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2013-08-14Merge back earlier 'pm-cpufreq' materialRafael J. Wysocki
2013-08-13cpufreq: cpufreq-cpu0: Use devm_regulator_get_optional()Mark Brown
Since the cpufreq-cpu0 driver is capable of coping without a software controllable regulator and would be confused by a dummy one it should use devm_regulator_get_optional() to ensure no dummy is provided. Signed-off-by: Mark Brown <broonie@linaro.org>
2013-08-12cpufreq: fix EXYNOS drivers selectionBartlomiej Zolnierkiewicz
* remove superfluous pr_debug() call from exynos_cpufreq_init() (init errors are always logged anyway) * add dummy per-SoC type init functions to exynos-cpufreq.h * make per-SoC type cpufreq config options selectable * make CONFIG_ARM_EXYNOS_CPUFREQ config option invisible to user and automatically enable it when needed This patch fixes following issues: * EXYNOS per-SoC type cpufreq support (i.e. exynos4210-cpufreq.c) being always built if given SoC support was enabled (i.e. CPU_EXYNOS4210), even if common EXYNOS cpufreq support was disabled * inability to select cpufreq for each SoC type separately (it could be only enabled/disabled for all SoCs for which support was enabled) * EXYNOS5440 cpufreq support was always enabled when EXYNOS5440 support was enabled and couldn't be disabled Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Reviewed-by: Tomasz Figa <t.figa@samsung.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-08-12cpufreq: exynos5440: Fix to skip when new frequency same as currentAmit Daniel Kachhap
This patch fixes the issue of un-necessary setting the clock controller when the new target frequency is same as the current one. This case usually occurs with governors like ondemand which passes the target frequency as the percentage of average frequency. This check is present in most of the cpufreq drivers. Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Amit Daniel Kachhap <amit.daniel@samsung.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-08-10cpufreq: improve error checking on return values of __cpufreq_governor()Viresh Kumar
The __cpufreq_governor() function can fail in rare cases especially if there are bugs in cpufreq drivers. Thus we must stop processing as soon as this routine fails, otherwise it may result in undefined behavior. This patch adds error checking code whenever this routine is called from any place. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-10cpufreq: Drop the owner field from struct cpufreq_driverViresh Kumar
We don't need to set .owner = THIS_MODULE any more in cpufreq drivers as this field isn't used any more by the cpufreq core. This patch removes it and updates all dependent drivers accordingly. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-10cpufreq: Use rwsem for protecting critical sectionsViresh Kumar
Critical sections of the cpufreq core are protected with the help of the driver module owner's refcount, which isn't the correct approach, because it causes rmmod to return an error when some routine has updated that refcount. Let's use rwsem for this purpose instead. Only cpufreq_unregister_driver() will use write sem and everybody else will use read sem. [rjw: Subject & changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-10cpufreq: Fix broken usage of governor->owner's refcountViresh Kumar
The cpufreq governor owner refcount usage is broken. We should only increment that refcount when a CPUFREQ_GOV_POLICY_INIT event has come and it should only be decremented if CPUFREQ_GOV_POLICY_EXIT has come. Currently, there can be situations where the governor is in use, but we have allowed it to be unloaded which may result in undefined behavior. Let's fix it. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-10cpufreq: Use cpufreq_policy_list for iterating over policiesViresh Kumar
To iterate over all policies we currently iterate over all CPUs and then get the policy for each of them. Let's use the newly created cpufreq_policy_list for this purpose. [rjw: Changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-10cpufreq: Store cpufreq policies in a listLukasz Majewski
Policies available in the cpufreq framework are now linked together. They are accessible via cpufreq_policy_list defined in the cpufreq core. [rjw: Fix from Yinghai Lu folded in] Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07cpufreq: Use sizeof(*ptr) convetion for computing sizesViresh Kumar
Chapter 14 of Documentation/CodingStyle says: The preferred form for passing a size of a struct is the following: p = kmalloc(sizeof(*p), ...); The alternative form where struct name is spelled out hurts readability and introduces an opportunity for a bug when the pointer variable type is changed but the corresponding sizeof that is passed to a memory allocator is not. This wasn't followed consistently in drivers/cpufreq, let's make it more consistent by always following this rule. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07cpufreq: Give consistent names to cpufreq_policy objectsViresh Kumar
They are called policy, cur_policy, new_policy, data, etc. Just call them policy wherever possible. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07cpufreq: Clean up header files included in the coreViresh Kumar
This patch addresses the following issues in the header files in the cpufreq core: - Include headers in ascending order, so that we don't add same many times by mistake. - <asm/> must be included after <linux/>, so that they override whatever they need to. - Remove unnecessary includes. - Don't include files already included by cpufreq.h or cpufreq_governor.h. [rjw: Changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07Merge branch 'pm-cpufreq-ondemand' into pm-cpufreqRafael J. Wysocki
* pm-cpufreq: cpufreq: Remove unused function __cpufreq_driver_getavg() cpufreq: Remove unused APERF/MPERF support cpufreq: ondemand: Change the calculation of target frequency
2013-08-07cpufreq: Pass policy to cpufreq_add_policy_cpu()Viresh Kumar
The caller of cpufreq_add_policy_cpu() already has a pointer to the policy structure and there is no need to look it up again in cpufreq_add_policy_cpu(). Let's pass it directly. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07cpufreq: Avoid double kobject_put() for the same kobject in error code pathRafael J. Wysocki
The only case triggering a jump to the err_out_unregister label in __cpufreq_add_dev() is when cpufreq_add_dev_interface() fails. However, if cpufreq_add_dev_interface() fails, it calls kobject_put() for the policy kobject in its error code path and since that causes the kobject's refcount to become 0, the additional kobject_put() for the same kobject under err_out_unregister and the wait_for_completion() following it are pointless, so drop them. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-08-07cpufreq: Do not hold driver module references for additional policy CPUsRafael J. Wysocki
The cpufreq core is a little inconsistent in the way it uses the driver module refcount. Namely, if __cpufreq_add_dev() is called for a CPU that doesn't share the policy object with any other CPUs, the driver module refcount it grabs to start with will be dropped by it before returning and will be equal to whatever it had been before that function was invoked. However, if the given CPU does share the policy object with other CPUs, either cpufreq_add_policy_cpu() is called to link the new CPU to the existing policy, or cpufreq_add_dev_symlink() is used to link the other CPUs sharing the policy with it to the just created policy object. In that case, because both cpufreq_add_policy_cpu() and cpufreq_add_dev_symlink() call cpufreq_cpu_get() for the given policy (the latter possibly many times) without the balancing cpufreq_cpu_put() (unless there is an error), the driver module refcount will be left by __cpufreq_add_dev() with a nonzero value (different from the initial one). To remove that inconsistency make cpufreq_add_policy_cpu() execute cpufreq_cpu_put() for the given policy before returning, which decrements the driver module refcount so that it will be equal to its initial value after __cpufreq_add_dev() returns. Also remove the cpufreq_cpu_get() call from cpufreq_add_dev_symlink(), since both the policy refcount and the driver module refcount are nonzero when it is called and they don't need to be bumped up by it. Accordingly, drop the cpufreq_cpu_put() from __cpufreq_remove_dev(), since it is only necessary to balance the cpufreq_cpu_get() called by cpufreq_add_policy_cpu() or cpufreq_add_dev_symlink(). Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-08-07cpufreq: Don't pass CPU to cpufreq_add_dev_{symlink|interface}()Viresh Kumar
Pointer to struct cpufreq_policy is already passed to these routines and we don't need to send policy->cpu to them as well. So, get rid of this extra argument and use policy->cpu everywhere. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07cpufreq: Remove extra variables from cpufreq_add_dev_symlink()Viresh Kumar
We call cpufreq_cpu_get() in cpufreq_add_dev_symlink() to increase usage refcount of policy, but not to get a policy for the given CPU. So, we don't really need to capture the return value of this routine. We can simply use policy passed as an argument to cpufreq_add_dev_symlink(). Moreover debug print is rewritten to make it more clear. [rjw: Changelog] Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07cpufreq: Perform light-weight init/teardown during suspend/resumeSrivatsa S. Bhat
Now that we have the infrastructure to perform a light-weight init/tear-down, use that in the cpufreq CPU hotplug notifier when invoked from the suspend/resume path. This also ensures that the file permissions of the cpufreq sysfs files are preserved across suspend/resume, something which commit a66b2e (cpufreq: Preserve sysfs files across suspend/resume) originally intended to do, but had to be reverted due to other problems. 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>
2013-08-07cpufreq: Preserve policy structure across suspend/resumeSrivatsa S. Bhat
To perform light-weight cpu-init and teardown in the cpufreq subsystem during suspend/resume, we need to separate out the 2 main functionalities of the cpufreq CPU hotplug callbacks, as outlined below: 1. Init/tear-down of core cpufreq and CPU-specific components, which are critical to the correct functioning of the cpufreq subsystem. 2. Init/tear-down of cpufreq sysfs files during suspend/resume. The first part requires accurate updates to the policy structure such as its ->cpus and ->related_cpus masks, whereas the second part requires that the policy->kobj structure is not released or re-initialized during suspend/resume. To handle both these requirements, we need to allow updates to the policy structure throughout suspend/resume, but prevent the structure from getting freed up. Also, we must have a mechanism by which the cpu-up callbacks can restore the policy structure, without allocating things afresh. (That also helps avoid memory leaks). To achieve this, we use 2 schemes: a. Use a fallback per-cpu storage area for preserving the policy structures during suspend, so that they can be restored during resume appropriately. b. Use the 'frozen' flag to determine when to free or allocate the policy structure vs when to restore the policy from the saved fallback storage. Thus we can successfully preserve the structure across suspend/resume. Effectively, this helps us complete the separation of the 'light-weight' and the 'full' init/tear-down sequences in the cpufreq subsystem, so that this can be made use of in the suspend/resume scenario. 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>
2013-08-07cpufreq: Introduce a flag ('frozen') to separate full vs temporary init/teardownSrivatsa S. Bhat
During suspend/resume we would like to do a light-weight init/teardown of CPUs in the cpufreq subsystem and preserve certain things such as sysfs files etc across suspend/resume transitions. Add a flag called 'frozen' to help distinguish the full init/teardown sequence from the light-weight one. 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>
2013-08-07cpufreq: Extract the handover of policy cpu to a helper functionSrivatsa S. Bhat
During cpu offline, when the policy->cpu is going down, some other CPU present in the policy->cpus mask is nominated as the new policy->cpu. Extract this functionality from __cpufreq_remove_dev() and implement it in a helper function. This helps in upcoming code reorganization. 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>
2013-08-07cpufreq: Extract non-interface related stuff from cpufreq_add_dev_interfaceSrivatsa S. Bhat
cpufreq_add_dev_interface() includes the work of exposing the interface to the device, as well as a lot of unrelated stuff. Move the latter to cpufreq_add_dev(), where it is more appropriate. 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>
2013-08-07cpufreq: Add helper to perform alloc/free of policy structureSrivatsa S. Bhat
Separate out the allocation of the cpufreq policy structure (along with its error handling) to a helper function. This makes the code easier to read and also helps with some upcoming code reorganization. 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>
2013-08-07cpufreq: Fix misplaced call to cpufreq_update_policy()Srivatsa S. Bhat
The call to cpufreq_update_policy() is placed in the CPU hotplug callback of cpufreq_stats, which has a higher priority than the CPU hotplug callback of cpufreq-core. As a result, during CPU_ONLINE/CPU_ONLINE_FROZEN, we end up calling cpufreq_update_policy() *before* calling cpufreq_add_dev() ! And for uninitialized CPUs, it just returns silently, not doing anything. To add to that, cpufreq_stats is not even the right place to call cpufreq_update_policy() to begin with. The cpufreq core ought to handle this in its own callback, from an elegance/relevance perspective. So move the invocation of cpufreq_update_policy() to cpufreq_cpu_callback, and place it *after* cpufreq_add_dev(). 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>
2013-08-07cpufreq: rename ignore_nice as ignore_nice_loadViresh Kumar
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> Cc: 3.10+ <stable@vger.kernel.org> # 3.10+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-08-07cpufreq: loongson2: fix regression related to clock managementAaro Koskinen
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> Cc: 3.9+ <stable@vger.kernel.org> # 3.9+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-30cpufreq: Fix cpufreq driver module refcount balance after suspend/resumeRafael J. Wysocki
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>
2013-07-26cpufreq: Remove unused function __cpufreq_driver_getavg()Stratos Karafotis
The target frequency calculation method in the ondemand governor has changed and it is now independent of the measured average frequency. Consequently, the __cpufreq_driver_getavg() function and getavg member of struct cpufreq_driver are not used any more, so drop them. [rjw: Changelog] Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-26cpufreq: Remove unused APERF/MPERF supportStratos Karafotis
The target frequency calculation method in the ondemand governor has changed and it is now independent of the measured average frequency. Consequently, the APERF/MPERF support in cpufreq is not used any more, so drop it. [rjw: Changelog] Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-26cpufreq: ondemand: Change the calculation of target frequencyStratos Karafotis
The ondemand governor calculates load in terms of frequency and increases it only if load_freq is greater than up_threshold multiplied by the current or average frequency. This appears to produce oscillations of frequency between min and max because, for example, a relatively small load can easily saturate minimum frequency and lead the CPU to the max. Then, it will decrease back to the min due to small load_freq. Change the calculation method of load and target frequency on the basis of the following two observations: - Load computation should not depend on the current or average measured frequency. For example, absolute load of 80% at 100MHz is not necessarily equivalent to 8% at 1000MHz in the next sampling interval. - It should be possible to increase the target frequency to any value present in the frequency table proportional to the absolute load, rather than to the max only, so that: Target frequency = C * load where we take C = policy->cpuinfo.max_freq / 100. Tested on Intel i7-3770 CPU @ 3.40GHz and on Quad core 1500MHz Krait. Phoronix benchmark of Linux Kernel Compilation 3.1 test shows an increase ~1.5% in performance. cpufreq_stats (time_in_state) shows that middle frequencies are used more, with this patch. Highest and lowest frequencies were used less by ~9%. [rjw: We have run multiple other tests on kernels with this change applied and in the vast majority of cases it turns out that the resulting performance improvement also leads to reduced consumption of energy. The change is additionally justified by the overall simplification of the code in question.] Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-23cpufreq / intel_pstate: Change to scale off of max P-stateDirk Brandewie
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> Cc: 3.9+ <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-19Merge tag 'pm+acpi-3.11-rc2' of ↵Linus Torvalds
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
2013-07-16cpufreq: Revert commit 2f7021a8 to fix CPU hotplug regressionSrivatsa S. Bhat
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> Cc: 3.10+ <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-14cpufreq: delete __cpuinit usage from all cpufreq filesPaul Gortmaker
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>
2013-07-15cpufreq: s3c24xx: rename CONFIG_CPU_FREQ_S3C24XX_DEBUGFSPaul Bolle
The Kconfig symbol CPU_FREQ_S3C24XX_DEBUGFS was renamed to ARM_S3C24XX_CPUFREQ_DEBUGFS in commit f023f8dd59 ("cpufreq: s3c24xx: move cpufreq driver to drivers/cpufreq"). But that commit missed one instance of its macro CONFIG_CPU_FREQ_S3C24XX_DEBUGFS. Rename it too. Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-07-15cpufreq: Revert commit a66b2e to fix suspend/resume regressionSrivatsa S. Bhat
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>
2013-07-11Merge tag 'pm+acpi-3.11-rc1-more' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management and ACPI updates from Rafael Wysocki: - Fix for a recent cpufreq regression that caused WARN() to trigger overzealously in a couple of places and spam the kernel log with useless garbage as a result. From Viresh Kumar. - ACPI dock fix removing a discrepancy between the definition of acpi_dock_init(), which says that the function returns int, and its header in the header file, which says that it is a void function. The function is now defined as void too. - ACPI PM fix for failures to update device power states as needed, for example, during resume from system suspend, because the old state was deeper than the new one, but the new one is not D0. - Fix for two debug messages in the ACPI power resources code that don't have a newline at the end and make the kernel log difficult to read. From Mika Westerberg. - Two ACPI cleanups from Naresh Bhat and Haicheng Li. - cpupower updates from Thomas Renninger, including Intel Haswell support improvements and a new idle-set subcommand among other things. * tag 'pm+acpi-3.11-rc1-more' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / power: add missing newline to debug messages cpupower: Add Haswell family 0x45 specific idle monitor to show PC8,9,10 states cpupower: Haswell also supports the C-states introduced with SandyBridge cpupower: Introduce idle-set subcommand and C-state enabling/disabling cpupower: Implement disabling of cstate interface cpupower: Make idlestate usage unsigned ACPI / fan: Initialize acpi_state variable ACPI / scan: remove unused LIST_HEAD(acpi_device_list) ACPI / dock: Actually define acpi_dock_init() as void ACPI / PM: Fix corner case in acpi_bus_update_power() cpufreq: Fix serialization of frequency transitions
2013-07-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "The usual stuff from trivial tree" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (34 commits) treewide: relase -> release Documentation/cgroups/memory.txt: fix stat file documentation sysctl/net.txt: delete reference to obsolete 2.4.x kernel spinlock_api_smp.h: fix preprocessor comments treewide: Fix typo in printk doc: device tree: clarify stuff in usage-model.txt. open firmware: "/aliasas" -> "/aliases" md: bcache: Fixed a typo with the word 'arithmetic' irq/generic-chip: fix a few kernel-doc entries frv: Convert use of typedef ctl_table to struct ctl_table sgi: xpc: Convert use of typedef ctl_table to struct ctl_table doc: clk: Fix incorrect wording Documentation/arm/IXP4xx fix a typo Documentation/networking/ieee802154 fix a typo Documentation/DocBook/media/v4l fix a typo Documentation/video4linux/si476x.txt fix a typo Documentation/virtual/kvm/api.txt fix a typo Documentation/early-userspace/README fix a typo Documentation/video4linux/soc-camera.txt fix a typo lguest: fix CONFIG_PAE -> CONFIG_x86_PAE in comment ...
2013-07-04cpufreq: Fix serialization of frequency transitionsViresh Kumar
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>
2013-07-03Merge tag 'pm+acpi-3.11-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI updates from Rafael Wysocki: "This time the total number of ACPI commits is slightly greater than the number of cpufreq commits, but Viresh Kumar (who works on cpufreq) remains the most active patch submitter. To me, the most significant change is the addition of offline/online device operations to the driver core (with the Greg's blessing) and the related modifications of the ACPI core hotplug code. Next are the freezer updates from Colin Cross that should make the freezing of tasks a bit less heavy weight. We also have a couple of regression fixes, a number of fixes for issues that have not been identified as regressions, two new drivers and a bunch of cleanups all over. Highlights: - Hotplug changes to support graceful hot-removal failures. It sometimes is necessary to fail device hot-removal operations gracefully if they cannot be carried out completely. For example, if memory from a memory module being hot-removed has been allocated for the kernel's own use and cannot be moved elsewhere, it's desirable to fail the hot-removal operation in a graceful way rather than to crash the kernel, but currenty a success or a kernel crash are the only possible outcomes of an attempted memory hot-removal. Needless to say, that is not a very attractive alternative and it had to be addressed. However, in order to make it work for memory, I first had to make it work for CPUs and for this purpose I needed to modify the ACPI processor driver. It's been split into two parts, a resident one handling the low-level initialization/cleanup and a modular one playing the actual driver's role (but it binds to the CPU system device objects rather than to the ACPI device objects representing processors). That's been sort of like a live brain surgery on a patient who's riding a bike. So this is a little scary, but since we found and fixed a couple of regressions it caused to happen during the early linux-next testing (a month ago), nobody has complained. As a bonus we remove some duplicated ACPI hotplug code, because the ACPI-based CPU hotplug is now going to use the common ACPI hotplug code. - Lighter weight freezing of tasks. These changes from Colin Cross and Mandeep Singh Baines are targeted at making the freezing of tasks a bit less heavy weight operation. They reduce the number of tasks woken up every time during the freezing, by using the observation that the freezer simply doesn't need to wake up some of them and wait for them all to call refrigerator(). The time needed for the freezer to decide to report a failure is reduced too. Also reintroduced is the check causing a lockdep warining to trigger when try_to_freeze() is called with locks held (which is generally unsafe and shouldn't happen). - cpufreq updates First off, a commit from Srivatsa S Bhat fixes a resume regression introduced during the 3.10 cycle causing some cpufreq sysfs attributes to return wrong values to user space after resume. The fix is kind of fresh, but also it's pretty obvious once Srivatsa has identified the root cause. Second, we have a new freqdomain_cpus sysfs attribute for the acpi-cpufreq driver to provide information previously available via related_cpus. From Lan Tianyu. Finally, we fix a number of issues, mostly related to the CPUFREQ_POSTCHANGE notifier and cpufreq Kconfig options and clean up some code. The majority of changes from Viresh Kumar with bits from Jacob Shin, Heiko Stübner, Xiaoguang Chen, Ezequiel Garcia, Arnd Bergmann, and Tang Yuantian. - ACPICA update A usual bunch of updates from the ACPICA upstream. During the 3.4 cycle we introduced support for ACPI 5 extended sleep registers, but they are only supposed to be used if the HW-reduced mode bit is set in the FADT flags and the code attempted to use them without checking that bit. That caused suspend/resume regressions to happen on some systems. Fix from Lv Zheng causes those registers to be used only if the HW-reduced mode bit is set. Apart from this some other ACPICA bugs are fixed and code cleanups are made by Bob Moore, Tomasz Nowicki, Lv Zheng, Chao Guan, and Zhang Rui. - cpuidle updates New driver for Xilinx Zynq processors is added by Michal Simek. Multidriver support simplification, addition of some missing kerneldoc comments and Kconfig-related fixes come from Daniel Lezcano. - ACPI power management updates Changes to make suspend/resume work correctly in Xen guests from Konrad Rzeszutek Wilk, sparse warning fix from Fengguang Wu and cleanups and fixes of the ACPI device power state selection routine. - ACPI documentation updates Some previously missing pieces of ACPI documentation are added by Lv Zheng and Aaron Lu (hopefully, that will help people to uderstand how the ACPI subsystem works) and one outdated doc is updated by Hanjun Guo. - Assorted ACPI updates We finally nailed down the IA-64 issue that was the reason for reverting commit 9f29ab11ddbf ("ACPI / scan: do not match drivers against objects having scan handlers"), so we can fix it and move the ACPI scan handler check added to the ACPI video driver back to the core. A mechanism for adding CMOS RTC address space handlers is introduced by Lan Tianyu to allow some EC-related breakage to be fixed on some systems. A spec-compliant implementation of acpi_os_get_timer() is added by Mika Westerberg. The evaluation of _STA is added to do_acpi_find_child() to avoid situations in which a pointer to a disabled device object is returned instead of an enabled one with the same _ADR value. From Jeff Wu. Intel BayTrail PCH (Platform Controller Hub) support is added to the ACPI driver for Intel Low-Power Subsystems (LPSS) and that driver is modified to work around a couple of known BIOS issues. Changes from Mika Westerberg and Heikki Krogerus. The EC driver is fixed by Vasiliy Kulikov to use get_user() and put_user() instead of dereferencing user space pointers blind