kernel/linux.git/drivers/base/power, branch v4.4.239

PM: sleep: core: Fix the handling of pending runtime resume requests

2020-09-03T09:19:27+00:00

commit e3eb6e8fba65094328b8dca635d00de74ba75b45 upstream. It has been reported that system-wide suspend may be aborted in the absence of any wakeup events due to unforseen interactions of it with the runtume PM framework. One failing scenario is when there are multiple devices sharing an ACPI power resource and runtime-resume needs to be carried out for one of them during system-wide suspend (for example, because it needs to be reconfigured before the whole system goes to sleep). In that case, the runtime-resume of that device involves turning the ACPI power resource "on" which in turn causes runtime-resume requests to be queued up for all of the other devices sharing it. Those requests go to the runtime PM workqueue which is frozen during system-wide suspend, so they are not actually taken care of until the resume of the whole system, but the pm_runtime_barrier() call in __device_suspend() sees them and triggers system wakeup events for them which then cause the system-wide suspend to be aborted if wakeup source objects are in active use. Of course, the logic that leads to triggering those wakeup events is questionable in the first place, because clearly there are cases in which a pending runtime resume request for a device is not connected to any real wakeup events in any way (like the one above). Moreover, it is racy, because the device may be resuming already by the time the pm_runtime_barrier() runs and so if the driver doesn't take care of signaling the wakeup event as appropriate, it will be lost. However, if the driver does take care of that, the extra pm_wakeup_event() call in the core is redundant. Accordingly, drop the conditional pm_wakeup_event() call fron __device_suspend() and make the latter call pm_runtime_barrier() alone. Also modify the comment next to that call to reflect the new code and extend it to mention the need to avoid unwanted interactions between runtime PM and system-wide device suspend callbacks. Fixes: 1e2ef05bb8cf8 ("PM: Limit race conditions between runtime PM and system sleep (v2)") Signed-off-by: Rafael J. Wysocki Acked-by: Alan Stern Reported-by: Utkarsh H Patel Tested-by: Utkarsh H Patel Tested-by: Pengfei Xu Cc: All applicable Signed-off-by: Greg Kroah-Hartman

PM / core: Propagate dev->power.wakeup_path when no callbacks

2019-06-11T10:24:00+00:00

[ Upstream commit dc351d4c5f4fe4d0f274d6d660227be0c3a03317 ] The dev->power.direct_complete flag may become set in device_prepare() in case the device don't have any PM callbacks (dev->power.no_pm_callbacks is set). This leads to a broken behaviour, when there is child having wakeup enabled and relies on its parent to be used in the wakeup path. More precisely, when the direct complete path becomes selected for the child in __device_suspend(), the propagation of the dev->power.wakeup_path becomes skipped as well. Let's address this problem, by checking if the device is a part the wakeup path or has wakeup enabled, then prevent the direct complete path from being used. Reported-by: Loic Pallardy Signed-off-by: Ulf Hansson [ rjw: Comment cleanup ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin

PM / wakeup: Rework wakeup source timer cancellation

2019-03-23T07:44:39+00:00

commit 1fad17fb1bbcd73159c2b992668a6957ecc5af8a upstream. If wakeup_source_add() is called right after wakeup_source_remove() for the same wakeup source, timer_setup() may be called for a potentially scheduled timer which is incorrect. To avoid that, move the wakeup source timer cancellation from wakeup_source_drop() to wakeup_source_remove(). Moreover, make wakeup_source_remove() clear the timer function after canceling the timer to let wakeup_source_not_registered() treat unregistered wakeup sources in the same way as the ones that have never been registered. Signed-off-by: Viresh Kumar Cc: 4.4+ # 4.4+ [ rjw: Subject, changelog, merged two patches together ] Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM / core: Clear the direct_complete flag on errors

2018-10-13T07:11:32+00:00

commit 69e445ab8b66a9f30519842ef18be555d3ee9b51 upstream. If __device_suspend() runs asynchronously (in which case the device passed to it is in dpm_suspended_list at that point) and it returns early on an error or pending wakeup, and the power.direct_complete flag has been set for the device already, the subsequent device_resume() will be confused by that and it will call pm_runtime_enable() incorrectly, as runtime PM has not been disabled for the device by __device_suspend(). To avoid that, clear power.direct_complete if __device_suspend() is not going to disable runtime PM for the device before returning. Fixes: aae4518b3124 (PM / sleep: Mechanism to avoid resuming runtime-suspended devices unnecessarily) Reported-by: Al Cooper Tested-by: Al Cooper Reviewed-by: Ulf Hansson Cc: 3.16+ # 3.16+ Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM / sleep: declare __tracedata symbols as char[] rather than char

2018-01-31T11:06:08+00:00

commit f97238373b8662a6d580e204df2e7bcbfa43e27a upstream. Accessing more than one byte from a symbol declared simply 'char' is undefined behavior, as reported by UBSAN: UBSAN: Undefined behaviour in drivers/base/power/trace.c:178:18 load of address ffffffff8203fc78 with insufficient space for an object of type 'char' Avoid this by declaring the symbols as arrays. Signed-off-by: Eric Biggers Signed-off-by: Rafael J. Wysocki Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman

PM / OPP: Add missing of_node_put(np)

2017-11-30T08:37:25+00:00

commit 7978db344719dab1e56d05e6fc04aaaddcde0a5e upstream. The for_each_available_child_of_node() loop in _of_add_opp_table_v2() doesn't drop the reference to "np" on errors. Fix that. Fixes: 274659029c9d (PM / OPP: Add support to parse "operating-points-v2" bindings) Signed-off-by: Tobias Jordan [ VK: Improved commit log. ] Signed-off-by: Viresh Kumar Reviewed-by: Stephen Boyd Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM / wakeirq: report a wakeup_event on dedicated wekup irq

2017-11-08T09:06:28+00:00

[ Upstream commit 09bb6e93956ae5175b96905b723ec879c3ca0765 ] There are two reasons for reporting wakeup event when dedicated wakeup IRQ is triggered: - wakeup events accounting, so proper statistical data will be displayed in sysfs and debugfs; - there are small window when System is entering suspend during which dedicated wakeup IRQ can be lost: dpm_suspend_noirq() |- device_wakeup_arm_wake_irqs() |- dev_pm_arm_wake_irq(X) |- IRQ is enabled and marked as wakeup source [1]... |- suspend_device_irqs() |- suspend_device_irq(X) |- irqd_set(X, IRQD_WAKEUP_ARMED); |- wakup IRQ armed The wakeup IRQ can be lost if it's triggered at point [1] and not armed yet. Hence, fix above cases by adding simple pm_wakeup_event() call in handle_threaded_wake_irq(). Fixes: 4990d4fe327b (PM / Wakeirq: Add automated device wake IRQ handling) Signed-off-by: Grygorii Strashko Tested-by: Keerthy [ tony@atomide.com: added missing return to avoid warnings ] Tested-by: Tony Lindgren Signed-off-by: Tony Lindgren Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

PM / Domains: defer dev_pm_domain_set() until genpd->attach_dev succeeds if present

2017-08-07T02:19:42+00:00

commit 975e83cfb8dc16e7a2fdc58188c77c0c605876c2 upstream. If the genpd->attach_dev or genpd->power_on fails, genpd_dev_pm_attach may return -EPROBE_DEFER initially. However genpd_alloc_dev_data sets the PM domain for the device unconditionally. When subsequent attempts are made to call genpd_dev_pm_attach, it may return -EEXISTS checking dev->pm_domain without re-attempting to call attach_dev or power_on. platform_drv_probe then attempts to call drv->probe as the return value -EEXIST != -EPROBE_DEFER, which may end up in a situation where the device is accessed without it's power domain switched on. Fixes: f104e1e5ef57 (PM / Domains: Re-order initialization of generic_pm_domain_data) Signed-off-by: Sudeep Holla Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM / Domains: Fix unsafe iteration over modified list of domain providers

2017-07-27T22:06:04+00:00

commit b556b15dc04e9b9b98790f04c21acf5e24f994b2 upstream. of_genpd_del_provider() iterates over list of domain provides and removes matching element thus it has to use safe version of list iteration. Fixes: aa42240ab254 (PM / Domains: Add generic OF-based PM domain look-up) Signed-off-by: Krzysztof Kozlowski Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

PM / Domains: Fix unsafe iteration over modified list of device links

2017-07-27T22:06:04+00:00

commit c6e83cac3eda5f7dd32ee1453df2f7abb5c6cd46 upstream. pm_genpd_remove_subdomain() iterates over domain's master_links list and removes matching element thus it has to use safe version of list iteration. Fixes: f721889ff65a ("PM / Domains: Support for generic I/O PM domains (v8)") Signed-off-by: Krzysztof Kozlowski Acked-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman