| Message ID | 1631013863-43141-1-git-send-email-psodagud@codeaurora.org (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | [v5] PM: sleep: core: Avoid setting power.must_resume to false | expand |
On Tue, Sep 7, 2021 at 1:24 PM Prasad Sodagudi <psodagud@codeaurora.org> wrote: > > 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 settings. > In problematic scenario, where all the devices in the suspend_late > stage are successful and some device can fail to suspend in > suspend_noirq phase. So some devices successfully suspended in suspend_late > stage are not getting chance to execute __device_suspend_noirq() > to set dev->power.must_resume variable to true and not getting > resumed in early_resume phase. > > Add a check for device's DPM_FLAG_MAY_SKIP_RESUME flag before > setting power.must_resume variable in __device_suspend function. > > Fixes: 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase") > Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org> > --- > V4 -> V5: Fix coding style > V3 -> V4: Remove dev->power.usage_count variable check > V2 -> V3: Format issues patch posting > V1 -> V2: Fixed indentation and commit text to include scenario > drivers/base/power/main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c > index d568772..cbea78e 100644 > --- a/drivers/base/power/main.c > +++ b/drivers/base/power/main.c > @@ -1642,7 +1642,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) > } > > dev->power.may_skip_resume = true; > - dev->power.must_resume = false; > + dev->power.must_resume = !dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME); > > dpm_watchdog_set(&wd, dev); > device_lock(dev); > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project Applied as 5.15-rc material, thanks!
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index d568772..cbea78e 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -1642,7 +1642,7 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async) } dev->power.may_skip_resume = true; - dev->power.must_resume = false; + dev->power.must_resume = !dev_pm_test_driver_flags(dev, DPM_FLAG_MAY_SKIP_RESUME); dpm_watchdog_set(&wd, dev); device_lock(dev);
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 settings. In problematic scenario, where all the devices in the suspend_late stage are successful and some device can fail to suspend in suspend_noirq phase. So some devices successfully suspended in suspend_late stage are not getting chance to execute __device_suspend_noirq() to set dev->power.must_resume variable to true and not getting resumed in early_resume phase. Add a check for device's DPM_FLAG_MAY_SKIP_RESUME flag before setting power.must_resume variable in __device_suspend function. Fixes: 6e176bf8d461 ("PM: sleep: core: Do not skip callbacks in the resume phase") Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org> --- V4 -> V5: Fix coding style V3 -> V4: Remove dev->power.usage_count variable check V2 -> V3: Format issues patch posting V1 -> V2: Fixed indentation and commit text to include scenario drivers/base/power/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)