e9e32 Fix the following bug introduced by commit 8fec051eea73 (cpufreq: Convert existing drivers to use cpufreq_freq_transition_{begin|end}) that forgot to move the spin_lock() in pcc_cpufreq_target() past cpufreq_freq_transition_begin() which calls wait_event(): BUG: sleeping function called from invalid context at drivers/cpufreq/cpufreq.c:370 in_atomic(): 1, irqs_disabled(): 0, pid: 2636, name: modprobe Preemption disabled at:[<ffffffffa04d74d7>] pcc_cpufreq_target+0x27/0x200 [pcc_cpufreq] [ 51.025044] CPU: 57 PID: 2636 Comm: modprobe Tainted: G E 3.17.0-default #7 Hardware name: Hewlett-Packard ProLiant DL980 G7, BIOS P66 07/07/2010 00000000ffffffff ffff88026c46b828 ffffffff81589dbd 0000000000000000 ffff880037978090 ffff88026c46b848 ffffffff8108e1df ffff880037978090 0000000000000000 ffff88026c46b878 ffffffff8108e298 ffff88026d73ec00 Call Trace: [<ffffffff81589dbd>] dump_stack+0x4d/0x90 [<ffffffff8108e1df>] ___might_sleep+0x10f/0x180 [<ffffffff8108e298>] __might_sleep+0x48/0xd0 [<ffffffff8145b905>] cpufreq_freq_transition_begin+0x75/0x140 drivers/cpufreq/cpufreq.c:370 wait_event(policy->transition_wait, !policy->transition_ongoing); [<ffffffff8108fc99>] ? preempt_count_add+0xb9/0xc0 [<ffffffffa04d7513>] pcc_cpufreq_target+0x63/0x200 [pcc_cpufreq] drivers/cpufreq/pcc-cpufreq.c:207 spin_lock(&pcc_lock); [<ffffffff810e0d0f>] ? update_ts_time_stats+0x7f/0xb0 [<ffffffff8145be55>] __cpufreq_driver_target+0x85/0x170 [<ffffffff8145e4c8>] od_check_cpu+0xa8/0xb0 [<ffffffff8145ef10>] dbs_check_cpu+0x180/0x1d0 [<ffffffff8145f310>] cpufreq_governor_dbs+0x3b0/0x720 [<ffffffff8145ebe3>] od_cpufreq_governor_dbs+0x33/0xe0 [<ffffffff814593d9>] __cpufreq_governor+0xa9/0x210 [<ffffffff81459fb2>] cpufreq_set_policy+0x1e2/0x2e0 [<ffffffff8145a6cc>] cpufreq_init_policy+0x8c/0x110 [<ffffffff8145c9a0>] ? cpufreq_update_policy+0x1b0/0x1b0 [<ffffffff8108fb99>] ? preempt_count_sub+0xb9/0x100 [<ffffffff8145c6c6>] __cpufreq_add_dev+0x596/0x6b0 [<ffffffffa016c608>] ? pcc_cpufreq_probe+0x4b4/0x4b4 [pcc_cpufreq] [<ffffffff8145c7ee>] cpufreq_add_dev+0xe/0x10 [<ffffffff81408e81>] subsys_interface_register+0xc1/0xf0 [<ffffffff8108fb99>] ? preempt_count_sub+0xb9/0x100 [<ffffffff8145b3d7>] cpufreq_register_driver+0x117/0x2a0 [<ffffffffa016c65d>] pcc_cpufreq_init+0x55/0x9f8 [pcc_cpufreq] [<ffffffffa016c608>] ? pcc_cpufreq_probe+0x4b4/0x4b4 [pcc_cpufreq] [<ffffffff81000298>] do_one_initcall+0xc8/0x1f0 [<ffffffff811a731d>] ? __vunmap+0x9d/0x100 [<ffffffff810eb9a0>] do_init_module+0x30/0x1b0 [<ffffffff810edfa6>] load_module+0x686/0x710 [<ffffffff810ebb20>] ? do_init_module+0x1b0/0x1b0 [<ffffffff810ee1db>] SyS_init_module+0x9b/0xc0 [<ffffffff8158f7a9>] system_call_fastpath+0x16/0x1b Fixes: 8fec051eea73 (cpufreq: Convert existing drivers to use cpufreq_freq_transition_{begin|end}) Reported-and-tested-by: Mike Galbraith <umgwanakikbuti@gmail.com> Cc: 3.15+ <stable@vger.kernel.org> # 3.15+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> 
Fix the following bug introduced by commit 8fec051eea73 (cpufreq:
Convert existing drivers to use cpufreq_freq_transition_{begin|end})
that forgot to move the spin_lock() in pcc_cpufreq_target() past
cpufreq_freq_transition_begin() which calls wait_event():

BUG: sleeping function called from invalid context at drivers/cpufreq/cpufreq.c:370
in_atomic(): 1, irqs_disabled(): 0, pid: 2636, name: modprobe
Preemption disabled at:[<ffffffffa04d74d7>] pcc_cpufreq_target+0x27/0x200 [pcc_cpufreq]
[   51.025044]
CPU: 57 PID: 2636 Comm: modprobe Tainted: G            E  3.17.0-default #7
Hardware name: Hewlett-Packard ProLiant DL980 G7, BIOS P66 07/07/2010
 00000000ffffffff ffff88026c46b828 ffffffff81589dbd 0000000000000000
 ffff880037978090 ffff88026c46b848 ffffffff8108e1df ffff880037978090
 0000000000000000 ffff88026c46b878 ffffffff8108e298 ffff88026d73ec00
Call Trace:
 [<ffffffff81589dbd>] dump_stack+0x4d/0x90
 [<ffffffff8108e1df>] ___might_sleep+0x10f/0x180
 [<ffffffff8108e298>] __might_sleep+0x48/0xd0
 [<ffffffff8145b905>] cpufreq_freq_transition_begin+0x75/0x140 drivers/cpufreq/cpufreq.c:370 wait_event(policy->transition_wait, !policy->transition_ongoing);
 [<ffffffff8108fc99>] ? preempt_count_add+0xb9/0xc0
 [<ffffffffa04d7513>] pcc_cpufreq_target+0x63/0x200 [pcc_cpufreq] drivers/cpufreq/pcc-cpufreq.c:207 spin_lock(&pcc_lock);
 [<ffffffff810e0d0f>] ? update_ts_time_stats+0x7f/0xb0
 [<ffffffff8145be55>] __cpufreq_driver_target+0x85/0x170
 [<ffffffff8145e4c8>] od_check_cpu+0xa8/0xb0
 [<ffffffff8145ef10>] dbs_check_cpu+0x180/0x1d0
 [<ffffffff8145f310>] cpufreq_governor_dbs+0x3b0/0x720
 [<ffffffff8145ebe3>] od_cpufreq_governor_dbs+0x33/0xe0
 [<ffffffff814593d9>] __cpufreq_governor+0xa9/0x210
 [<ffffffff81459fb2>] cpufreq_set_policy+0x1e2/0x2e0
 [<ffffffff8145a6cc>] cpufreq_init_policy+0x8c/0x110
 [<ffffffff8145c9a0>] ? cpufreq_update_policy+0x1b0/0x1b0
 [<ffffffff8108fb99>] ? preempt_count_sub+0xb9/0x100
 [<ffffffff8145c6c6>] __cpufreq_add_dev+0x596/0x6b0
 [<ffffffffa016c608>] ? pcc_cpufreq_probe+0x4b4/0x4b4 [pcc_cpufreq]
 [<ffffffff8145c7ee>] cpufreq_add_dev+0xe/0x10
 [<ffffffff81408e81>] subsys_interface_register+0xc1/0xf0
 [<ffffffff8108fb99>] ? preempt_count_sub+0xb9/0x100
 [<ffffffff8145b3d7>] cpufreq_register_driver+0x117/0x2a0
 [<ffffffffa016c65d>] pcc_cpufreq_init+0x55/0x9f8 [pcc_cpufreq]
 [<ffffffffa016c608>] ? pcc_cpufreq_probe+0x4b4/0x4b4 [pcc_cpufreq]
 [<ffffffff81000298>] do_one_initcall+0xc8/0x1f0
 [<ffffffff811a731d>] ? __vunmap+0x9d/0x100
 [<ffffffff810eb9a0>] do_init_module+0x30/0x1b0
 [<ffffffff810edfa6>] load_module+0x686/0x710
 [<ffffffff810ebb20>] ? do_init_module+0x1b0/0x1b0
 [<ffffffff810ee1db>] SyS_init_module+0x9b/0xc0
 [<ffffffff8158f7a9>] system_call_fastpath+0x16/0x1b

Fixes: 8fec051eea73 (cpufreq: Convert existing drivers to use cpufreq_freq_transition_{begin|end})
Reported-and-tested-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>