Changes in main.c

8fa7292f - treewide: Switch/rename to timer_delete[_sync]()

Sat, 05 Apr 2025 08:17:26 +0000

treewide: Switch/rename to timer_delete[_sync]()timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole treeover and remove the historical wrapper inlines.Conversion was done with coccinelle plus manual fixups where necessary.Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar List of files: /linux-6.15/drivers/base/power/main.c

3860cbe2 - PM: sleep: Fix bit masking operation

Wed, 19 Mar 2025 11:43:24 +0000

PM: sleep: Fix bit masking operationThe mask operation link->flags | DL_FLAG_PM_RUNTIME is always true whichis incorrect. The mask operation should be using the bit-wise &operator. Fix this.Fixes: bca84a7b93fd ("PM: sleep: Use DPM_FLAG_SMART_SUSPEND conditionally")Signed-off-by: Colin Ian King Link: https://patch.msgid.link/20250319114324.791829-1-colin.i.king@gmail.comSigned-off-by: Rafael J. Wysocki List of files: /linux-6.15/drivers/base/power/main.c

03f14440 - PM: sleep: Fix handling devices with direct_complete set on errors

Thu, 13 Mar 2025 16:00:00 +0000

PM: sleep: Fix handling devices with direct_complete set on errorsWhen dpm_suspend() fails, some devices with power.direct_complete setmay not have been handled by device_suspend() yet, so runtime PM hasnot been disabled for them yet even though power.direct_complete is set.Since device_resume() expects that runtime PM has been disabled for alldevices with power.direct_complete set, it will attempt to reenableruntime PM for the devices that have not been processed by device_suspend()which does not make sense. Had those devices had runtime PM disabledbefore device_suspend() had run, device_resume() would have inadvertentlyenable runtime PM for them, but this is not expected to happen becauseit would require ->prepare() callbacks to return positive values fordevices with runtime PM disabled, which would be invalid.In practice, this issue is most likely benign because pm_runtime_enable()will not allow the "disable depth" counter to underflow, but it causes awarning message to be printed for each affected device.To allow device_resume() to distinguish the "direct complete" devicesthat have been processed by device_suspend() from those which have notbeen handled by it, make device_suspend() set power.is_suspended for"direct complete" devices.Next, move the power.is_suspended check in device_resume() before thepower.direct_complete check in it to make it skip the "direct complete"devices that have not been handled by device_suspend().This change is based on a preliminary patch from Saravana Kannan.Fixes: aae4518b3124 ("PM / sleep: Mechanism to avoid resuming runtime-suspended devices unnecessarily")Link: https://lore.kernel.org/linux-pm/20241114220921.2529905-2-saravanak@google.com/Reported-by: Saravana Kannan Signed-off-by: Rafael J. Wysocki Reviewed-by: Saravana Kannan Link: https://patch.msgid.link/12627587.O9o76ZdvQC@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

956af869 - PM: sleep: core: Fix indentation in dpm_wait_for_children()

Wed, 12 Mar 2025 10:47:19 +0000

PM: sleep: core: Fix indentation in dpm_wait_for_children()The body of dpm_wait_for_children() is indented by 7 spaces instead of asingle TAB.Signed-off-by: Geert Uytterhoeven Link: https://patch.msgid.link/9c8ff2b103c3ba7b0d27bdc8248b05e3b1dc9551.1741776430.git.geert+renesas@glider.beSigned-off-by: Rafael J. Wysocki List of files: /linux-6.15/drivers/base/power/main.c

628ccd80 - PM: sleep: Rearrange dpm_async_fn() and async state clearing

Tue, 25 Feb 2025 16:39:40 +0000

PM: sleep: Rearrange dpm_async_fn() and async state clearingIn preparation for subsequent changes, move the power.completionreinitialization along with clearing power.work_in_progress into aseparate function called dpm_clear_async_state() and rearrangedpm_async_fn() to get rid of unnecessary indentation.No intentional functional impact.Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Link: https://patch.msgid.link/8494650.T7Z3S40VBb@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

3038b22b - PM: sleep: Rename power.async_in_progress to power.work_in_progress

Tue, 25 Feb 2025 16:38:58 +0000

PM: sleep: Rename power.async_in_progress to power.work_in_progressRename the async_in_progress field in struct dev_pm_info towork_in_progress as after subsequent changes it will mean work ingeneral rather than just async work.No functional impact.Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Link: https://patch.msgid.link/3338693.aeNJFYEL58@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

a84c2a88 - PM: core: Tweak pm_runtime_block_if_disabled() return value

Thu, 27 Feb 2025 10:49:12 +0000

PM: core: Tweak pm_runtime_block_if_disabled() return valueModify pm_runtime_block_if_disabled() to return true when runtime PMis disabled for the device, regardless of the power.last_status value.This effectively prevents "smart suspend" from being enabled fordevices with runtime PM disabled in device_prepare(), even transiently,so update the related comment in that function accordingly.If a device has runtime PM disabled in device_prepare(), it is notactually known whether or not runtime PM will be enabled for thatdevice going forward, so it is more appropriate to postpone the"smart suspend" optimization for the device in the given systemsuspend-resume cycle than to enable it and get confused goingforward.Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Link: https://patch.msgid.link/13718674.uLZWGnKmhe@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

cb88c229 - PM: sleep: Update power.smart_suspend under PM spinlock

Thu, 27 Feb 2025 10:45:52 +0000

PM: sleep: Update power.smart_suspend under PM spinlockPut the update of the power.smart_suspend device flag under the PMspinlock of the device in case multiple bit fields in struct dev_pm_infooccupy one memory location which needs to be updated via RMW every timeany of these bit fields is updated.The lock in question is already held around the power.direct_completeflag update in device_prepare() for the same reason, so this change doesnot add locking-related overhead to the code.Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Link: https://patch.msgid.link/2368159.ElGaqSPkdT@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

eeb87d17 - PM: sleep: Adjust check before setting power.must_resume

Thu, 27 Feb 2025 10:53:50 +0000

PM: sleep: Adjust check before setting power.must_resumeThe check before setting power.must_resume in device_suspend_noirq()does not take power.child_count into account, but it should do that, souse pm_runtime_need_not_resume() in it for this purpose and adjust thecomment next to it accordingly.Fixes: 107d47b2b95e ("PM: sleep: core: Simplify the SMART_SUSPEND flag handling")Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Link: https://patch.msgid.link/3353728.44csPzL39Z@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

e8195f06 - PM: sleep: Suppress sleeping parent warning in special case

Mon, 24 Feb 2025 07:00:49 +0000

PM: sleep: Suppress sleeping parent warning in special caseCurrently, if power.no_callbacks is set, device_prepare() will also setpower.direct_complete for the device. If power.direct_complete is setin device_resume(), the clearing of power.is_prepared will be skippedand if new children appear under the device at that point, a warningwill be printed.After commit (f76b168b6f11 PM: Rename dev_pm_info.in_suspend tois_prepared), power.is_prepared is generally cleared in device_resume()before invoking the resume callback for the device which allows thatcallback to add new children without triggering the warning, but thisdoes not happen for devices with power.direct_complete set.This problem is visible in USB where usb_set_interface() can be calledbefore device_complete() clears power.is_prepared for interface devicesand since ep devices are added then, the warning is printed: usb 1-1: reset high-speed USB device number 3 using ci_hdrc ep_81: PM: parent 1-1:1.1 should not be sleeping PM: resume devices took 0.936 secondsSince it is legitimate to add the ep devices at that point, thewarning above is not particularly useful, so get rid of it byclearing power.is_prepared in device_resume() for devices withpower.direct_complete set if they have no PM callbacks, in whichcase they need not actually resume for the new children to work.Suggested-by: Rafael J. Wysocki Signed-off-by: Xu Yang Link: https://patch.msgid.link/20250224070049.3338646-1-xu.yang_2@nxp.com[ rjw: New subject, changelog edits, rephrased new code comment ]Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/drivers/base/power/main.c

520a552f - PM: sleep: Avoid unnecessary checks in device_prepare_smart_suspend()

Tue, 18 Feb 2025 20:20:46 +0000

PM: sleep: Avoid unnecessary checks in device_prepare_smart_suspend()Add an optimization (on top of previous changes) to avoid callingpm_runtime_blocked(), which involves acquiring the device's PM spinlock,for devices with no PM callbacks and runtime PM "blocked".Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Link: https://patch.msgid.link/2978873.e9J7NaK4W3@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

bca84a7b - PM: sleep: Use DPM_FLAG_SMART_SUSPEND conditionally

Tue, 18 Feb 2025 20:16:48 +0000

PM: sleep: Use DPM_FLAG_SMART_SUSPEND conditionallyA recent discussion has revealed that using DPM_FLAG_SMART_SUSPENDunconditionally is generally problematic because it may lead tosituations in which the device's runtime PM information is internallyinconsistent or does not reflect its real state [1].For this reason, change the handling of DPM_FLAG_SMART_SUSPEND so thatit is only taken into account if it is consistently set by the driversof all devices having any PM callbacks throughout dependency graphs inaccordance with the following rules: - The "smart suspend" feature is only enabled for devices whose drivers ask for it (that is, set DPM_FLAG_SMART_SUSPEND) and for devices without PM callbacks unless they have never had runtime PM enabled. - The "smart suspend" feature is not enabled for a device if it has not been enabled for the device's parent unless the parent does not take children into account or it has never had runtime PM enabled. - The "smart suspend" feature is not enabled for a device if it has not been enabled for one of the device's suppliers taking runtime PM into account unless that supplier has never had runtime PM enabled.Namely, introduce a new device PM flag called smart_suspend that is onlyset if the above conditions are met and update all DPM_FLAG_SMART_SUSPENDusers to check power.smart_suspend instead of directly checking thelatter.At the same time, drop the power.set_active flage introduced recentlyin commit 3775fc538f53 ("PM: sleep: core: Synchronize runtime PM statusof parents and children") because it is now sufficient to checkpower.smart_suspend along with the dev_pm_skip_resume() return valueto decide whether or not pm_runtime_set_active() needs to be calledfor the device.Link: https://lore.kernel.org/linux-pm/CAPDyKFroyU3YDSfw_Y6k3giVfajg3NQGwNWeteJWqpW29BojhQ@mail.gmail.com/ [1]Fixes: 7585946243d6 ("PM: sleep: core: Restrict power.set_active propagation")Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Acked-by: Bjorn Helgaas # drivers/pciLink: https://patch.msgid.link/1914558.tdWV9SEqCh@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

3e5eee14 - PM: Block enabling of runtime PM during system suspend

Tue, 18 Feb 2025 20:11:42 +0000

PM: Block enabling of runtime PM during system suspendIf device_prepare() runs on a device that has never had runtimePM enabled so far, it may reasonably assume that runtime PM willnot be enabled for that device during the system suspend-resumecycle currently in progress, but this has never been guaranteed.To verify this assumption, make device_prepare() arrange fortriggering a device warning accompanied by a call trace dump ifruntime PM is enabled for such a device after it has returned.Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Link: https://patch.msgid.link/6131109.lOV4Wx5bFT@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

258e231d - PM: Rearrange documentation related to __pm_runtime_disable()

Mon, 17 Feb 2025 20:03:01 +0000

PM: Rearrange documentation related to __pm_runtime_disable()There are only two callers of __pm_runtime_disable(), one of which isdevice_suspend_late() and the other is pm_runtime_disable() that hasits own kerneldoc comment and there are no plans to add any more ofthem. Since they use different values of the __pm_runtime_disable()second parameter, the actual code behavior is different in each case,but it is all documented in the __pm_runtime_disable() kerneldoc commentwhich is not particularly straightforward.For this reason, move the information from the __pm_runtime_disable()kerneldoc comment to the pm_runtime_disable() one and into a separatecomment in device_suspend_late() and remove the __pm_runtime_disable()kerneldoc comment altogether.No functional impact.Signed-off-by: Rafael J. Wysocki Reviewed-by: Ulf Hansson Link: https://patch.msgid.link/12617588.O9o76ZdvQC@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

75859462 - PM: sleep: core: Restrict power.set_active propagation

Sat, 08 Feb 2025 17:54:28 +0000

PM: sleep: core: Restrict power.set_active propagationCommit 3775fc538f53 ("PM: sleep: core: Synchronize runtime PM status ofparents and children") exposed an issue related to simple_pm_bus_pm_opsthat uses pm_runtime_force_suspend() and pm_runtime_force_resume() asbus type PM callbacks for the noirq phases of system-wide suspend andresume.The problem is that pm_runtime_force_suspend() does not distinguishruntime-suspended devices from devices for which runtime PM has neverbeen enabled, so if it sees a device with runtime PM status set toRPM_ACTIVE, it will assume that runtime PM is enabled for that deviceand so it will attempt to suspend it with the help of its runtime PMcallbacks which may not be ready for that. As it turns out, thiscauses simple_pm_bus_runtime_suspend() to crash due to a NULL pointerdereference.Another problem related to the above commit and simple_pm_bus_pm_ops isthat setting runtime PM status of a device handled by the latter toRPM_ACTIVE will actually prevent it from being resumed becausepm_runtime_force_resume() only resumes devices with runtime PM statusset to RPM_SUSPENDED.To mitigate these issues, do not allow power.set_active to propagatebeyond the parent of the device with DPM_FLAG_SMART_SUSPEND set thatwill need to be resumed, which should be a sufficient stop-gap for thetime being, but they will need to be properly addressed in the futurebecause in general during system-wide resume it is necessary to resumeall devices in a dependency chain in which at least one device is goingto be resumed.Fixes: 3775fc538f53 ("PM: sleep: core: Synchronize runtime PM status of parents and children")Closes: https://lore.kernel.org/linux-pm/1c2433d4-7e0f-4395-b841-b8eac7c25651@nvidia.com/Reported-by: Jon Hunter Tested-by: Johan Hovold Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/6137505.lOV4Wx5bFT@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

3775fc53 - PM: sleep: core: Synchronize runtime PM status of parents and children

Tue, 28 Jan 2025 19:24:41 +0000

PM: sleep: core: Synchronize runtime PM status of parents and childrenCommit 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in theresume phase") overlooked the case in which the parent of a device withDPM_FLAG_SMART_SUSPEND set did not use that flag and could be runtime-suspended before a transition into a system-wide sleep state. In thatcase, if the child is resumed during the subsequent transition fromthat state into the working state, its runtime PM status will be set toRPM_ACTIVE, but the runtime PM status of the parent will not be updatedaccordingly, even though the parent will be resumed too, because of thedev_pm_skip_suspend() check in device_resume_noirq().Address this problem by tracking the need to set the runtime PM statusto RPM_ACTIVE during system-wide resume transitions for devices withDPM_FLAG_SMART_SUSPEND set and all of the devices depended on by them.Fixes: 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase")Closes: https://lore.kernel.org/linux-pm/Z30p2Etwf3F2AUvD@hovoldconsulting.com/Reported-by: Johan Hovold Tested-by: Manivannan Sadhasivam Signed-off-by: Rafael J. Wysocki Reviewed-by: Johan Hovold Tested-by: Johan Hovold Link: https://patch.msgid.link/12619233.O9o76ZdvQC@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

56cabb93 - PM: sleep: Allow configuring the DPM watchdog to warn earlier than panic

Thu, 09 Jan 2025 20:59:58 +0000

PM: sleep: Allow configuring the DPM watchdog to warn earlier than panicAllow configuring the DPM watchdog to warn about slow suspend/resumefunctions without causing a system panic(). This allows you to set theDPM_WATCHDOG_WARNING_TIMEOUT to something like 5 or 10 seconds to getwarnings about slow suspend/resume functions that eventually succeed.Signed-off-by: Douglas Anderson Reviewed-by: Tomasz Figa Link: https://patch.msgid.link/20250109125957.v2.1.I4554f931b8da97948f308ecc651b124338ee9603@changeid[ rjw: Subject edit ]Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/drivers/base/power/main.c

6e47c6e7 - PM: sleep: Update stale comment in device_resume()

Wed, 04 Dec 2024 13:02:04 +0000

PM: sleep: Update stale comment in device_resume()There is no function called __device_suspend() any more and it is stillmentioned in a comment in device_resume(), so update that comment.Signed-off-by: Rafael J. Wysocki Acked-by: Greg Kroah-Hartman Link: https://patch.msgid.link/2787627.mvXUDI8C0e@rjwysocki.net List of files: /linux-6.15/drivers/base/power/main.c

5b9eda2b - PM: sleep: Take advantage of %ps to simplify debug output

Fri, 05 Apr 2024 19:12:25 +0000

PM: sleep: Take advantage of %ps to simplify debug outputinitcall_debug previous and new output:...PM: calling pci_pm_suspend+0x0/0x1b0 @ 3233, parent: pci0000:00...PM: calling pci_pm_suspend @ 3233, parent: pci0000:00Signed-off-by: Len Brown Signed-off-by: Rafael J. Wysocki List of files: /linux-6.15/drivers/base/power/main.c

86205785 - PM: sleep: Call dpm_async_fn() directly in each suspend phase

Mon, 29 Jan 2024 16:29:41 +0000

PM: sleep: Call dpm_async_fn() directly in each suspend phaseSimplify the system-wide suspend of devices by invoking dpm_async_fn()directly from the main loop in each suspend phase instead of using anadditional wrapper function for running it.No intentional functional impact.Signed-off-by: Rafael J. Wysocki Reviewed-by: Stanislaw Gruszka Reviewed-by: Ulf Hansson List of files: /linux-6.15/drivers/base/power/main.c