Messages in this thread Patch in this message |  | | From | "Rafael J. Wysocki" <> | Subject | Re: [PATCH] PM / core: Fix extra pm_runtime_enable on resume | Date | Wed, 03 Oct 2018 10:30:14 +0200 |
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On Wednesday, September 26, 2018 12:10:55 AM CEST Al Cooper wrote: > Matching pm_runtime_disable/pm_runtime_enable routines should be > called for "direct_complete" devices during suspend/resume and there > are cases where the pm_runtime_disable is skipped during suspend but > pm_runtime_enable is still called during resume. This is a problem > because the runtime enable state is really a counter and this can > incorrectly enable pm_runtime when it should not be enabled. This > happens for any direct_complete device doing an async suspend after > the global variable "async_error" is set (which is set by any sync > or async device's suspend error or early wake condition).
So the bug is simply that the direct_complete flag is not cleared when we are going to bail out of __device_suspend() early due to an error or wakeup.
The patch below should fix it then (without adding extra flags to struct dev_pm_info), shouldn't it?
--- drivers/base/power/main.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
Index: linux-pm/drivers/base/power/main.c =================================================================== --- linux-pm.orig/drivers/base/power/main.c +++ linux-pm/drivers/base/power/main.c @@ -1713,8 +1713,10 @@ static int __device_suspend(struct devic dpm_wait_for_subordinate(dev, async); - if (async_error) + if (async_error) { + dev->power.direct_complete = false; goto Complete; + } /* * If a device configured to wake up the system from sleep states @@ -1726,6 +1728,7 @@ static int __device_suspend(struct devic pm_wakeup_event(dev, 0); if (pm_wakeup_pending()) { + dev->power.direct_complete = false; async_error = -EBUSY; goto Complete; }
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