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* cpufreq: Fix cpufreq driver module refcount balance after suspend/resumeRafael J. Wysocki2013-07-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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> Cc: 3.10+ <stable@vger.kernel.org>
* Merge tag 'pm+acpi-3.11-rc2' of ↵Linus Torvalds2013-07-19
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI fixes from Rafael Wysocki: "These are fixes collected over the last week, most importnatly two cpufreq reverts fixing regressions introduced in 3.10, an autoseelp fix preventing systems using it from crashing during shutdown and two ACPI scan fixes related to hotplug. Specifics: - Two cpufreq commits from the 3.10 cycle introduced regressions. The first of them was buggy (it did way much more than it needed to do) and the second one attempted to fix an issue introduced by the first one. Fixes from Srivatsa S Bhat revert both. - If autosleep triggers during system shutdown and the shutdown callbacks of some device drivers have been called already, it may crash the system. Fix from Liu Shuo prevents that from happening by making try_to_suspend() check system_state. - The ACPI memory hotplug driver doesn't clear its driver_data on errors which may cause a NULL poiter dereference to happen later. Fix from Toshi Kani. - The ACPI namespace scanning code should not try to attach scan handlers to device objects that have them already, which may confuse things quite a bit, and it should rescan the whole namespace branch starting at the given node after receiving a bus check notify event even if the device at that particular node has been discovered already. Fixes from Rafael J Wysocki. - New ACPI video blacklist entry for a system whose initial backlight setting from the BIOS doesn't make sense. From Lan Tianyu. - Garbage string output avoindance for ACPI PNP from Liu Shuo. - Two Kconfig fixes for issues introduced recently in the s3c24xx cpufreq driver (when moving the driver to drivers/cpufreq) from Paul Bolle. - Trivial comment fix in pm_wakeup.h from Chanwoo Choi" * tag 'pm+acpi-3.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / video: ignore BIOS initial backlight value for Fujitsu E753 PNP / ACPI: avoid garbage in resource name cpufreq: Revert commit 2f7021a8 to fix CPU hotplug regression cpufreq: s3c24xx: fix "depends on ARM_S3C24XX" in Kconfig cpufreq: s3c24xx: rename CONFIG_CPU_FREQ_S3C24XX_DEBUGFS PM / Sleep: Fix comment typo in pm_wakeup.h PM / Sleep: avoid 'autosleep' in shutdown progress cpufreq: Revert commit a66b2e to fix suspend/resume regression ACPI / memhotplug: Fix a stale pointer in error path ACPI / scan: Always call acpi_bus_scan() for bus check notifications ACPI / scan: Do not try to attach scan handlers to devices having them
| * cpufreq: Revert commit a66b2e to fix suspend/resume regressionSrivatsa S. Bhat2013-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Paul Bolle <pebolle@tiscali.nl> Cc: 3.10+ <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | cpufreq: delete __cpuinit usage from all cpufreq filesPaul Gortmaker2013-07-14
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. This removes all the drivers/cpufreq uses of the __cpuinit macros from all C files. [1] https://lkml.org/lkml/2013/5/20/589 [v2: leave 2nd lines of args misaligned as requested by Viresh] Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: cpufreq@vger.kernel.org Cc: linux-pm@vger.kernel.org Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* cpufreq: Fix serialization of frequency transitionsViresh Kumar2013-07-04
| | | | | | | | | | | | | | | | | | Commit 7c30ed ("cpufreq: make sure frequency transitions are serialized") interacts poorly with systems that have a single core freqency for all cores. On such systems we have a single policy for all cores with several CPUs. When we do a frequency transition the governor calls the pre and post change notifiers which causes cpufreq_notify_transition() per CPU. Since the policy is the same for all of them all CPUs after the first and the warnings added are generated by checking a per-policy flag the warnings will be triggered for all cores after the first. Fix this by allowing notifier to be called for n times. Where n is the number of cpus in policy->cpus. Reported-and-tested-by: Mark Brown <broonie@linaro.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* acpi-cpufreq: Add new sysfs attribute freqdomain_cpusLan Tianyu2013-06-27
| | | | | | | | | | | | | | | | | | | | | Commits fcf8058 (cpufreq: Simplify cpufreq_add_dev()) and aa77a52 (cpufreq: acpi-cpufreq: Don't set policy->related_cpus from .init()) changed the contents of the "related_cpus" sysfs attribute on systems where acpi-cpufreq is used and user space can't get the list of CPUs which are in the same hardware coordination CPU domain (provided by the ACPI AML method _PSD) via "related_cpus" any more. To make up for that loss add a new sysfs attribute "freqdomian_cpus" for the acpi-cpufreq driver which exposes the list of CPUs in the same domain regardless of whether it is coordinated by hardware or software. [rjw: Changelog, documentation] References: https://bugzilla.kernel.org/show_bug.cgi?id=58761 Reported-by: Jean-Philippe Halimi <jean-philippe.halimi@exascale-computing.eu> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: make sure frequency transitions are serializedViresh Kumar2013-06-27
| | | | | | | | | | | | | | | Whenever we are changing frequency of a cpu, we are calling PRECHANGE and POSTCHANGE notifiers. They must be serialized. i.e. PRECHANGE or POSTCHANGE shouldn't be called twice contiguously. This can happen due to bugs in users of __cpufreq_driver_target() or actual cpufreq drivers who are sending these notifiers. This patch adds some protection against this. Now, we keep track of the last transaction and see if something went wrong. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: make __cpufreq_notify_transition() staticViresh Kumar2013-06-20
| | | | | | | | __cpufreq_notify_transition() is used only in cpufreq.c, make it static. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Fix minor formatting issuesViresh Kumar2013-06-20
| | | | | | | | | | | | | | | | There were a few noticeable formatting issues in core cpufreq code. This cleans them up to make code look better. The changes include: - Whitespace cleanup. - Rearrangements of code. - Multiline comments fixes. - Formatting changes to fit 80 columns. Copyright information in cpufreq.c is also updated to include my name for 2013. [rjw: Changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Fix governor start/stop race conditionXiaoguang Chen2013-06-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Cpufreq governors' stop and start operations should be carried out in sequence. Otherwise, there will be unexpected behavior, like in the example below. Suppose there are 4 CPUs and policy->cpu=CPU0, CPU1/2/3 are linked to CPU0. The normal sequence is: 1) Current governor is userspace. An application tries to set the governor to ondemand. It will call __cpufreq_set_policy() in which it will stop the userspace governor and then start the ondemand governor. 2) Current governor is userspace. The online of CPU3 runs on CPU0. It will call cpufreq_add_policy_cpu() in which it will first stop the userspace governor, and then start it again. If the sequence of the above two cases interleaves, it becomes: 1) Application stops userspace governor 2) Hotplug stops userspace governor which is a problem, because the governor shouldn't be stopped twice in a row. What happens next is: 3) Application starts ondemand governor 4) Hotplug starts a governor In step 4, the hotplug is supposed to start the userspace governor, but now the governor has been changed by the application to ondemand, so the ondemand governor is started once again, which is incorrect. The solution is to prevent policy governors from being stopped multiple times in a row. A governor should only be stopped once for one policy. After it has been stopped, no more governor stop operations should be executed. Also add a mutex to serialize governor operations. [rjw: Changelog. And you owe me a beverage of my choice.] Signed-off-by: Xiaoguang Chen <chenxg@marvell.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: remove unnecessary cpufreq_cpu_{get|put}() callsViresh Kumar2013-06-04
| | | | | | | | | | | | struct cpufreq_policy is already passed as argument to some routines like: __cpufreq_driver_getavg() and so we don't really need to do cpufreq_cpu_get() before and cpufreq_cpu_put() in them to get a policy structure. Remove them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Don't create empty /sys/devices/system/cpu/cpufreq directoryViresh Kumar2013-05-27
| | | | | | | | | | | | | When we don't have any file in cpu/cpufreq directory we shouldn't create it. Specially with the introduction of per-policy governor instance patchset, even governors are moved to cpu/cpu*/cpufreq/governor-name directory and so this directory is just not required. Lets have it only when required. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Move get_cpu_idle_time() to cpufreq.cViresh Kumar2013-05-27
| | | | | | | | | | Governors other than ondemand and conservative can also use get_cpu_idle_time() and they aren't required to compile cpufreq_governor.c. So, move these independent routines to cpufreq.c instead. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: governors: Move get_governor_parent_kobj() to cpufreq.cViresh Kumar2013-05-27
| | | | | | | | | | | | | get_governor_parent_kobj() can be used by any governor, generic cpufreq governors or platform specific ones and so must be present in cpufreq.c instead of cpufreq_governor.c. This patch moves it to cpufreq.c. This also adds EXPORT_SYMBOL_GPL(get_governor_parent_kobj) so that modules can use this function too. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Add EXPORT_SYMBOL_GPL for have_governor_per_policyViresh Kumar2013-05-27
| | | | | | | | This patch adds: EXPORT_SYMBOL_GPL(have_governor_per_policy), so that this routine can be used by modules too. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Drop rwsem lock around CPUFREQ_GOV_POLICY_EXITViresh Kumar2013-05-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the rwsem lock around __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT), we get circular dependency when we call sysfs_remove_group(). ====================================================== [ INFO: possible circular locking dependency detected ] 3.9.0-rc7+ #15 Not tainted ------------------------------------------------------- cat/2387 is trying to acquire lock: (&per_cpu(cpu_policy_rwsem, cpu)){+++++.}, at: [<c02f6179>] lock_policy_rwsem_read+0x25/0x34 but task is already holding lock: (s_active#41){++++.+}, at: [<c00f9bf7>] sysfs_read_file+0x4f/0xcc which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (s_active#41){++++.+}: [<c0055a79>] lock_acquire+0x61/0xbc [<c00fabf1>] sysfs_addrm_finish+0xc1/0x128 [<c00f9819>] sysfs_hash_and_remove+0x35/0x64 [<c00fbe6f>] remove_files.isra.0+0x1b/0x24 [<c00fbea5>] sysfs_remove_group+0x2d/0xa8 [<c02f9a0b>] cpufreq_governor_interactive+0x13b/0x35c [<c02f61df>] __cpufreq_governor+0x2b/0x8c [<c02f6579>] __cpufreq_set_policy+0xa9/0xf8 [<c02f6b75>] store_scaling_governor+0x61/0x100 [<c02f6f4d>] store+0x39/0x60 [<c00f9b81>] sysfs_write_file+0xed/0x114 [<c00b3fd1>] vfs_write+0x65/0xd8 [<c00b424b>] sys_write+0x2f/0x50 [<c000cdc1>] ret_fast_syscall+0x1/0x52 -> #0 (&per_cpu(cpu_policy_rwsem, cpu)){+++++.}: [<c0055253>] __lock_acquire+0xef3/0x13dc [<c0055a79>] lock_acquire+0x61/0xbc [<c03ee1f5>] down_read+0x25/0x30 [<c02f6179>] lock_policy_rwsem_read+0x25/0x34 [<c02f6edd>] show+0x21/0x58 [<c00f9c0f>] sysfs_read_file+0x67/0xcc [<c00b40a7>] vfs_read+0x63/0xd8 [<c00b41fb>] sys_read+0x2f/0x50 [<c000cdc1>] ret_fast_syscall+0x1/0x52 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(s_active#41); lock(&per_cpu(cpu_policy_rwsem, cpu)); lock(s_active#41); lock(&per_cpu(cpu_policy_rwsem, cpu)); *** DEADLOCK *** 2 locks held by cat/2387: #0: (&buffer->mutex){+.+.+.}, at: [<c00f9bcd>] sysfs_read_file+0x25/0xcc #1: (s_active#41){++++.+}, at: [<c00f9bf7>] sysfs_read_file+0x4f/0xcc stack backtrace: [<c0011d55>] (unwind_backtrace+0x1/0x9c) from [<c03e9a09>] (print_circular_bug+0x19d/0x1e8) [<c03e9a09>] (print_circular_bug+0x19d/0x1e8) from [<c0055253>] (__lock_acquire+0xef3/0x13dc) [<c0055253>] (__lock_acquire+0xef3/0x13dc) from [<c0055a79>] (lock_acquire+0x61/0xbc) [<c0055a79>] (lock_acquire+0x61/0xbc) from [<c03ee1f5>] (down_read+0x25/0x30) [<c03ee1f5>] (down_read+0x25/0x30) from [<c02f6179>] (lock_policy_rwsem_read+0x25/0x34) [<c02f6179>] (lock_policy_rwsem_read+0x25/0x34) from [<c02f6edd>] (show+0x21/0x58) [<c02f6edd>] (show+0x21/0x58) from [<c00f9c0f>] (sysfs_read_file+0x67/0xcc) [<c00f9c0f>] (sysfs_read_file+0x67/0xcc) from [<c00b40a7>] (vfs_read+0x63/0xd8) [<c00b40a7>] (vfs_read+0x63/0xd8) from [<c00b41fb>] (sys_read+0x2f/0x50) [<c00b41fb>] (sys_read+0x2f/0x50) from [<c000cdc1>] (ret_fast_syscall+0x1/0x52) This lock isn't required while calling __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT). Remove it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Preserve sysfs files across suspend/resumeSrivatsa S. Bhat2013-05-15
| | | | | | | | | | | | | | | | | | | | | | The file permissions of cpufreq per-cpu sysfs files are not preserved across suspend/resume because we internally go through the CPU Hotplug path which reinitializes the file permissions on CPU online. But the user is not supposed to know that we are using CPU hotplug internally within suspend/resume (IOW, the kernel should not silently wreck the user-set file permissions across a suspend cycle). Therefore, we need to preserve the file permissions as they are across suspend/resume. The simplest way to achieve that is to just not touch the sysfs files at all - ie., just ignore the CPU hotplug notifications in the suspend/resume path (_FROZEN) in the cpufreq hotplug callback. Reported-by: Robert Jarzmik <robert.jarzmik@intel.com> Reported-by: Durgadoss R <durgadoss.r@intel.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Issue CPUFREQ_GOV_POLICY_EXIT notifier before dropping policy refcountViresh Kumar2013-05-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We must call __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT) before calling cpufreq_cpu_put(data), so that policy kobject have valid fields. Otherwise, removing last online cpu of policy->cpus causes this crash for ondemand/conservative governor. [<c00fb076>] (sysfs_find_dirent+0xe/0xa8) from [<c00fb1bd>] (sysfs_get_dirent+0x21/0x58) [<c00fb1bd>] (sysfs_get_dirent+0x21/0x58) from [<c00fc259>] (sysfs_remove_group+0x85/0xbc) [<c00fc259>] (sysfs_remove_group+0x85/0xbc) from [<c02faad9>] (cpufreq_governor_dbs+0x369/0x4a0) [<c02faad9>] (cpufreq_governor_dbs+0x369/0x4a0) from [<c02f66d7>] (__cpufreq_governor+0x2b/0x8c) [<c02f66d7>] (__cpufreq_governor+0x2b/0x8c) from [<c02f6893>] (__cpufreq_remove_dev.isra.12+0x15b/0x250) [<c02f6893>] (__cpufreq_remove_dev.isra.12+0x15b/0x250) from [<c03e91c7>] (cpufreq_cpu_callback+0x2f/0x3c) [<c03e91c7>] (cpufreq_cpu_callback+0x2f/0x3c) from [<c0036fe1>] (notifier_call_chain+0x45/0x54) [<c0036fe1>] (notifier_call_chain+0x45/0x54) from [<c001e611>] (__cpu_notify+0x1d/0x34) [<c001e611>] (__cpu_notify+0x1d/0x34) from [<c03e5833>] (_cpu_down+0x63/0x1ac) [<c03e5833>] (_cpu_down+0x63/0x1ac) from [<c03e5997>] (cpu_down+0x1b/0x30) [<c03e5997>] (cpu_down+0x1b/0x30) from [<c03e60eb>] (store_online+0x27/0x54) [<c03e60eb>] (store_online+0x27/0x54) from [<c0295629>] (dev_attr_store+0x11/0x18) [<c0295629>] (dev_attr_store+0x11/0x18) from [<c00f9edd>] (sysfs_write_file+0xed/0x114) [<c00f9edd>] (sysfs_write_file+0xed/0x114) from [<c00b42a9>] (vfs_write+0x65/0xd8) [<c00b42a9>] (vfs_write+0x65/0xd8) from [<c00b4523>] (sys_write+0x2f/0x50) [<c00b4523>] (sys_write+0x2f/0x50) from [<c000cdc1>] (ret_fast_syscall+0x1/0x52) Of course this only impacted drivers which have have_governor_per_policy set to true. i.e. big LITTLE cpufreq driver. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Revert incorrect commit 5800043Rafael J. Wysocki2013-04-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 5800043 (cpufreq: convert cpufreq_driver to using RCU) causes the following call trace to be spit on boot: BUG: sleeping function called from invalid context at /scratch/rafael/work/linux-pm/mm/slab.c:3179 in_atomic(): 0, irqs_disabled(): 0, pid: 292, name: systemd-udevd 2 locks held by systemd-udevd/292: #0: (subsys mutex){+.+.+.}, at: [<ffffffff8146851a>] subsys_interface_register+0x4a/0xe0 #1: (rcu_read_lock){.+.+.+}, at: [<ffffffff81538210>] cpufreq_add_dev_interface+0x60/0x5e0 Pid: 292, comm: systemd-udevd Not tainted 3.9.0-rc8+ #323 Call Trace: [<ffffffff81072c90>] __might_sleep+0x140/0x1f0 [<ffffffff811581c2>] kmem_cache_alloc+0x42/0x2b0 [<ffffffff811e7179>] sysfs_new_dirent+0x59/0x130 [<ffffffff811e63cb>] sysfs_add_file_mode+0x6b/0x110 [<ffffffff81538210>] ? cpufreq_add_dev_interface+0x60/0x5e0 [<ffffffff810a3254>] ? __lock_is_held+0x54/0x80 [<ffffffff811e647d>] sysfs_add_file+0xd/0x10 [<ffffffff811e6541>] sysfs_create_file+0x21/0x30 [<ffffffff81538280>] cpufreq_add_dev_interface+0xd0/0x5e0 [<ffffffff81538210>] ? cpufreq_add_dev_interface+0x60/0x5e0 [<ffffffffa000337f>] ? acpi_processor_get_platform_limit+0x32/0xbb [processor] [<ffffffffa022f540>] ? do_drv_write+0x70/0x70 [acpi_cpufreq] [<ffffffff810a3254>] ? __lock_is_held+0x54/0x80 [<ffffffff8106c97e>] ? up_read+0x1e/0x40 [<ffffffff8106e632>] ? __blocking_notifier_call_chain+0x72/0xc0 [<ffffffff81538dbd>] cpufreq_add_dev+0x62d/0xae0 [<ffffffff815389b8>] ? cpufreq_add_dev+0x228/0xae0 [<ffffffff81468569>] subsys_interface_register+0x99/0xe0 [<ffffffffa014d000>] ? 0xffffffffa014cfff [<ffffffff81535d5d>] cpufreq_register_driver+0x9d/0x200 [<ffffffffa014d000>] ? 0xffffffffa014cfff [<ffffffffa014d0e9>] acpi_cpufreq_init+0xe9/0x1000 [acpi_cpufreq] [<ffffffff810002fa>] do_one_initcall+0x11a/0x170 [<ffffffff810b4b87>] load_module+0x1cf7/0x2920 [<ffffffff81322580>] ? ddebug_proc_open+0xb0/0xb0 [<ffffffff816baee0>] ? retint_restore_args+0xe/0xe [<ffffffff810b5887>] sys_init_module+0xd7/0x120 [<ffffffff816bb6d2>] system_call_fastpath+0x16/0x1b which is quite obvious, because that commit put (multiple instances of) sysfs_create_file() under rcu_read_lock()/rcu_read_unlock(), although sysfs_create_file() may cause memory to be allocated with GFP_KERNEL and that may sleep, which is not permitted in RCU read critical section. Revert the buggy commit altogether along with some changes on top of it. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Don't call __cpufreq_governor() for drivers without target()Viresh Kumar2013-04-21
| | | | | | | | | | | | | | Some cpufreq drivers implement their own governor and so don't need us to call generic governors interface via __cpufreq_governor(). Few recent commits haven't obeyed this law well and we saw some regressions. This patch is an attempt to fix the above issue. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com> Tested-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Call __cpufreq_governor() with correct policy->cpus maskViresh Kumar2013-04-11
| | | | | | | | | | | | | | | | | | | __cpufreq_governor() must be called with a correct policy->cpus mask. In __cpufreq_remove_dev() we initially clear policy->cpus with cpumask_clear_cpu() and then call __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT). If the governor is doing some per-cpu stuff in EXIT callback, this can create uncertain behavior. Generic governors in drivers/cpufreq/ doesn't do any per-cpu stuff in EXIT callback and so we don't face any issues currently. But its better to keep the code clean, so we don't face any issues in future. Now, we call cpumask_clear_cpu() only when multiple cpus are managed by policy. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: convert cpufreq_driver to using RCUNathan Zimmer2013-04-10
| | | | | | | | | | | | | | We eventually would like to remove the rwlock cpufreq_driver_lock or convert it back to a spinlock and protect the read sections with RCU. The first step in that direction is to make cpufreq_driver use RCU. I don't see an easy wasy to protect the cpufreq_cpu_data structure with RCU, so I am leaving it with the rwlock for now since under certain configs __cpufreq_cpu_get is a hot spot with 256+ cores. [rjw: Subject, changelog, white space] Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Notify all policy->cpus in cpufreq_notify_transition()Viresh Kumar2013-04-02
| | | | | | | | | | | | | | | | policy->cpus contains all online cpus that have single shared clock line. And their frequencies are always updated together. Many SMP system's cpufreq drivers take care of this in individual drivers but the best place for this code is in cpufreq core. This patch modifies cpufreq_notify_transition() to notify frequency change for all cpus in policy->cpus and hence updates all users of this API. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Stephen Warren <swarren@nvidia.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: governor: Implement per policy instances of governorsViresh Kumar2013-03-31
| | | | | | | | | | | | | | | | | | | | | | Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch uses the infrastructure provided by earlier patch and implements init/exit routines for ondemand and conservative governors. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Add per policy governor-init/exit infrastructureViresh Kumar2013-03-31
| | | | | | | | | | | | | | | | | | | | | | | Currently, there can't be multiple instances of single governor_type. If we have a multi-package system, where we have multiple instances of struct policy (per package), we can't have multiple instances of same governor. i.e. We can't have multiple instances of ondemand governor for multiple packages. Governors directory in sysfs is created at /sys/devices/system/cpu/cpufreq/ governor-name/. Which again reflects that there can be only one instance of a governor_type in the system. This is a bottleneck for multicluster system, where we want different packages to use same governor type, but with different tunables. This patch is inclined towards providing this infrastructure. Because we are required to allocate governor's resources dynamically now, we must do it at policy creation and end. And so got CPUFREQ_GOV_POLICY_INIT/EXIT. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Convert the cpufreq_driver_lock to a rwlockNathan Zimmer2013-03-31
| | | | | | | | | This eliminates the contention I am seeing in __cpufreq_cpu_get. It also nicely stages the lock to be replaced by the rcu. Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* Merge branch 'pm-cpufreq'Rafael J. Wysocki2013-02-15
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-cpufreq: (55 commits) cpufreq / intel_pstate: Fix 32 bit build cpufreq: conservative: Fix typos in comments cpufreq: ondemand: Fix typos in comments cpufreq: exynos: simplify .init() for setting policy->cpus cpufreq: kirkwood: Add a cpufreq driver for Marvell Kirkwood SoCs cpufreq/x86: Add P-state driver for sandy bridge. cpufreq_stats: do not remove sysfs files if frequency table is not present cpufreq: Do not track governor name for scaling drivers with internal governors. cpufreq: Only call cpufreq_out_of_sync() for driver that implement cpufreq_driver.target() cpufreq: Retrieve current frequency from scaling drivers with internal governors cpufreq: Fix locking issues cpufreq: Create a macro for unlock_policy_rwsem{read,write} cpufreq: Remove unused HOTPLUG_CPU code cpufreq: governors: Fix WARN_ON() for multi-policy platforms cpufreq: ondemand: Replace down_differential tuner with adj_up_threshold cpufreq / stats: Get rid of CPUFREQ_STATDEVICE_ATTR cpufreq: Don't check cpu_online(policy->cpu) cpufreq: add imx6q-cpufreq driver cpufreq: Don't remove sysfs link for policy->cpu cpufreq: Remove unnecessary use of policy->shared_type ...
| * cpufreq: Do not track governor name for scaling drivers with internal governors.Dirk Brandewie2013-02-09
| | | | | | | | | | | | | | | | | | | | | | Scaling drivers that implement internal governors do not have governor structures assocaited with them. Only track the name of the governor associated with the CPU if the driver does not implement cpufreq_driver.setpolicy() 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>
| * cpufreq: Only call cpufreq_out_of_sync() for driver that implement ↵Dirk Brandewie2013-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpufreq_driver.target() Scaling drivers that implement cpufreq_driver.setpolicy() have internal governors that do not signal changes via cpufreq_notify_transition() so the frequncy in the policy will almost certainly be different than the current frequncy. Only call cpufreq_out_of_sync() when the underlying driver implements cpufreq_driver.target() 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>
| * cpufreq: Retrieve current frequency from scaling drivers with internal governorsDirk Brandewie2013-02-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Scaling drivers that implement the cpufreq_driver.setpolicy() versus the cpufreq_driver.target() interface do not set policy->cur. Normally policy->cur is set during the call to cpufreq_driver.target() when the frequnecy request is made by the governor. If the scaling driver implements cpufreq_driver.setpolicy() and cpufreq_driver.get() interfaces use cpufreq_driver.get() to retrieve the current frequency. 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>
| * cpufreq: Fix locking issuesViresh Kumar2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | cpufreq core uses two locks: - cpufreq_driver_lock: General lock for driver and cpufreq_cpu_data array. - cpu_policy_rwsemfix locking: per CPU reader-writer semaphore designed to cure all cpufreq/hotplug/workqueue/etc related lock issues. These locks were not used properly and are placed against their principle (present before their definition) at various places. This patch is an attempt to fix their use. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Create a macro for unlock_policy_rwsem{read,write}Viresh Kumar2013-02-08
| | | | | | | | | | | | | | | | On the lines of macro: lock_policy_rwsem, we can create another macro for unlock_policy_rwsem. Lets do it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Remove unused HOTPLUG_CPU codeViresh Kumar2013-02-08
| | | | | | | | | | | | | | | | Because the sibling cpu of any online cpu is identified very early in cpufreq_add_dev(), below code is never executed. And so can be removed. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: governors: Fix WARN_ON() for multi-policy platformsViresh Kumar2013-02-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On multi-policy systems there is a single instance of governor for both the policies (if same governor is chosen for both policies). With the code update from following patches: 8eeed09 cpufreq: governors: Get rid of dbs_data->enable field b394058 cpufreq: governors: Reset tunables only for cpufreq_unregister_governor() We are creating/removing sysfs directory of governor for for every call to GOV_START and STOP. This would fail for multi-policy system as there is a per-policy call to START/STOP. This patch reuses the governor->initialized variable to detect total users of governor. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Don't check cpu_online(policy->cpu)Viresh Kumar2013-02-08
| | | | | | | | | | | | | | | | policy->cpu or cpus in policy->cpus can't be offline anymore. And so we don't need to check if they are online or not. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Don't remove sysfs link for policy->cpuViresh Kumar2013-02-05
| | | | | | | | | | | | | | | | | | | | | | | | "cpufreq" directory in policy->cpu is never created using sysfs_create_link(), but using kobject_init_and_add(). And so we shouldn't call sysfs_remove_link() for policy->cpu(). sysfs stuff for policy->cpu is automatically removed when we call kobject_put() for dying policy. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Dirk Brandewie <dirk.brandewie@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: governors: Reset tunables only for cpufreq_unregister_governor()Viresh Kumar2013-02-01
| | | | | | | | | | | | | | | | | | | | Currently, whenever governor->governor() is called for CPUFRREQ_GOV_START event we reset few tunables of governor. Which isn't correct, as this routine is called for every cpu hot-[un]plugging event. We should actually be resetting these only when the governor module is removed and re-installed. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Simplify cpufreq_add_dev()Viresh Kumar2013-02-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently cpufreq_add_dev() firsts allocates policy, calls driver->init() and then checks if this CPU is already managed or not. And if it is already managed, its policy is freed. We can save all this if we somehow know that CPU is managed or not in advance. policy->related_cpus contains the list of all valid sibling CPUs of policy->cpu. We can check this to see if the current CPU is already managed. From now on, platforms don't really need to set related_cpus from their init() routines, as the same work is done by core too. If a platform driver needs to set the related_cpus mask with some additional CPUs, other than CPUs present in policy->cpus, they are free to do it, though, as we don't override anything. [rjw: Changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Revert "cpufreq: Don't use cpu removed during ↵Viresh Kumar2013-02-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | cpufreq_driver_unregister" This reverts commit 956f339 "cpufreq: Don't use cpu removed during cpufreq_driver_unregister". With the addition of the following commit, this change/variable is not required any more: commit b9ba2725343ae57add3f324dfa5074167f48de96 Author: Viresh Kumar <viresh.kumar@linaro.org> Date: Mon Jan 14 13:23:03 2013 +0000 cpufreq: Simplify __cpufreq_remove_dev() [rjw: Subject and changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Add a get_current_driver helperBorislav Petkov2013-02-01
| | | | | | | | | | | | | | Add a helper function to return cpufreq_driver->name. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: handle cpufreq being disabled for all exported function.Dirk Brandewie2013-02-01
| | | | | | | | | | | | | | | | | | | | | | | | | | When disable_cpufreq() is called some exported functions are still being used that do not have a check for cpufreq being disabled. Add a disabled check into cpufreq_cpu_get() to return NULL if cpufreq is disabled this covers most of the exported functions. For the exported functions that do not call cpufreq_cpu_get() add an explicit check. Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Simplify __cpufreq_remove_dev()Viresh Kumar2013-02-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __cpufreq_remove_dev() is called on multiple occasions: cpufreq_driver unregister and cpu removals. Current implementation of this routine is overly complex without much need. If the cpu to be removed is the policy->cpu, we remove the policy first and add all other cpus again from policy->cpus and then finally call __cpufreq_remove_dev() again to remove the cpu to be deleted. Haahhhh.. There exist a simple solution to removal of a cpu: - Simply use the old policy structure - update its fields like: policy->cpu, etc. - notify any users of cpufreq, which depend on changing policy->cpu Hence this patch, which tries to implement the above theory. It is tested well by myself on ARM big.LITTLE TC2 SoC, which has 5 cores (2 A15 and 3 A7). Both A15's share same struct policy and all A7's share same policy structure. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Don't use cpu removed during cpufreq_driver_unregisterViresh Kumar2013-02-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is how the core works: cpufreq_driver_unregister() - subsys_interface_unregister() - for_each_cpu() call cpufreq_remove_dev(), i.e. 0,1,2,3,4 when we unregister. cpufreq_remove_dev(): - Remove policy node - Call cpufreq_add_dev() for next cpu, sharing mask with removed cpu. i.e. When cpu 0 is removed, we call it for cpu 1. And when called for cpu 2, we call it for cpu 3. - cpufreq_add_dev() would call cpufreq_driver->init() - init would return mask as AND of 2, 3 and 4 for cluster A7. - cpufreq core would do online_cpu && policy->cpus Here is the BUG(). Because cpu hasn't died but we have just unregistered the cpufreq driver, online cpu would still have cpu 2 in it. And so thing go bad again. Solution: Keep cpumask of cpus that are registered with cpufreq core and clear cpus when we get a call from subsys_interface_unregister() via cpufreq_remove_dev(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Notify governors when cpus are hot-[un]pluggedViresh Kumar2013-02-01
| | | | | | | | | | | | | | | | | | | | | | | | Because cpufreq core and governors worry only about the online cpus, if a cpu is hot [un]plugged, we must notify governors about it, otherwise be ready to expect something unexpected. We already have notifiers in the form of CPUFREQ_GOV_START/CPUFREQ_GOV_STOP, we just need to call them now. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * cpufreq: Manage only online cpusViresh Kumar2013-02-01
| | | | | | | | | | | | | | | | | | | | | | | | | | cpufreq core doesn't manage offline cpus and if driver->init() has returned mask including offline cpus, it may result in unwanted behavior by cpufreq core or governors. We need to get only online cpus in this mask. There are two places to fix this mask, cpufreq core and cpufreq driver. It makes sense to do this at common place and hence is done in core. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | PM / tracing: remove deprecated power trace APIPaul Gortmaker2013-01-25
|/ | | | | | | | | | | | | | | | | | | | The text in Documentation said it would be removed in 2.6.41; the text in the Kconfig said removal in the 3.1 release. Either way you look at it, we are well past both, so push it off a cliff. Note that the POWER_CSTATE and the POWER_PSTATE are part of the legacy tracing API. Remove all tracepoints which use these flags. As can be seen from context, most already have a trace entry via trace_cpu_idle anyways. Also, the cpufreq/cpufreq.c PSTATE one is actually unpaired, as compared to the CSTATE ones which all have a clear start/stop. As part of this, the trace_power_frequency also becomes orphaned, so it too is deleted. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Remove unnecessary initialization of a local variableJingoo Han2012-11-14
| | | | | | | | | Remove an unnecessary initializer for the 'ret' variable in __cpufreq_set_policy(). [rjw: Modified the subject and changelog slightly.] Signed-off-by: Jingoo Han <jg1.han@samsung.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Make sure target freq is within limitsViresh Kumar2012-11-14
| | | | | | | | | | | __cpufreq_driver_target() must not pass target frequency beyond the limits of current policy. Today most of cpufreq platform drivers are doing this check in their target routines. Why not move it to __cpufreq_driver_target()? Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Avoid calling cpufreq driver's target() routine if target_freq == ↵Viresh Kumar2012-11-14
| | | | | | | | | | policy->cur Avoid calling cpufreq driver's target() routine if new frequency is same as policies current frequency. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* cpufreq: Fix sparse warning by making local function staticViresh Kumar2012-11-14
| | | | | | | cpufreq_disabled() is a local function, so should be marked static. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>