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path: root/drivers/base/power/runtime.c
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2017-03-02sched/headers: Prepare to move the memalloc_noio_*() APIs to <linux/sched/mm.h>Ingo Molnar
Update the .c files that depend on these APIs. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-04PM / runtime: Avoid false-positive warnings from might_sleep_if()Rafael J. Wysocki
The might_sleep_if() assertions in __pm_runtime_idle(), __pm_runtime_suspend() and __pm_runtime_resume() may generate false-positive warnings in some situations. For example, that happens if a nested pm_runtime_get_sync()/pm_runtime_put() pair is executed with disabled interrupts within an outer pm_runtime_get_sync()/pm_runtime_put() section for the same device. [Generally, pm_runtime_get_sync() may sleep, so it should not be called with disabled interrupts, but in this particular case the previous pm_runtime_get_sync() guarantees that the device will not be suspended, so the inner pm_runtime_get_sync() will return immediately after incrementing the device's usage counter.] That started to happen in the i915 driver in 4.10-rc, leading to the following splat: BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:1032 in_atomic(): 1, irqs_disabled(): 0, pid: 1500, name: Xorg 1 lock held by Xorg/1500: #0: (&dev->struct_mutex){+.+.+.}, at: [<ffffffffa0680c13>] i915_mutex_lock_interruptible+0x43/0x140 [i915] CPU: 0 PID: 1500 Comm: Xorg Not tainted Call Trace: dump_stack+0x85/0xc2 ___might_sleep+0x196/0x260 __might_sleep+0x53/0xb0 __pm_runtime_resume+0x7a/0x90 intel_runtime_pm_get+0x25/0x90 [i915] aliasing_gtt_bind_vma+0xaa/0xf0 [i915] i915_vma_bind+0xaf/0x1e0 [i915] i915_gem_execbuffer_relocate_entry+0x513/0x6f0 [i915] i915_gem_execbuffer_relocate_vma.isra.34+0x188/0x250 [i915] ? trace_hardirqs_on+0xd/0x10 ? i915_gem_execbuffer_reserve_vma.isra.31+0x152/0x1f0 [i915] ? i915_gem_execbuffer_reserve.isra.32+0x372/0x3a0 [i915] i915_gem_do_execbuffer.isra.38+0xa70/0x1a40 [i915] ? __might_fault+0x4e/0xb0 i915_gem_execbuffer2+0xc5/0x260 [i915] ? __might_fault+0x4e/0xb0 drm_ioctl+0x206/0x450 [drm] ? i915_gem_execbuffer+0x340/0x340 [i915] ? __fget+0x5/0x200 do_vfs_ioctl+0x91/0x6f0 ? __fget+0x111/0x200 ? __fget+0x5/0x200 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x23/0xc6 even though the code triggering it is correct. Unfortunately, the might_sleep_if() assertions in question are too coarse-grained to cover such cases correctly, so make them a bit less sensitive in order to avoid the false-positives. Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-12-13Merge tag 'driver-core-4.10-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here's the new driver core patches for 4.10-rc1. Big thing here is the nice addition of "functional dependencies" to the driver core. The idea has been talked about for a very long time, great job to Rafael for stepping up and implementing it. It's been tested for longer than the 4.9-rc1 date, we held off on merging it earlier in order to feel more comfortable about it. Other than that, it's just a handful of small other patches, some good cleanups to the mess that is the firmware class code, and we have a test driver for the deferred probe logic. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (30 commits) firmware: Correct handling of fw_state_wait() return value driver core: Silence device links sphinx warning firmware: remove warning at documentation generation time drivers: base: dma-mapping: Fix typo in dmam_alloc_non_coherent comments driver core: test_async: fix up typo found by 0-day firmware: move fw_state_is_done() into UHM section firmware: do not use fw_lock for fw_state protection firmware: drop bit ops in favor of simple state machine firmware: refactor loading status firmware: fix usermode helper fallback loading driver core: firmware_class: convert to use class_groups driver core: devcoredump: convert to use class_groups driver core: class: add class_groups support kernfs: Declare two local data structures static driver-core: fix platform_no_drv_owner.cocci warnings drivers/base/memory.c: Remove unused 'first_page' variable driver core: add CLASS_ATTR_WO() drivers: base: cacheinfo: support DT overrides for cache properties drivers: base: cacheinfo: add pr_fmt logging drivers: base: cacheinfo: fix boot error message when acpi is enabled ...
2016-12-06PM / wakeirq: Fix dedicated wakeirq for drivers not using autosuspendTony Lindgren
I noticed some wakeirq flakeyness with consumer drivers not using autosuspend. For drivers not using autosuspend, the wakeirq may never get unmasked in rpm_suspend() because of irq desc->depth. We are configuring dedicated wakeirqs to start with IRQ_NOAUTOEN as we naturally don't want them running until rpm_suspend() is called. However, when a consumer driver initially calls pm_runtime_get(), we now wrongly start with disable_irq_nosync() call on the dedicated wakeirq that is disabled to start with. This causes desc->depth to toggle between 1 and 2 instead of the usual 0 and 1. This can prevent enable_irq() from unmasking the wakeirq as that only happens at desc->depth 1. This does not necessarily show up with drivers using autosuspend as there is time for disable_irq_nosync() before rpm_suspend() gets called after the autosuspend timeout. Let's fix the issue by adding wirq->status that lazily gets set on the first rpm_suspend(). We also need PM runtime core private functions for dev_pm_enable_wake_irq_check() and dev_pm_disable_wake_irq_check() so we can enable the dedicated wakeirq on the first rpm_suspend(). While at it, let's also fix the comments for dev_pm_enable_wake_irq() and dev_pm_disable_wake_irq(). Those can still be used by the consumer drivers as needed because the IRQ core manages the interrupt usecount for us. Fixes: 4990d4fe327b (PM / Wakeirq: Add automated device wake IRQ handling) Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-19PM / Runtime: Defer resuming of the device in pm_runtime_force_resume()Ulf Hansson
When the pm_runtime_force_suspend|resume() helpers were invented, we still had CONFIG_PM_RUNTIME and CONFIG_PM_SLEEP as separate Kconfig options. To make sure these helpers worked for all combinations and without introducing too much of complexity, the device was always resumed in pm_runtime_force_resume(). More precisely, when CONFIG_PM_SLEEP was set and CONFIG_PM_RUNTIME was unset, we needed to resume the device as the subsystem/driver couldn't rely on using runtime PM to do it. As the CONFIG_PM_RUNTIME option was merged into CONFIG_PM a while ago, it removed this combination, of using CONFIG_PM_SLEEP without the earlier CONFIG_PM_RUNTIME. For this reason we can now rely on the subsystem/driver to use runtime PM to resume the device, instead of forcing that to be done in all cases. In other words, let's defer the runtime resume to a later point when it's actually needed. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-11-09PM / Runtime: Don't allow to suspend a device with an active childUlf Hansson
When resuming a device in __pm_runtime_set_status(), the prerequisite is that its parent must already be active, else an error code is returned and the device's status remains suspended. When suspending a device there is no similar constraints being validated. Let's change this to make the behaviour consistent, by not allowing to suspend a device with an active child, unless it has been explicitly set to ignore its children. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-31PM / runtime: Optimize the use of device linksRafael J. Wysocki
If the device has no links to suppliers that should be used for runtime PM (links with DEVICE_LINK_PM_RUNTIME set), there is no reason to walk the list of suppliers for that device during runtime suspend and resume. Add a simple mechanism to detect that case and possibly avoid the extra unnecessary overhead. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-31PM / runtime: Use device linksRafael J. Wysocki
Modify the runtime PM framework to use device links to ensure that supplier devices will not be suspended if any of their consumer devices are active. The idea is to reference count suppliers on the consumer's resume and drop references to them on its suspend. The information on whether or not the supplier has been reference counted by the consumer's (runtime) resume is stored in a new field (rpm_active) in the link object for each link. It may be necessary to clean up those references when the supplier is unbinding and that's why the links whose status is DEVICE_LINK_SUPPLIER_UNBIND are skipped by the runtime suspend and resume code. The above means that if the consumer device is probed in the runtime-active state, the supplier has to be resumed and reference counted by device_link_add() so the code works as expected on its (runtime) suspend. There is a new flag, DEVICE_LINK_RPM_ACTIVE, to tell device_link_add() about that (in which case the caller is responsible for making sure that the consumer really will be runtime-active when runtime PM is enabled for it). The other new link flag, DEVICE_LINK_PM_RUNTIME, tells the core whether or not the link should be used for runtime PM at all. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-21PM / Runtime: Clarify comment in rpm_resume() when resuming the parentUlf Hansson
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-10-21PM / Runtime: Remove the exported function pm_children_suspended()Ulf Hansson
The exported function pm_children_suspended() has only one caller, which is the runtime PM internal function, rpm_check_suspend_allowed(). Let's clean-up this code, by removing pm_children_suspended() altogether and instead do the one-liner check directly in rpm_check_suspend_allowed(). Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-09-16PM / runtime: Use _rcuidle for runtime suspend tracepointsPaul E. McKenney
Further testing with false negatives suppressed by commit 293e2421fe25 ("rcu: Remove superfluous versions of rcu_read_lock_sched_held()") identified a few more unprotected uses of RCU from the idle loop. Because RCU actively ignores idle-loop code (for energy-efficiency reasons, among other things), using RCU from the idle loop can result in too-short grace periods, in turn resulting in arbitrary misbehavior. The affected function is rpm_suspend(). The resulting lockdep-RCU splat is as follows: ------------------------------------------------------------------------ Warning from omap3 =============================== [ INFO: suspicious RCU usage. ] 4.6.0-rc5-next-20160426+ #1112 Not tainted ------------------------------- include/trace/events/rpm.h:63 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from idle CPU! rcu_scheduler_active = 1, debug_locks = 0 RCU used illegally from extended quiescent state! 1 lock held by swapper/0/0: #0: (&(&dev->power.lock)->rlock){-.-...}, at: [<c052ee24>] __pm_runtime_suspend+0x54/0x84 stack backtrace: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1112 Hardware name: Generic OMAP36xx (Flattened Device Tree) [<c0110308>] (unwind_backtrace) from [<c010c3a8>] (show_stack+0x10/0x14) [<c010c3a8>] (show_stack) from [<c047fec8>] (dump_stack+0xb0/0xe4) [<c047fec8>] (dump_stack) from [<c052d7b4>] (rpm_suspend+0x604/0x7e4) [<c052d7b4>] (rpm_suspend) from [<c052ee34>] (__pm_runtime_suspend+0x64/0x84) [<c052ee34>] (__pm_runtime_suspend) from [<c04bf3bc>] (omap2_gpio_prepare_for_idle+0x5c/0x70) [<c04bf3bc>] (omap2_gpio_prepare_for_idle) from [<c01255e8>] (omap_sram_idle+0x140/0x244) [<c01255e8>] (omap_sram_idle) from [<c0126b48>] (omap3_enter_idle_bm+0xfc/0x1ec) [<c0126b48>] (omap3_enter_idle_bm) from [<c0601db8>] (cpuidle_enter_state+0x80/0x3d4) [<c0601db8>] (cpuidle_enter_state) from [<c0183c74>] (cpu_startup_entry+0x198/0x3a0) [<c0183c74>] (cpu_startup_entry) from [<c0b00c0c>] (start_kernel+0x354/0x3c8) [<c0b00c0c>] (start_kernel) from [<8000807c>] (0x8000807c) ------------------------------------------------------------------------ Reported-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Guenter Roeck <linux@roeck-us.net> [ rjw: Subject ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31PM / runtime: Add _rcuidle suffix to allow rpm_idle() use from idlePaul E. McKenney
This commit appends a few _rcuidle suffixes to fix the following RCU-used-from-idle bug: > =============================== > [ INFO: suspicious RCU usage. ] > 4.6.0-rc5-next-20160426+ #1116 Not tainted > ------------------------------- > include/trace/events/rpm.h:95 suspicious rcu_dereference_check() usage! > > other info that might help us debug this: > > > RCU used illegally from idle CPU! > rcu_scheduler_active = 1, debug_locks = 0 > RCU used illegally from extended quiescent state! > 1 lock held by swapper/0/0: > #0: (&(&dev->power.lock)->rlock){-.-...}, at: [<c052cc2c>] __rpm_callback+0x58/0x60 > > stack backtrace: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1116 > Hardware name: Generic OMAP36xx (Flattened Device Tree) > [<c0110290>] (unwind_backtrace) from [<c010c3a8>] (show_stack+0x10/0x14) > [<c010c3a8>] (show_stack) from [<c047fd68>] (dump_stack+0xb0/0xe4) > [<c047fd68>] (dump_stack) from [<c052d5d0>] (rpm_suspend+0x580/0x768) > [<c052d5d0>] (rpm_suspend) from [<c052ec58>] (__pm_runtime_suspend+0x64/0x84) > [<c052ec58>] (__pm_runtime_suspend) from [<c04bf25c>] (omap2_gpio_prepare_for_idle+0x5c/0x70) > [<c04bf25c>] (omap2_gpio_prepare_for_idle) from [<c0125568>] (omap_sram_idle+0x140/0x244) > [<c0125568>] (omap_sram_idle) from [<c01269dc>] (omap3_enter_idle_bm+0xfc/0x1ec) > [<c01269dc>] (omap3_enter_idle_bm) from [<c0601bdc>] (cpuidle_enter_state+0x80/0x3d4) > [<c0601bdc>] (cpuidle_enter_state) from [<c0183b08>] (cpu_startup_entry+0x198/0x3a0) > [<c0183b08>] (cpu_startup_entry) from [<c0b00c0c>] (start_kernel+0x354/0x3c8) > [<c0b00c0c>] (start_kernel) from [<8000807c>] (0x8000807c) In the immortal words of Steven Rostedt, "*Whack* *Whack* *Whack*!!!" Reported-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Guenter Roeck <linux@roeck-us.net> WhACKED-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31PM / runtime: Add _rcuidle suffix to allow rpm_resume() to be called from idlePaul E. McKenney
This commit applies another _rcuidle suffix to fix an RCU use from idle. > =============================== > [ INFO: suspicious RCU usage. ] > 4.6.0-rc5-next-20160426+ #1122 Not tainted > ------------------------------- > include/trace/events/rpm.h:69 suspicious rcu_dereference_check() usage! > > other info that might help us debug this: > > > RCU used illegally from idle CPU! > rcu_scheduler_active = 1, debug_locks = 0 > RCU used illegally from extended quiescent state! > 1 lock held by swapper/0/0: > #0: (&(&dev->power.lock)->rlock){-.-...}, at: [<c052e3dc>] __pm_runtime_resume+0x3c/0x64 > > stack backtrace: > CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.6.0-rc5-next-20160426+ #1122 > Hardware name: Generic OMAP36xx (Flattened Device Tree) > [<c0110290>] (unwind_backtrace) from [<c010c3a8>] (show_stack+0x10/0x14) > [<c010c3a8>] (show_stack) from [<c047fd68>] (dump_stack+0xb0/0xe4) > [<c047fd68>] (dump_stack) from [<c052e178>] (rpm_resume+0x5cc/0x7f4) > [<c052e178>] (rpm_resume) from [<c052e3ec>] (__pm_runtime_resume+0x4c/0x64) > [<c052e3ec>] (__pm_runtime_resume) from [<c04bf2c4>] (omap2_gpio_resume_after_idle+0x54/0x68) > [<c04bf2c4>] (omap2_gpio_resume_after_idle) from [<c01269dc>] (omap3_enter_idle_bm+0xfc/0x1ec) > [<c01269dc>] (omap3_enter_idle_bm) from [<c060198c>] (cpuidle_enter_state+0x80/0x3d4) > [<c060198c>] (cpuidle_enter_state) from [<c0183b08>] (cpu_startup_entry+0x198/0x3a0) > [<c0183b08>] (cpu_startup_entry) from [<c0b00c0c>] (start_kernel+0x354/0x3c8) > [<c0b00c0c>] (start_kernel) from [<8000807c>] (0x8000807c) Reported-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-07-25Merge branches 'pm-core', 'pm-clk', 'pm-domains' and 'pm-pci'Rafael J. Wysocki
* pm-core: PM / runtime: Asynchronous "idle" in pm_runtime_allow() PM / runtime: print error when activating a child to unactive parent * pm-clk: PM / clk: Add support for adding a specific clock from device-tree PM / clk: export symbols for existing pm_clk_<...> API fcns * pm-domains: PM / Domains: Convert pm_genpd_init() to return an error code PM / Domains: Stop/start devices during system PM suspend/resume in genpd PM / Domains: Allow runtime PM during system PM phases PM / Runtime: Avoid resuming devices again in pm_runtime_force_resume() PM / Domains: Remove redundant pm_request_idle() call in genpd PM / Domains: Remove redundant wrapper functions for system PM PM / Domains: Allow genpd to power on during system PM phases * pm-pci: PCI / PM: check all fields in pci_set_platform_pm()
2016-07-02PM / runtime: Asynchronous "idle" in pm_runtime_allow()Rafael J. Wysocki
Arjan reports that it takes a relatively long time to enable runtime PM for multiple devices at system startup, because all writes to the "control" attribute in sysfs are handled synchronously and if the device is suspended as a result of the write, it will block until that operation is complete. That may be avoided by passing the RPM_ASYNC flag to rpm_idle() in pm_runtime_allow() which will make it execute the device's "idle" callback asynchronously, so writes to "control" changing it from "on" to "auto" will return without waiting. Reported-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Alan Stern <stern@rowland.harvard.edu> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Kevin Hilman <khilman@baylibre.com>
2016-06-28PM / runtime: print error when activating a child to unactive parentLinus Walleij
The code currently silently bails out with -EBUSY if you try to activate a child to an inactive parent. This typically happens when you have a runtime suspended parent and runtime resume your child, but forgot to set .ignore_children on the parent to true with pm_suspend_ignore_children(dev). Silently ignoring this error is not good as it gives rise to other strange behaviour like double-resume of devices after silently bailing out of the .runtime_resume() callback. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-16PM / Runtime: Avoid resuming devices again in pm_runtime_force_resume()Ulf Hansson
If the runtime PM status of the device isn't RPM_SUSPENDED, prevent the pm_runtime_force_resume() from invoking the ->runtime_resume() callback for the device, as it's not the expected behaviour from the subsystem/driver. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-21PM / Runtime: Fix error path in pm_runtime_force_resume()Ulf Hansson
As pm_runtime_set_active() may fail because the device's parent isn't active, we can end up executing the ->runtime_resume() callback for the device when it isn't allowed. Fix this by invoking pm_runtime_set_active() before running the callback and let's also deal with the error code. Fixes: 37f204164dfb (PM: Add pm_runtime_suspend|resume_force functions) Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Cc: 3.15+ <stable@vger.kernel.org> # 3.15+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-12-21PM / runtime: Add new helper for conditional usage count incrementationRafael J. Wysocki
Introduce a new runtime PM function, pm_runtime_get_if_in_use(), that will increment the device's runtime PM usage counter and return 1 if its status is RPM_ACTIVE and its usage counter is greater than 0 at the same time (0 will be returned otherwise). This is useful for things that should only be done if the device is active (from the runtime PM perspective) and used by somebody (as indicated by the usage counter) already and they are not worth bothering otherwise. Requested-by: Imre Deak <imre.deak@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-30PM / runtime: Re-init runtime PM states at probe error and driver unbindUlf Hansson
There are two common expectations among several subsystems/drivers that deploys runtime PM support, but which isn't met by the driver core. Expectation 1) At ->probe() the subsystem/driver expects the runtime PM status of the device to be RPM_SUSPENDED, which is the initial status being assigned at device registration. This expectation is especially common among some of those subsystems/ drivers that manages devices with an attached PM domain, as those requires the ->runtime_resume() callback at the PM domain level to be invoked during ->probe(). Moreover these subsystems/drivers entirely relies on runtime PM resources being managed at the PM domain level, thus don't implement their own set of runtime PM callbacks. These are two scenarios that suffers from this unmet expectation. i) A failed ->probe() sequence requests probe deferral: ->probe() ... pm_runtime_enable() pm_runtime_get_sync() ... err: pm_runtime_put() pm_runtime_disable() ... As there are no guarantees that such sequence turns the runtime PM status of the device into RPM_SUSPENDED, the re-trying ->probe() may start with the status in RPM_ACTIVE. In such case the runtime PM core won't invoke the ->runtime_resume() callback because of a pm_runtime_get_sync(), as it considers the device to be already runtime resumed. ii) A driver re-bind sequence: At driver unbind, the subsystem/driver's >remove() callback invokes a sequence of runtime PM APIs, to undo actions during ->probe() and to put the device into low power state. ->remove() ... pm_runtime_put() pm_runtime_disable() ... Similar as in the failing ->probe() case, this sequence don't guarantee the runtime PM status of the device to turn into RPM_SUSPENDED. Trying to re-bind the driver thus causes the same issue as when re-trying ->probe(), in the probe deferral scenario. Expectation 2) Drivers that invokes the pm_runtime_irq_safe() API during ->probe(), triggers the runtime PM core to increase the usage count for the device's parent and permanently make it runtime resumed. The usage count is only dropped at device removal, which also allows it to be runtime suspended again. A re-trying ->probe() repeats the call to pm_runtime_irq_safe() and thus once more triggers the usage count of the device's parent to be increased. This leads to not only an imbalance issue of the usage count of the device's parent, but also to keep it runtime resumed permanently even if ->probe() fails. To address these issues, let's change the policy of the driver core to meet these expectations. More precisely, at ->probe() failures and driver unbind, restore the initial states of runtime PM. Although to still allow subsystem's to control PM for devices that doesn't ->probe() successfully, don't restore the initial states unless runtime PM is disabled. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-20PM / Wakeirq: Add automated device wake IRQ handlingTony Lindgren
Turns out we can automate the handling for the device_may_wakeup() quite a bit by using the kernel wakeup source list as suggested by Rafael J. Wysocki <rjw@rjwysocki.net>. And as some hardware has separate dedicated wake-up interrupt in addition to the IO interrupt, we can automate the handling by adding a generic threaded interrupt handler that just calls the device PM runtime to wake up the device. This allows dropping code from device drivers as we currently are doing it in multiple ways, and often wrong. For most drivers, we should be able to drop the following boilerplate code from runtime_suspend and runtime_resume functions: ... device_init_wakeup(dev, true); ... if (device_may_wakeup(dev)) enable_irq_wake(irq); ... if (device_may_wakeup(dev)) disable_irq_wake(irq); ... device_init_wakeup(dev, false); ... We can replace it with just the following init and exit time code: ... device_init_wakeup(dev, true); dev_pm_set_wake_irq(dev, irq); ... dev_pm_clear_wake_irq(dev); device_init_wakeup(dev, false); ... And for hardware with dedicated wake-up interrupts: ... device_init_wakeup(dev, true); dev_pm_set_dedicated_wake_irq(dev, irq); ... dev_pm_clear_wake_irq(dev); device_init_wakeup(dev, false); ... Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-05-20PM / Runtime: Update last_busy in rpm_resumeTony Lindgren
If we don't update last_busy in rpm_resume, devices can go back to sleep immediately after resume. This happens at least in cases where the device has been powered off and does not have any interrupt pending until there's something in the FIFO. Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-12-04PM: Drop CONFIG_PM_RUNTIME from the driver coreRafael J. Wysocki
After commit b2b49ccbdd54 (PM: Kconfig: Set PM_RUNTIME if PM_SLEEP is selected) PM_RUNTIME is always set if PM is set, so quite a few depend on CONFIG_PM or even may be dropped entirely in some cases. Replace CONFIG_PM_RUNTIME with CONFIG_PM in the PM core code. Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-11-06PM / Runtime: Rework RPM get callback routinesAndrzej Hajda
PM uses three separate functions to fetch RPM callbacks. These functions uses quite complicated macro in their body. The patch replaces these routines with one small macro and one helper function. Signed-off-by: Andrzej Hajda <a.hajda@samsung.com> Acked-by: Pavel Machek <pavel@ucw.cz> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-20Merge branches 'pm-runtime' and 'pm-sleep'Rafael J. Wysocki
* pm-runtime: PM / Runtime: Update runtime_idle() documentation for return value meaning * pm-sleep: PM / sleep: Correct whitespace errors in <linux/pm.h> PM: Add missing "freeze" state PM / Hibernate: Spelling s/anonymouns/anonymous/ PM / Runtime: Add missing "it" in comment PM / suspend: Remove unnecessary !! PCI / PM: Resume runtime-suspended devices later during system suspend ACPI / PM: Resume runtime-suspended devices later during system suspend PM / sleep: Set pm_generic functions to NULL for !CONFIG_PM_SLEEP PM: fix typo in comment PM / hibernate: use name_to_dev_t to parse resume PM / wakeup: Include appropriate header file in kernel/power/wakelock.c PM / sleep: Move prototype declaration to header file kernel/power/power.h PM / sleep: Asynchronous threads for suspend_late PM / sleep: Asynchronous threads for suspend_noirq PM / sleep: Asynchronous threads for resume_early PM / sleep: Asynchronous threads for resume_noirq PM / sleep: Two flags for async suspend_noirq and suspend_late
2014-03-12PM / Runtime: Add missing "it" in commentGeert Uytterhoeven
Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-02PM: Add pm_runtime_suspend|resume_force functionsUlf Hansson
This patch provides two new runtime PM helper functions which intend to be used from system suspend/resume callbacks, to make sure devices are put into low power state during system suspend and brought back to full power at system resume. The prerequisite is to have all levels of a device's runtime PM callbacks to be defined through the SET_PM_RUNTIME_PM_OPS macro, which means these are available for CONFIG_PM. By using the new runtime PM helper functions especially the two scenarios below will be addressed. 1) The PM core prevents .runtime_suspend callbacks from being invoked during system suspend. That means even for a runtime PM centric subsystem and driver, the device needs to be put into low power state from a system suspend callback. Otherwise it may very well be left in full power state (runtime resumed) while the system is suspended. By using the new helper functions, we make sure to walk the hierarchy of a device's power domain, subsystem and driver. 2) Subsystems and drivers need to cope with all the combinations of CONFIG_PM_SLEEP and CONFIG_PM_RUNTIME. The two new helper functions smothly addresses this. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-03-02PM / runtime: Fetch runtime PM callbacks using a macroUlf Hansson
While fetching the proper runtime PM callback, we walk the hierarchy of device's power domains, subsystems and drivers. This is common for rpm_suspend(), rpm_idle() and rpm_resume(). Let's clean up the code by using a macro that handles this. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-10-16PM / Runtime: Respect autosuspend when idle triggers suspendUlf Hansson
For devices which don't have a .runtime_idle() callback or if it returns 0, rpm_idle() will end up in triggering a call to rpm_suspend(), thus trying to carry out a runtime suspend directly from runtime_idle(). In the above situation we want to respect devices which has enabled autosuspend, we therfore append the flag sent to rpm_suspend with RPM_AUTO. Do note that drivers still needs to update the device last busy mark, to control the delay for this circumstance. Updated runtime PM documentation accordingly. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Kevin Hilman <khilman@linaro.org> Acked-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-06-03PM / Runtime: Rework the "runtime idle" helper routineRafael J. Wysocki
The "runtime idle" helper routine, rpm_idle(), currently ignores return values from .runtime_idle() callbacks executed by it. However, it turns out that many subsystems use pm_generic_runtime_idle() which checks the return value of the driver's callback and executes pm_runtime_suspend() for the device unless that value is not 0. If that logic is moved to rpm_idle() instead, pm_generic_runtime_idle() can be dropped and its users will not need any .runtime_idle() callbacks any more. Moreover, the PCI, SCSI, and SATA subsystems' .runtime_idle() routines, pci_pm_runtime_idle(), scsi_runtime_idle(), and ata_port_runtime_idle(), respectively, as well as a few drivers' ones may be simplified if rpm_idle() calls rpm_suspend() after 0 has been returned by the .runtime_idle() callback executed by it. To reduce overall code bloat, make the changes described above. Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Kevin Hilman <khilman@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Kevin Hilman <khilman@linaro.org> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Alan Stern <stern@rowland.harvard.edu>
2013-04-12PM / Runtime: Asyncronous idle|suspend parent devices at removalUlf Hansson
For irq safe devices return the runtime reference for the parent by using the asyncronous runtime PM API. Thus we don't have to wait for it to become idle|suspended. Instead we can move on and handle the next device in queue. Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-02-23pm / runtime: force memory allocation with no I/O during Runtime PM callbcackMing Lei
Apply the introduced memalloc_noio_save() and memalloc_noio_restore() to force memory allocation with no I/O during runtime_resume/runtime_suspend callback on device with the flag of 'memalloc_noio' set. Signed-off-by: Ming Lei <ming.lei@canonical.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Decotigny <david.decotigny@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jens Axboe <axboe@kernel.dk> Cc: Minchan Kim <minchan@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oneukum@suse.de> Cc: Jiri Kosina <jiri.kosina@suse.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23pm / runtime: introduce pm_runtime_set_memalloc_noio()Ming Lei
Introduce the flag memalloc_noio in 'struct dev_pm_info' to help PM core to teach mm not allocating memory with GFP_KERNEL flag for avoiding probable deadlock. As explained in the comment, any GFP_KERNEL allocation inside runtime_resume() or runtime_suspend() on any one of device in the path from one block or network device to the root device in the device tree may cause deadlock, the introduced pm_runtime_set_memalloc_noio() sets or clears the flag on device in the path recursively. Signed-off-by: Ming Lei <ming.lei@canonical.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Oliver Neukum <oneukum@suse.de> Cc: Jiri Kosina <jiri.kosina@suse.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Greg KH <greg@kroah.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Decotigny <david.decotigny@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-22PM / Runtime: let rpm_resume() succeed if RPM_ACTIVE, even when disabled, v2Kevin Hilman
There are several drivers where the return value of pm_runtime_get_sync() is used to decide whether or not it is safe to access hardware and that don't provide .suspend() callbacks for system suspend (but may use late/noirq callbacks.) If such a driver happens to call pm_runtime_get_sync() during system suspend, after the core has disabled runtime PM, it will get the error code and will decide that the hardware should not be accessed, although this may be a wrong conclusion, depending on the state of the device when runtime PM was disabled. Drivers might work around this problem by using a test like: ret = pm_runtime_get_sync(dev); if (!ret || (ret == -EACCES && driver_private_data(dev)->suspended)) { /* access hardware */ } where driver_private_data(dev)->suspended is a flag set by the driver's .suspend() method (that would have to be added for this purpose). However, that potentially would need to be done by multiple drivers which means quite a lot of duplicated code and bloat. To avoid that we can use the observation that the core sets dev->power.is_suspended before disabling runtime PM and use that instead of the driver's private flag. Still, potentially many drivers would need to repeat that same check in quite a few places, so it's better to let the core do it. Then we can be a bit smarter and check whether or not runtime PM was disabled by the core only (disable_depth == 1) or by someone else in addition to the core (disable_depth > 1). In the former case rpm_resume() can return 1 if the runtime PM status is RPM_ACTIVE, because it means the device was active when the core disabled runtime PM. In the latter case it should still return -EACCES, because it isn't clear why runtime PM has been disabled. Tested on AM3730/Beagle-xM where a wakeup IRQ firing during the late suspend phase triggers runtime PM activity in the I2C driver since the wakeup IRQ is on an I2C-connected PMIC. [rjw: Modified whitespace to follow the file's convention.] Signed-off-by: Kevin Hilman <khilman@ti.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-08-17PM / Runtime: Check device PM QoS setting before "no callbacks" checkRafael J. Wysocki
If __dev_pm_qos_read_value(dev) returns a negative value, rpm_suspend() should return -EPERM for dev even if its power.no_callbacks flag is set. For this to happen, the device's power.no_callbacks flag has to be checked after the PM QoS check, so move the PM QoS check to rpm_check_suspend_allowed() (this will make it cover idle notifications as well as runtime suspend too). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable@vger.kernel.org
2012-08-17PM / Runtime: Clear power.deferred_resume on success in rpm_suspend()Rafael J. Wysocki
The power.deferred_resume can only be set if the runtime PM status of device is RPM_SUSPENDING and it should be cleared after its status has been changed, regardless of whether or not the runtime suspend has been successful. However, it only is cleared on suspend failure, while it may remain set on successful suspend and is happily leaked to rpm_resume() executed in that case. That shouldn't happen, so if power.deferred_resume is set in rpm_suspend() after the status has been changed to RPM_SUSPENDED, clear it before calling rpm_resume(). Then, it doesn't need to be cleared before changing the status to RPM_SUSPENDING any more, because it's always cleared after the status has been changed to either RPM_SUSPENDED (on success) or RPM_ACTIVE (on failure). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable@vger.kernel.org
2012-08-17PM / Runtime: Fix rpm_resume() return value for power.no_callbacks setRafael J. Wysocki
For devices whose power.no_callbacks flag is set, rpm_resume() should return 1 if the device's parent is already active, so that the callers of pm_runtime_get() don't think that they have to wait for the device to resume (asynchronously) in that case (the core won't queue up an asynchronous resume in that case, so there's nothing to wait for anyway). Modify the code accordingly (and make sure that an idle notification will be queued up on success, even if 1 is to be returned). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Alan Stern <stern@rowland.harvard.edu> Cc: stable@vger.kernel.org
2012-05-01PM / Runtime: Remove device fields related to suspend time, v2Rafael J. Wysocki
After the previous changes in default_stop_ok() and default_power_down_ok() for PM domains, there are two fields in struct dev_pm_info that aren't necessary any more, suspend_time and max_time_suspended_ns. Remove those fields along with all of the code that accesses them, which simplifies the runtime PM framework quite a bit. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2012-03-26PM / Runtime: don't forget to wake up waitqueue on failureAlan Stern
This patch (as1535) fixes a bug in the runtime PM core. When a runtime suspend attempt completes, whether successfully or not, the device's power.wait_queue is supposed to be signalled. But this doesn't happen in the failure pathway of rpm_suspend() when another autosuspend attempt is rescheduled. As a result, a task can get stuck indefinitely on the wait queue (I have seen this happen in testing). The patch fixes the problem by moving the wake_up_all() call up near the start of the failure code. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: <stable@vger.kernel.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-25Merge branch 'pm-runtime' into pm-for-linusRafael J. Wysocki
* pm-runtime: PM / Runtime: Use device PM QoS constraints (v2)
2011-12-21PM: Run the driver callback directly if the subsystem one is not thereRafael J. Wysocki
Make the PM core execute driver PM callbacks directly if the corresponding subsystem callbacks are not present. There are three reasons for doing that. First, it reflects the behavior of drivers/base/dd.c:really_probe() that runs the driver's .probe() callback directly if the bus type's one is not defined, so this change will remove one arbitrary difference between the PM core and the remaining parts of the driver core. Second, it will allow some subsystems, whose PM callbacks don't do anything except for executing driver callbacks, to be simplified quite a bit by removing those "forward-only" callbacks. Finally, it will allow us to remove one level of indirection in the system suspend and resume code paths where it is not necessary, which is going to lead to less debug noise with initcall_debug passed in the kernel command line (messages won't be printed for driverless devices whose subsystems don't provide PM callbacks among other things). Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-12-01PM / Runtime: Use device PM QoS constraints (v2)Rafael J. Wysocki
Make the runtime PM core use device PM QoS constraints to check if it is allowed to suspend a given device, so that an error code is returned if the device's own PM QoS constraint is negative or one of its children has already been suspended for too long. If this is not the case, the maximum estimated time the device is allowed to be suspended, computed as the minimum of the device's PM QoS constraint and the PM QoS constraints of its children (reduced by the difference between the current time and their suspend times) is stored in a new device's PM field power.max_time_suspended_ns that can be used by the device's subsystem or PM domain to decide whether or not to put the device into lower-power (and presumably higher-latency) states later (if the constraint is 0, which means "no constraint", the power.max_time_suspended_ns is set to -1). Additionally, the time of execution of the subsystem-level .runtime_suspend() callback for the device is recorded in the new power.suspend_time field for later use by the device's subsystem or PM domain along with power.max_time_suspended_ns (it also is used by the core code when the device's parent is suspended). Introduce a new helper function, pm_runtime_update_max_time_suspended(), allowing subsystems and PM domains (or device drivers) to update the power.max_time_suspended_ns field, for example after changing the power state of a suspended device. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2011-11-06Merge branch 'modsplit-Oct31_2011' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux * 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits) Revert "tracing: Include module.h in define_trace.h" irq: don't put module.h into irq.h for tracking irqgen modules. bluetooth: macroize two small inlines to avoid module.h ip_vs.h: fix implicit use of module_get/module_put from module.h nf_conntrack.h: fix up fallout from implicit moduleparam.h presence include: replace linux/module.h with "struct module" wherever possible include: convert various register fcns to macros to avoid include chaining crypto.h: remove unused crypto_tfm_alg_modname() inline uwb.h: fix implicit use of asm/page.h for PAGE_SIZE pm_runtime.h: explicitly requires notifier.h linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h miscdevice.h: fix up implicit use of lists and types stop_machine.h: fix implicit use of smp.h for smp_processor_id of: fix implicit use of errno.h in include/linux/of.h of_platform.h: delete needless include <linux/module.h> acpi: remove module.h include from platform/aclinux.h miscdevice.h: delete unnecessary inclusion of module.h device_cgroup.h: delete needless include <linux/module.h> net: sch_generic remove redundant use of <linux/module.h> net: inet_timewait_sock doesnt need <linux/module.h> ... Fix up trivial conflicts (other header files, and removal of the ab3550 mfd driver) in - drivers/media/dvb/frontends/dibx000_common.c - drivers/media/video/{mt9m111.c,ov6650.c} - drivers/mfd/ab3550-core.c - include/linux/dmaengine.h
2011-11-04PM / Runtime: Automatically retry failed autosuspendsAlan Stern
Originally, the runtime PM core would send an idle notification whenever a suspend attempt failed. The idle callback routine could then schedule a delayed suspend for some time later. However this behavior was changed by commit f71648d73c1650b8b4aceb3856bebbde6daa3b86 (PM / Runtime: Remove idle notification after failing suspend). No notifications were sent, and there was no clear mechanism to retry failed suspends. This caused problems for the usbhid driver, because it fails autosuspend attempts as long as a key is being held down. Therefore this patch (a