kernel/drivers/base/power/runtime.c, branch linux-4.1.y

PM / runtime: Avoid false-positive warnings from might_sleep_if()

2017-06-26T02:02:20Z

[ Upstream commit a9306a63631493afc75893a4ac405d4e1cbae6aa ] 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: [] 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 Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

PM / Runtime: Fix error path in pm_runtime_force_resume()

2016-06-03T23:15:31Z

[ Upstream commit 0ae3aeefabbeef26294e7a349b51f1c761d46c9f ] 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 Reviewed-by: Linus Walleij Cc: 3.15+ # 3.15+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

PM: Drop CONFIG_PM_RUNTIME from the driver core

2014-12-03T23:46:58Z

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 Acked-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki

PM / Runtime: Rework RPM get callback routines

2014-11-05T23:49:57Z

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 Acked-by: Pavel Machek Reviewed-by: Ulf Hansson Acked-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki

Merge branches 'pm-runtime' and 'pm-sleep'

2014-03-20T12:25:54Z

* pm-runtime: PM / Runtime: Update runtime_idle() documentation for return value meaning * pm-sleep: PM / sleep: Correct whitespace errors in 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

PM / Runtime: Add missing "it" in comment

2014-03-11T23:54:53Z

Signed-off-by: Geert Uytterhoeven Acked-by: Pavel Machek Signed-off-by: Rafael J. Wysocki

PM: Add pm_runtime_suspend|resume_force functions

2014-03-01T23:18:15Z

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 Signed-off-by: Rafael J. Wysocki

PM / runtime: Fetch runtime PM callbacks using a macro

2014-03-01T23:18:15Z

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 Signed-off-by: Rafael J. Wysocki

PM / Runtime: Respect autosuspend when idle triggers suspend

2013-10-16T00:06:57Z

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 Acked-by: Kevin Hilman Acked-by: Alan Stern Signed-off-by: Rafael J. Wysocki

PM / Runtime: Rework the "runtime idle" helper routine

2013-06-03T19:49:52Z

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 Tested-by: Kevin Hilman Signed-off-by: Rafael J. Wysocki Acked-by: Kevin Hilman Reviewed-by: Ulf Hansson Acked-by: Alan Stern