path: root/drivers/cpufreq
AgeCommit message (Collapse)Author
2014-02-14Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidlinux-linaro-lsk-v3.10-androidlinux-linaro-lsk-androidMark Brown
2014-02-14Merge tag 'v3.10.30' into linux-linaro-lskHEADlinux-linaro-lsk-v3.10linux-linaro-lskMark Brown
This is the 3.10.30 stable release
2014-02-13intel_pstate: Correct calculation of min pstate valueDirk Brandewie
commit 7244cb62d96e735847dc9d08f870550df896898c upstream. The minimum pstate is supposed to be a percentage of the maximum P state available. Calculate min using max pstate and not the current max which may have been limited by the user 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>
2014-02-13intel_pstate: Improve accuracy by not truncating until final resultBrennan Shacklett
commit d253d2a52676cfa3d89b8f0737a08ce7db665207 upstream. This patch addresses Bug 60727 (https://bugzilla.kernel.org/show_bug.cgi?id=60727) which was due to the truncation of intermediate values in the calculations, which causes the code to consistently underestimate the current cpu frequency, specifically 100% cpu utilization was truncated down to the setpoint of 97%. This patch fixes the problem by keeping the results of all intermediate calculations as fixed point numbers rather scaling them back and forth between integers and fixed point. References: https://bugzilla.kernel.org/show_bug.cgi?id=60727 Signed-off-by: Brennan Shacklett <bpshacklett@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>
2014-02-13intel_pstate: fix no_turboSrinivas Pandruvada
commit 1ccf7a1cdafadd02e33e8f3d74370685a0600ec6 upstream. When sysfs for no_turbo is set, then also some p states in turbo regions are observed. This patch will set IDA Engage bit when no_turbo is set to explicitly disengage turbo. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.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>
2014-02-13intel_pstate: Add Haswell CPU modelsNell Hardcastle
commit 6cdcdb793791f776ea9408581b1242b636d43b37 upstream. Enable the intel_pstate driver for Haswell CPUs. One missing Ivy Bridge model (0x3E) is also included. Models referenced from tools/power/x86/turbostat/turbostat.c:has_nehalem_turbo_ratio_limit Signed-off-by: Nell Hardcastle <nell@spicious.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> 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>
2014-01-22Merge branch 'linaro-android-3.10-lsk' of ↵Mark Brown
git://git.linaro.org/people/jstultz/android into linux-linaro-lsk-android
2014-01-16Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidAlex Shi
2014-01-16Merge remote-tracking branch 'stable/linux-3.10.y' 3.10.27 into linux-linaro-lskAlex Shi
2014-01-15intel_pstate: Add X86_FEATURE_APERFMPERF to cpu match parameters.Dirk Brandewie
commit 6cbd7ee10e2842a3d1f9b60abede1c8f3d1f1130 upstream. KVM environments do not support APERF/MPERF MSRs. intel_pstate cannot operate without these registers. The previous validity checks in intel_pstate_msrs_not_valid() are insufficent in nested KVMs. References: https://bugzilla.redhat.com/show_bug.cgi?id=1046317 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>
2014-01-10Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidAlex Shi
Conflicts: include/linux/mm_types.h
2014-01-10Merge remote-tracking branch 'stable/linux-3.10.y' into linux-linaro-lskAlex Shi
Conflicts: arch/arm64/kernel/smp.c Signed-off-by: Alex Shi <alex.shi@linaro.org>
2014-01-09intel_pstate: Fail initialization if P-state information is missingRafael J. Wysocki
commit 98a947abdd54e5de909bebadfced1696ccad30cf upstream. If pstate.current_pstate is 0 after the initial intel_pstate_get_cpu_pstates(), this means that we were unable to obtain any useful P-state information and there is no reason to continue, so free memory and return an error in that case. This fixes the following divide error occuring in a nested KVM guest: Intel P-state driver initializing. Intel pstate controlling: cpu 0 cpufreq: __cpufreq_add_dev: ->get() failed divide error: 0000 [#1] SMP Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.13.0-0.rc4.git5.1.fc21.x86_64 #1 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 task: ffff88001ea20000 ti: ffff88001e9bc000 task.ti: ffff88001e9bc000 RIP: 0010:[<ffffffff815c551d>] [<ffffffff815c551d>] intel_pstate_timer_func+0x11d/0x2b0 RSP: 0000:ffff88001ee03e18 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88001a454348 RCX: 0000000000006100 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88001ee03e38 R08: 0000000000000000 R09: 0000000000000000 R10: ffff88001ea20000 R11: 0000000000000000 R12: 00000c0a1ea20000 R13: 1ea200001ea20000 R14: ffffffff815c5400 R15: ffff88001a454348 FS: 0000000000000000(0000) GS:ffff88001ee00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 0000000001c0c000 CR4: 00000000000006f0 Stack: fffffffb1a454390 ffffffff821a4500 ffff88001a454390 0000000000000100 ffff88001ee03ea8 ffffffff81083e9a ffffffff81083e15 ffffffff82d5ed40 ffffffff8258cc60 0000000000000000 ffffffff81ac39de 0000000000000000 Call Trace: <IRQ> [<ffffffff81083e9a>] call_timer_fn+0x8a/0x310 [<ffffffff81083e15>] ? call_timer_fn+0x5/0x310 [<ffffffff815c5400>] ? pid_param_set+0x130/0x130 [<ffffffff81084354>] run_timer_softirq+0x234/0x380 [<ffffffff8107aee4>] __do_softirq+0x104/0x430 [<ffffffff8107b5fd>] irq_exit+0xcd/0xe0 [<ffffffff81770645>] smp_apic_timer_interrupt+0x45/0x60 [<ffffffff8176efb2>] apic_timer_interrupt+0x72/0x80 <EOI> [<ffffffff810e15cd>] ? vprintk_emit+0x1dd/0x5e0 [<ffffffff81757719>] printk+0x67/0x69 [<ffffffff815c1493>] __cpufreq_add_dev.isra.13+0x883/0x8d0 [<ffffffff815c14f0>] cpufreq_add_dev+0x10/0x20 [<ffffffff814a14d1>] subsys_interface_register+0xb1/0xf0 [<ffffffff815bf5cf>] cpufreq_register_driver+0x9f/0x210 [<ffffffff81fb19af>] intel_pstate_init+0x27d/0x3be [<ffffffff81761e3e>] ? mutex_unlock+0xe/0x10 [<ffffffff81fb1732>] ? cpufreq_gov_dbs_init+0x12/0x12 [<ffffffff8100214a>] do_one_initcall+0xfa/0x1b0 [<ffffffff8109dbf5>] ? parse_args+0x225/0x3f0 [<ffffffff81f64193>] kernel_init_freeable+0x1fc/0x287 [<ffffffff81f638d0>] ? do_early_param+0x88/0x88 [<ffffffff8174b530>] ? rest_init+0x150/0x150 [<ffffffff8174b53e>] kernel_init+0xe/0x130 [<ffffffff8176e27c>] ret_from_fork+0x7c/0xb0 [<ffffffff8174b530>] ? rest_init+0x150/0x150 Code: c1 e0 05 48 63 bc 03 10 01 00 00 48 63 83 d0 00 00 00 48 63 d6 48 c1 e2 08 c1 e1 08 4c 63 c2 48 c1 e0 08 48 98 48 c1 e0 08 48 99 <49> f7 f8 48 98 48 0f af f8 48 c1 ff 08 29 f9 89 ca c1 fa 1f 89 RIP [<ffffffff815c551d>] intel_pstate_timer_func+0x11d/0x2b0 RSP <ffff88001ee03e18> ---[ end trace f166110ed22cc37a ]--- Kernel panic - not syncing: Fatal exception in interrupt Reported-and-tested-by: Kashyap Chamarthy <kchamart@redhat.com> Cc: Josh Boyer <jwboyer@fedoraproject.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-02Merge branch 'upstream/android-3.10' into linaro-fixes/android-3.10John Stultz
2014-01-02cpufreq: interactive: fix compiling warningsChih-Wei Huang
The gcc warns like: cpufreq_interactive.c:745:6: warning: operation on 'ret' may be undefined [-Wsequence-point] It was introduced by commit cf0fad49d17cb8273ce555dd5b7afab67d7923bf. Since sprintf(...) just return 1 (one character) in this case, ret should not changed. Just discarding the result of sprintf(...) leads to the result that the committer of cf0fad49d17cb8273ce555dd5b7afab67d7923bf wants. Change-Id: Ifed1cef6d6a31c3ed23dad03a567b3b9eddf3a57 Signed-off-by: Chih-Wei Huang <cwhuang@android-x86.org>
2013-12-12Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidMark Brown
2013-12-09Merge remote-tracking branch 'lsk/v3.10/topic/cpufreq' into linux-linaro-lskMark Brown
2013-12-05cpufreq: enable ARM drivers on arm64v3.10/topic/cpufreqRob Herring
Enable cpufreq and power kconfig menus on arm64 along with arm cpufreq drivers. The power menu is needed for OPP support. At least on Calxeda systems, the same cpufreq driver is used for arm and arm64 based systems. [Submitted upstream by Rob, still in review at the current time] Signed-off-by: Rob Herring <rob.herring@calxeda.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-12-05Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidMark Brown
Conflicts (add/add): drivers/input/evdev.c
2013-12-05Merge tag 'v3.10.22' into linux-linaro-lskMark Brown
This is the 3.10.22 stable release
2013-12-04cpufreq: highbank-cpufreq: Enable Midway/ECX-2000Mark Langsdorf
commit fbbc5bfb44a22e7a8ef753a1c8dfb448d7ac8b85 upstream. Calxeda's new ECX-2000 part uses the same cpufreq interface as highbank, so add it to the driver's compatibility list. This is a minor change that can safely be applied to the 3.10 and 3.11 stable trees. Signed-off-by: Mark Langsdorf <mark.langsdorf@calxeda.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-27Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidMark Brown
2013-11-27Merge remote-tracking branch 'lsk/v3.10/topic/tc2' into linux-linaro-lskMark Brown
2013-11-26cpufreq_stats: improve config option isolationMark Hambleton
Add missing pre-processor protection around calls to IKS APIs Signed-off-by: Mark Hambleton <mahamble@broadcom.com> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-11-14Merge remote-tracking branch 'lsk/v3.10/topic/android-fixes' into ↵Mark Brown
linux-linaro-lsk-android The cpufreq_interactive changes have been merged upstream and the local version dropped. Conflicts: drivers/cpufreq/cpufreq_interactive.c
2013-11-13Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidMark Brown
2013-11-13Merge tag 'v3.10.19' into linux-linaro-lskMark Brown
This is the 3.10.19 stable release
2013-11-13cpufreq / intel_pstate: Fix max_perf_pct on resumeDirk Brandewie
commit 52e0a509e5d6f902ec26bc2a8bb02b137dc453be upstream. If the system is suspended while max_perf_pct is less than 100 percent or no_turbo set policy->{min,max} will be set incorrectly with scaled values which turn the scaled values into hard limits. References: https://bugzilla.kernel.org/show_bug.cgi?id=61241 Reported-by: Patrick Bartels <petzicus@googlemail.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>
2013-11-04Merge branch 'upstream/android-3.10' into linaro-fixes/android-3.10John Stultz
2013-10-17config: Set CPU_FREQ_GOV_INTERACTIVE default nJohn Stultz
The CPU_FREQ_GOV_INTERACTIVE text states: "If in doubt, say N." however the option defaults to Y. Make this consistent by defaulting to n. Change-Id: I9625aa6b083c8ca0a99deb81c1e91b720fc76943 Reported-by: Jon Medhurst (Tixy) <tixy@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
2013-10-16cpufreq: interactive: delete timers for GOV_STARTShridhar Rasal
Make sure that timers cpu_timer and cpu_slack_timer deactivated before addition of new. Change-Id: If31c4049606871df6f00efdc24b1d713c86a6f69 Signed-off-by: Shridhar Rasal <srasal@nvidia.com> Signed-off-by: Bharat Nihalani <bnihalani@nvidia.com>
2013-10-15cpufreq: Interactive: Implement per policy instances of governorViresh Kumar
If we have a multi-package system, where we have multiple instances of struct policy (per package), currently we can't have multiple instances of same governor. i.e. We can't have multiple instances of Interactive governor for multiple packages. This is a bottleneck for multicluster system, where we want different packages to use Interactive governor, but with different tunables. This patch uses the infrastructure provided by earlier patches pushed in Mainline in v3.10-rc1/rc2 and implements per policy instances of Interactive governor. Change-Id: I70436d4a5a45c6cb6edf37f3e46d0b9fbc930982 [toddpoynor@google.com: merge with later code, minor changes] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-10-15cpufreq: interactive: Move definition of cpufreq_gov_interactive downwardsViresh Kumar
This moves definition of cpufreq_gov_interactive towards the bottom of file, so that we don't have to add prototype of cpufreq_governor_interactive() in the beginning of file. Change-Id: I04bd1004954eb36502c5cd7e35d3d7274cddaf95 Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-10-15cpufreq: interactive: Remove unnecessary cpu_online() checkViresh Kumar
Cpufreq no longer calls governor callback for offlined cpus. i.e. All policy->cpus are guaranteed to be online. Hence we don't need explicit check to see if cpu is online or not. Change-Id: I9ad85ea4addd5b4a40952e59ed730dd15e328690 Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-09-19cpufreq: interactive: fix show_target_loads and show_above_hispeed_delayMinsung Kim
Remove a trailing whitespace from target_loads and above_hispeed_delay. Problem happens when user-space program tried to restore parameters that saved before changing parameters. In this case was returned error(EINVAL). Change-Id: I5a74e3824602cd6f2b74651adda5ec1b627e61e9 Signed-off-by: Minsung Kim <ms925.kim@samsung.com>
2013-08-15Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidMark Brown
Conflicts (the ARM security fixes vs the read only kernel changes from Google): arch/arm/mm/mmu.c
2013-08-15Merge tag 'v3.10.7' into linux-linaro-lskMark Brown
This is the 3.10.7 stable release
2013-08-14cpufreq: rename ignore_nice as ignore_nice_loadViresh Kumar
commit 6c4640c3adfd97ce10efed7c07405f52d002b9a8 upstream. This sysfs file was called ignore_nice_load earlier and commit 4d5dcc4 (cpufreq: governor: Implement per policy instances of governors) changed its name to ignore_nice by mistake. Lets get it renamed back to its original name. Reported-by: Martin von Gagern <Martin.vGagern@gmx.net> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-14cpufreq: loongson2: fix regression related to clock managementAaro Koskinen
commit f54fe64d14dff3df6d45a48115d248a82557811f upstream. Commit 42913c799 (MIPS: Loongson2: Use clk API instead of direct dereferences) broke the cpufreq functionality on Loongson2 boards: clk_set_rate() is called before the CPU frequency table is initialized, and therefore will always fail. Fix by moving the clk_set_rate() after the table initialization. Tested on Lemote FuLoong mini-PC. Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-11cpufreq: Fix cpufreq driver module refcount balance after suspend/resumeRafael J. Wysocki
commit 2a99859932281ed6c2ecdd988855f8f6838f6743 upstream. Since cpufreq_cpu_put() called by __cpufreq_remove_dev() drops the driver module refcount, __cpufreq_remove_dev() causes that refcount to become negative for the cpufreq driver after a suspend/resume cycle. This is not the only bad thing that happens there, however, because kobject_put() should only be called for the policy kobject at this point if the CPU is not the last one for that policy. Namely, if the given CPU is the last one for that policy, the policy kobject's refcount should be 1 at this point, as set by cpufreq_add_dev_interface(), and only needs to be dropped once for the kobject to go away. This actually happens under the cpu == 1 check, so it need not be done before by cpufreq_cpu_put(). On the other hand, if the given CPU is not the last one for that policy, this means that cpufreq_add_policy_cpu() has been called at least once for that policy and cpufreq_cpu_get() has been called for it too. To balance that cpufreq_cpu_get(), we need to call cpufreq_cpu_put() in that case. Thus, to fix the described problem and keep the reference counters balanced in both cases, move the cpufreq_cpu_get() call in __cpufreq_remove_dev() to the code path executed only for CPUs that share the policy with other CPUs. Reported-and-tested-by: Toralf Förster <toralf.foerster@gmx.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-11Merge remote-tracking branch 'lsk/v3.10/topic/android-fixes' into ↵Mark Brown
2013-08-11Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidMark Brown
2013-08-08Merge remote-tracking branch 'lsk/v3.10/topic/tc2' into linux-linaro-lskMark Brown
2013-08-08cpufreq: arm-big-little: don't use cpu_last_req_freq for MPViresh Kumar
While getting support for In-Kernel-Switcher in big LITTLE cpufreq driver we introduced cpu_last_req_freq per-cpu variable that stores the last frequency requested for a cpu. It was important for IKS as CPUs in the same cluster can have separate struct cpufreq_policy associated with them and so cpufreq core may try to set different frequencies on both CPUs of same cluster. But for non-IKS solution or MP we don't need to cache last requested frequency. Currently there is a bug in code where if cpufreq_driver->get() is called for any cpu other than policy->cpu, we are returning 0, because we set cpu_last_req_freq only for policy->cpu and not for others. This problem could have been fixed by setting cpu_last_req_freq for all CPUs in policy->cpus, but that wouldn't be the best solution. Purpose of cpufreq_driver->get() is to get exact frequency from the hardware instead of returning cached frequency that was last requested as that is already present with the core. Hence, this patch forces only IKS to use cpu_last_req_freq and not MP. We will get the frequency from hardware when ->get() is called for MP. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Jon Medhurst <tixy@linaro.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-08-04Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidMark Brown
2013-08-04Merge tag 'v3.10.5' into linux-linaro-lskMark Brown
This is the 3.10.5 stable release
2013-08-04cpufreq / intel_pstate: Change to scale off of max P-stateDirk Brandewie
commit 2134ed4d614349b2b4e8d7bb593baa9179b8dd1e upstream. Change to using max P-state instead of max turbo P-state. This change resolves two issues. On a quiet system intel_pstate can fail to respond to a load change. On CPU SKUs that have a limited number of P-states and no turbo range intel_pstate fails to select the highest available P-state. This change is suitable for stable v3.9+ References: https://bugzilla.kernel.org/show_bug.cgi?id=59481 Reported-and-tested-by: Arjan van de Ven <arjan@linux.intel.com> Reported-and-tested-by: dsmythies@telus.net Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-26Merge branch 'linux-linaro-lsk' into linux-linaro-lsk-androidMark Brown
2013-07-26Merge tag 'v3.10.3' into linux-linaro-lskMark Brown
This is the 3.10.3 stable release
2013-07-25cpufreq: Revert commit 2f7021a8 to fix CPU hotplug regressionSrivatsa S. Bhat
commit e8d05276f236ee6435e78411f62be9714e0b9377 upstream. commit 2f7021a8 "cpufreq: protect 'policy->cpus' from offlining during __gov_queue_work()" caused a regression in CPU hotplug, because it lead to a deadlock between cpufreq governor worker thread and the CPU hotplug writer task. Lockdep splat corresponding to this deadlock is shown below: [ 60.277396] ====================================================== [ 60.277400] [ INFO: possible circular locking dependency detected ] [ 60.277407] 3.10.0-rc7-dbg-01385-g241fd04-dirty #1744 Not tainted [ 60.277411] ------------------------------------------------------- [ 60.277417] bash/2225 is trying to acquire lock: [ 60.277422] ((&(&j_cdbs->work)->work)){+.+...}, at: [<ffffffff810621b5>] flush_work+0x5/0x280 [ 60.277444] but task is already holding lock: [ 60.277449] (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81042d8b>] cpu_hotplug_begin+0x2b/0x60 [ 60.277465] which lock already depends on the new lock. [ 60.277472] the existing dependency chain (in reverse order) is: [ 60.277477] -> #2 (cpu_hotplug.lock){+.+.+.}: [ 60.277490] [<ffffffff810ac6d4>] lock_acquire+0xa4/0x200 [ 60.277503] [<ffffffff815b6157>] mutex_lock_nested+0x67/0x410 [ 60.277514] [<ffffffff81042cbc>] get_online_cpus+0x3c/0x60 [ 60.277522] [<ffffffff814b842a>] gov_queue_work+0x2a/0xb0 [ 60.277532] [<ffffffff814b7891>] cs_dbs_timer+0xc1/0xe0 [ 60.277543] [<ffffffff8106302d>] process_one_work+0x1cd/0x6a0 [ 60.277552] [<ffffffff81063d31>] worker_thread+0x121/0x3a0 [ 60.277560] [<ffffffff8106ae2b>] kthread+0xdb/0xe0 [ 60.277569] [<ffffffff815bb96c>] ret_from_fork+0x7c/0xb0 [ 60.277580] -> #1 (&j_cdbs->timer_mutex){+.+...}: [ 60.277592] [<ffffffff810ac6d4>] lock_acquire+0xa4/0x200 [ 60.277600] [<ffffffff815b6157>] mutex_lock_nested+0x67/0x410 [ 60.277608] [<ffffffff814b785d>] cs_dbs_timer+0x8d/0xe0 [ 60.277616] [<ffffffff8106302d>] process_one_work+0x1cd/0x6a0 [ 60.277624] [<ffffffff81063d31>] worker_thread+0x121/0x3a0 [ 60.277633] [<ffffffff8106ae2b>] kthread+0xdb/0xe0 [ 60.277640] [<ffffffff815bb96c>] ret_from_fork+0x7c/0xb0 [ 60.277649] -> #0 ((&(&j_cdbs->work)->work)){+.+...}: [ 60.277661] [<ffffffff810ab826>] __lock_acquire+0x1766/0x1d30 [ 60.277669] [<ffffffff810ac6d4>] lock_acquire+0xa4/0x200 [ 60.277677] [<ffffffff810621ed>] flush_work+0x3d/0x280 [ 60.277685] [<ffffffff81062d8a>] __cancel_work_timer+0x8a/0x120 [ 60.277693] [<ffffffff81062e53>] cancel_delayed_work_sync+0x13/0x20 [ 60.277701] [<ffffffff814b89d9>] cpufreq_governor_dbs+0x529/0x6f0 [ 60.277709] [<ffffffff814b76a7>] cs_cpufreq_governor_dbs+0x17/0x20 [ 60.277719] [<ffffffff814b5df8>] __cpufreq_governor+0x48/0x100 [ 60.277728] [<ffffffff814b6b80>] __cpufreq_remove_dev.isra.14+0x80/0x3c0 [ 60.277737] [<ffffffff815adc0d>] cpufreq_cpu_callback+0x38/0x4c [ 60.277747] [<ffffffff81071a4d>] notifier_call_chain+0x5d/0x110 [ 60.277759] [<ffffffff81071b0e>] __raw_notifier_call_chain+0xe/0x10 [ 60.277768] [<ffffffff815a0a68>] _cpu_down+0x88/0x330 [ 60.277779] [<ffffffff815a0d46>] cpu_down+0x36/0x50 [ 60.277788] [<ffffffff815a2748>] store_online+0x98/0xd0 [ 60.277796] [<ffffffff81452a28>] dev_attr_store+0x18/0x30 [ 60.277806] [<ffffffff811d9edb>] sysfs_write_file+0xdb/0x150 [ 60.277818] [<ffffffff8116806d>] vfs_write+0xbd/0x1f0 [ 60.277826] [<ffffffff811686fc>] SyS_write+0x4c/0xa0 [ 60.277834] [<ffffffff815bbbbe>] tracesys+0xd0/0xd5 [ 60.277842] other info that might help us debug this: [ 60.277848] Chain exists of: (&(&j_cdbs->work)->work) --> &j_cdbs->timer_mutex --> cpu_hotplug.lock [ 60.277864] Possible unsafe locking scenario: [ 60.277869] CPU0 CPU1 [ 60.277873] ---- ---- [ 60.277877] lock(cpu_hotplug.lock); [ 60.277885] lock(&j_cdbs->timer_mutex); [ 60.277892] lock(cpu_hotplug.lock); [ 60.277900] lock((&(&j_cdbs->work)->work)); [ 60.277907] *** DEADLOCK *** [ 60.277915] 6 locks held by bash/2225: [ 60.277919] #0: (sb_writers#6){.+.+.+}, at: [<ffffffff81168173>] vfs_write+0x1c3/0x1f0 [ 60.277937] #1: (&buffer->mutex){+.+.+.}, at: [<ffffffff811d9e3c>] sysfs_write_file+0x3c/0x150 [ 60.277954] #2: (s_active#61){.+.+.+}, at: [<ffffffff811d9ec3>] sysfs_write_file+0xc3/0x150 [ 60.277972] #3: (x86_cpu_hotplug_driver_mutex){+.+...}, at: [<ffffffff81024cf7>] cpu_hotplug_driver_lock+0x17/0x20 [ 60.277990] #4: (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff815a0d32>] cpu_down+0x22/0x50 [ 60.278007] #5: (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff81042d8b>] cpu_hotplug_begin+0x2b/0x60 [ 60.278023] stack backtrace: [ 60.278031] CPU: 3 PID: 2225 Comm: bash Not tainted 3.10.0-rc7-dbg-01385-g241fd04-dirty #1744 [ 60.278037] Hardware name: Acer Aspire 5741G /Aspire 5741G , BIOS V1.20 02/08/2011 [ 60.278042] ffffffff8204e110 ffff88014df6b9f8 ffffffff815b3d90 ffff88014df6ba38 [ 60.278055] ffffffff815b0a8d ffff880150ed3f60 ffff880150ed4770 3871c4002c8980b2 [ 60.278068] ffff880150ed4748 ffff880150ed4770 ffff880150ed3f60 ffff88014df6bb00 [ 60.278081] Call Trace: [ 60.278091] [<ffffffff815b3d90>] dump_stack+0x19/0x1b [ 60.278101] [<ffffffff815b0a8d>] print_circular_bug+0x2b6/0x2c5 [ 60.278111] [<ffffffff810ab826>] __lock_acquire+0x1766/0x1d30 [ 60.278123] [<ffffffff81067e08>] ? __kernel_text_address+0x58/0x80 [ 60.278134] [<ffffffff810ac6d4>] lock_acquire+0xa4/0x200 [ 60.278142] [<ffffffff810621b5>] ? flush_work+0x5/0x280 [ 60.278151] [<ffffffff810621ed>] flush_work+0x3d/0x280 [ 60.278159] [<ffffffff810621b5>] ? flush_work+0x5/0x280 [ 60.278169] [<ffffffff810a9b14>] ? mark_held_locks+0x94/0x140 [ 60.278178] [<ffffffff81062d77>] ? __cancel_work_timer+0x77/0x120 [ 60.278188] [<ffffffff810a9cbd>] ? trace_hardirqs_on_caller+0xfd/0x1c0 [ 60.278196] [<ffffffff81062d8a>] __cancel_work_timer+0x8a/0x120 [ 60.278206] [<ffffffff81062e53>] cancel_delayed_work_sync+0x13/0x20 [ 60.278214] [<ffffffff814b89d9>] cpufreq_governor_dbs+0x529/0x6f0 [ 60.278225] [<ffffffff814b76a7>] cs_cpufreq_governor_dbs+0x17/0x20 [ 60.278234] [<ffffffff814b5df8>] __cpufreq_governor+0x48/0x100 [ 60.278244] [<ffffffff814b6b80>] __cpufreq_remove_dev.isra.14+0x80/0x3c0 [ 60.278255] [<ffffffff815adc0d>] cpufreq_cpu_callback+0x38/0x4c [ 60.278265] [<ffffffff81071a4d>] notifier_call_chain+0x5d/0x110 [ 60.278275] [<ffffffff81071b0e>] __raw_notifier_call_chain+0xe/0x10 [ 60.278284] [<ffffffff815a0a68>] _cpu_down+0x88/0x330 [ 60.278292] [<ffffffff81024cf7>] ? cpu_hotplug_driver_lock+0x17/0x20 [ 60.278302] [<ffffffff815a0d46>] cpu_down+0x36/0x50 [ 60.278311] [<ffffffff815a2748>] store_online+0x98/0xd0 [ 60.278320] [<ffffffff81452a28>] dev_attr_store+0x18/0x30 [ 60.278329] [<ffffffff811d9edb>] sysfs_write_file+0xdb/0x150 [ 60.278337] [<ffffffff8116806d>] vfs_write+0xbd/0x1f0 [ 60.278347] [<ffffffff81185950>] ? fget_light+0x320/0x4b0 [ 60.278355] [<ffffffff811686fc>] SyS_write+0x4c/0xa0 [ 60.278364] [<ffffffff815bbbbe>] tracesys+0xd0/0xd5 [ 60.280582] smpboot: CPU 1 is now offline The intention of that commit was to avoid warnings during CPU hotplug, which indicated that offline CPUs were getting IPIs from the cpufreq governor's work items. But the real root-cause of that problem was commit a66b2e5 (cpufreq: Preserve sysfs files across suspend/resume) because it totally skipped all the cpufreq callbacks during CPU hotplug in the suspend/resume path, and hence it never actually shut down the cpufreq governor's worker threads during CPU offline in the suspend/resume path. Reflecting back, the reason why we never suspected that commit as the root-cause earlier, was that the original issue was reported with just the halt command and nobody had brought in suspend/resume to the equation. The reason for _that_ in turn, as it turns out, is that earlier halt/shutdown was being done by disabling non-boot CPUs while tasks were frozen, just like suspend/resume.... but commit cf7df378a (reboot: migrate shutdown/reboot to boot cpu) which came somewhere along that very same time changed that logic: shutdown/halt no longer takes CPUs offline. Thus, the test-cases for reproducing the bug were vastly different and thus we went totally off the trail. Overall, it was one hell of a confusion with so many commits affecting each other and also affecting the symptoms of the problems in subtle ways. Finally, now since the original problematic commit (a66b2e5) has been completely reverted, revert this intermediate fix too (2f7021a8), to fix the CPU hotplug deadlock. Phew! Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reported-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Tested-by: Peter Wu <lekensteyn@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>