linux/drivers/cpufreq, branch v3.10.26

intel_pstate: Fail initialization if P-state information is missing

2014-01-09T20:24:23Z

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:[] [] 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: [] call_timer_fn+0x8a/0x310 [] ? call_timer_fn+0x5/0x310 [] ? pid_param_set+0x130/0x130 [] run_timer_softirq+0x234/0x380 [] __do_softirq+0x104/0x430 [] irq_exit+0xcd/0xe0 [] smp_apic_timer_interrupt+0x45/0x60 [] apic_timer_interrupt+0x72/0x80 [] ? vprintk_emit+0x1dd/0x5e0 [] printk+0x67/0x69 [] __cpufreq_add_dev.isra.13+0x883/0x8d0 [] cpufreq_add_dev+0x10/0x20 [] subsys_interface_register+0xb1/0xf0 [] cpufreq_register_driver+0x9f/0x210 [] intel_pstate_init+0x27d/0x3be [] ? mutex_unlock+0xe/0x10 [] ? cpufreq_gov_dbs_init+0x12/0x12 [] do_one_initcall+0xfa/0x1b0 [] ? parse_args+0x225/0x3f0 [] kernel_init_freeable+0x1fc/0x287 [] ? do_early_param+0x88/0x88 [] ? rest_init+0x150/0x150 [] kernel_init+0xe/0x130 [] ret_from_fork+0x7c/0xb0 [] ? 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 [] intel_pstate_timer_func+0x11d/0x2b0 RSP ---[ end trace f166110ed22cc37a ]--- Kernel panic - not syncing: Fatal exception in interrupt Reported-and-tested-by: Kashyap Chamarthy Cc: Josh Boyer Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: highbank-cpufreq: Enable Midway/ECX-2000

2013-12-04T18:57:18Z

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 Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq / intel_pstate: Fix max_perf_pct on resume

2013-11-13T03:05:30Z

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 Signed-off-by: Dirk Brandewie Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: rename ignore_nice as ignore_nice_load

2013-08-15T05:59:06Z

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 Signed-off-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: loongson2: fix regression related to clock management

2013-08-15T05:59:06Z

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 Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: Fix cpufreq driver module refcount balance after suspend/resume

2013-08-12T01:35:24Z

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 Signed-off-by: Rafael J. Wysocki Reviewed-by: Srivatsa S. Bhat Signed-off-by: Greg Kroah-Hartman

cpufreq / intel_pstate: Change to scale off of max P-state

2013-08-04T08:50:51Z

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 Reported-and-tested-by: dsmythies@telus.net Signed-off-by: Dirk Brandewie Acked-by: Viresh Kumar Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: Revert commit 2f7021a8 to fix CPU hotplug regression

2013-07-25T21:07:23Z

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: [] flush_work+0x5/0x280 [ 60.277444] but task is already holding lock: [ 60.277449] (cpu_hotplug.lock){+.+.+.}, at: [] 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] [] lock_acquire+0xa4/0x200 [ 60.277503] [] mutex_lock_nested+0x67/0x410 [ 60.277514] [] get_online_cpus+0x3c/0x60 [ 60.277522] [] gov_queue_work+0x2a/0xb0 [ 60.277532] [] cs_dbs_timer+0xc1/0xe0 [ 60.277543] [] process_one_work+0x1cd/0x6a0 [ 60.277552] [] worker_thread+0x121/0x3a0 [ 60.277560] [] kthread+0xdb/0xe0 [ 60.277569] [] ret_from_fork+0x7c/0xb0 [ 60.277580] -> #1 (&j_cdbs->timer_mutex){+.+...}: [ 60.277592] [] lock_acquire+0xa4/0x200 [ 60.277600] [] mutex_lock_nested+0x67/0x410 [ 60.277608] [] cs_dbs_timer+0x8d/0xe0 [ 60.277616] [] process_one_work+0x1cd/0x6a0 [ 60.277624] [] worker_thread+0x121/0x3a0 [ 60.277633] [] kthread+0xdb/0xe0 [ 60.277640] [] ret_from_fork+0x7c/0xb0 [ 60.277649] -> #0 ((&(&j_cdbs->work)->work)){+.+...}: [ 60.277661] [] __lock_acquire+0x1766/0x1d30 [ 60.277669] [] lock_acquire+0xa4/0x200 [ 60.277677] [] flush_work+0x3d/0x280 [ 60.277685] [] __cancel_work_timer+0x8a/0x120 [ 60.277693] [] cancel_delayed_work_sync+0x13/0x20 [ 60.277701] [] cpufreq_governor_dbs+0x529/0x6f0 [ 60.277709] [] cs_cpufreq_governor_dbs+0x17/0x20 [ 60.277719] [] __cpufreq_governor+0x48/0x100 [ 60.277728] [] __cpufreq_remove_dev.isra.14+0x80/0x3c0 [ 60.277737] [] cpufreq_cpu_callback+0x38/0x4c [ 60.277747] [] notifier_call_chain+0x5d/0x110 [ 60.277759] [] __raw_notifier_call_chain+0xe/0x10 [ 60.277768] [] _cpu_down+0x88/0x330 [ 60.277779] [] cpu_down+0x36/0x50 [ 60.277788] [] store_online+0x98/0xd0 [ 60.277796] [] dev_attr_store+0x18/0x30 [ 60.277806] [] sysfs_write_file+0xdb/0x150 [ 60.277818] [] vfs_write+0xbd/0x1f0 [ 60.277826] [] SyS_write+0x4c/0xa0 [ 60.277834] [] 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: [] vfs_write+0x1c3/0x1f0 [ 60.277937] #1: (&buffer->mutex){+.+.+.}, at: [] sysfs_write_file+0x3c/0x150 [ 60.277954] #2: (s_active#61){.+.+.+}, at: [] sysfs_write_file+0xc3/0x150 [ 60.277972] #3: (x86_cpu_hotplug_driver_mutex){+.+...}, at: [] cpu_hotplug_driver_lock+0x17/0x20 [ 60.277990] #4: (cpu_add_remove_lock){+.+.+.}, at: [] cpu_down+0x22/0x50 [ 60.278007] #5: (cpu_hotplug.lock){+.+.+.}, at: [] 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] [] dump_stack+0x19/0x1b [ 60.278101] [] print_circular_bug+0x2b6/0x2c5 [ 60.278111] [] __lock_acquire+0x1766/0x1d30 [ 60.278123] [] ? __kernel_text_address+0x58/0x80 [ 60.278134] [] lock_acquire+0xa4/0x200 [ 60.278142] [] ? flush_work+0x5/0x280 [ 60.278151] [] flush_work+0x3d/0x280 [ 60.278159] [] ? flush_work+0x5/0x280 [ 60.278169] [] ? mark_held_locks+0x94/0x140 [ 60.278178] [] ? __cancel_work_timer+0x77/0x120 [ 60.278188] [] ? trace_hardirqs_on_caller+0xfd/0x1c0 [ 60.278196] [] __cancel_work_timer+0x8a/0x120 [ 60.278206] [] cancel_delayed_work_sync+0x13/0x20 [ 60.278214] [] cpufreq_governor_dbs+0x529/0x6f0 [ 60.278225] [] cs_cpufreq_governor_dbs+0x17/0x20 [ 60.278234] [] __cpufreq_governor+0x48/0x100 [ 60.278244] [] __cpufreq_remove_dev.isra.14+0x80/0x3c0 [ 60.278255] [] cpufreq_cpu_callback+0x38/0x4c [ 60.278265] [] notifier_call_chain+0x5d/0x110 [ 60.278275] [] __raw_notifier_call_chain+0xe/0x10 [ 60.278284] [] _cpu_down+0x88/0x330 [ 60.278292] [] ? cpu_hotplug_driver_lock+0x17/0x20 [ 60.278302] [] cpu_down+0x36/0x50 [ 60.278311] [] store_online+0x98/0xd0 [ 60.278320] [] dev_attr_store+0x18/0x30 [ 60.278329] [] sysfs_write_file+0xdb/0x150 [ 60.278337] [] vfs_write+0xbd/0x1f0 [ 60.278347] [] ? fget_light+0x320/0x4b0 [ 60.278355] [] SyS_write+0x4c/0xa0 [ 60.278364] [] 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 Reported-by: Bartlomiej Zolnierkiewicz Signed-off-by: Srivatsa S. Bhat Tested-by: Peter Wu Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: Revert commit a66b2e to fix suspend/resume regression

2013-07-25T21:07:23Z

commit aae760ed21cd690fe8a6db9f3a177ad55d7e12ab upstream. commit a66b2e (cpufreq: Preserve sysfs files across suspend/resume) has unfortunately caused several things in the cpufreq subsystem to break subtly after a suspend/resume cycle. The intention of that patch was to retain the file permissions of the cpufreq related sysfs files across suspend/resume. To achieve that, the commit completely removed the calls to cpufreq_add_dev() and __cpufreq_remove_dev() during suspend/resume transitions. But the problem is that those functions do 2 kinds of things: 1. Low-level initialization/tear-down that are critical to the correct functioning of cpufreq-core. 2. Kobject and sysfs related initialization/teardown. Ideally we should have reorganized the code to cleanly separate these two responsibilities, and skipped only the sysfs related parts during suspend/resume. Since we skipped the entire callbacks instead (which also included some CPU and cpufreq-specific critical components), cpufreq subsystem started behaving erratically after suspend/resume. So revert the commit to fix the regression. We'll revisit and address the original goal of that commit separately, since it involves quite a bit of careful code reorganization and appears to be non-trivial. (While reverting the commit, note that another commit f51e1eb (cpufreq: Fix cpufreq regression after suspend/resume) already reverted part of the original set of changes. So revert only the remaining ones). Signed-off-by: Srivatsa S. Bhat Acked-by: Viresh Kumar Tested-by: Paul Bolle Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

cpufreq: Fix cpufreq regression after suspend/resume

2013-07-13T18:42:27Z

commit f51e1eb63d9c28cec188337ee656a13be6980cfd upstream. Toralf Förster reported that the cpufreq ondemand governor behaves erratically (doesn't scale well) after a suspend/resume cycle. The problem was that the cpufreq subsystem's idea of the cpu frequencies differed from the actual frequencies set in the hardware after a suspend/resume cycle. Toralf bisected the problem to commit a66b2e5 (cpufreq: Preserve sysfs files across suspend/resume). Among other (harmless) things, that commit skipped the call to cpufreq_update_policy() in the resume path. But cpufreq_update_policy() plays an important role during resume, because it is responsible for checking if the BIOS changed the cpu frequencies behind our back and resynchronize the cpufreq subsystem's knowledge of the cpu frequencies, and update them accordingly. So, restore the call to cpufreq_update_policy() in the resume path to fix the cpufreq regression. Reported-and-tested-by: Toralf Förster Signed-off-by: Srivatsa S. Bhat Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman