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* [PATCH] PM: sleep: core: Avoid setting power.must_resume to false
@ 2021-07-26 15:24 Prasad Sodagudi
  2021-08-03 17:16 ` Greg KH
  0 siblings, 1 reply; 7+ messages in thread
From: Prasad Sodagudi @ 2021-07-26 15:24 UTC (permalink / raw)
  To: rjw, len.brown, pavel, gregkh; +Cc: linux-pm, linux-kernel, Prasad Sodagudi

There are variables(power.may_skip_resume and dev->power.must_resume)
and DPM_FLAG_MAY_SKIP_RESUME flags to control the resume of devices after
a system wide suspend transition.

Setting the DPM_FLAG_MAY_SKIP_RESUME flag means that the driver allows
its "noirq" and "early" resume callbacks to be skipped if the device
can be left in suspend after a system-wide transition into the working
state. PM core determines that the driver's "noirq" and "early" resume
callbacks should be skipped or not with dev_pm_skip_resume() function by
checking power.may_skip_resume variable.

power.must_resume variable is getting set to false in __device_suspend()
function without checking device's DPM_FLAG_MAY_SKIP_RESUME and
dev->power.usage_count variables. This is leading to failure to call
resume handler for some of the devices suspended in early suspend phase.
So check device's DPM_FLAG_MAY_SKIP_RESUME flag before
setting power.must_resume variable.

Signed-off-by: Prasad Sodagudi <>
 drivers/base/power/main.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index d568772..8eebc4d 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -1642,7 +1642,11 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 	dev->power.may_skip_resume = true;
-	dev->power.must_resume = false;
+	if ((atomic_read(&dev->power.usage_count) <= 1) &&
+			(dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME)))
+		dev->power.must_resume = false;
+	else
+		dev->power.must_resume = true;
 	dpm_watchdog_set(&wd, dev);
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2021-08-08 17:36 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-26 15:24 [PATCH] PM: sleep: core: Avoid setting power.must_resume to false Prasad Sodagudi
2021-08-03 17:16 ` Greg KH
2021-08-06 15:07   ` psodagud
2021-08-06 15:16     ` Greg KH
2021-08-07  6:00     ` Greg KH
2021-08-08 16:10       ` [PATCH v2] " Prasad Sodagudi
2021-08-08 17:36         ` Greg KH

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