Re: [PATCH v2 0/9] PM: sleep: core: Rearrange the handling of driver power management flags

[Rafael J. Wysocki]

On Tue, Apr 21, 2020 at 12:30 PM Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
>
> On Sat, 18 Apr 2020 at 19:11, Rafael J. Wysocki <rjw@xxxxxxxxxxxxx> wrote:
> >
> > Hi,
> >
> > This is an update including some fixes and extra patches based on the
> > continuation of the discussion [1].
> >
> > On Friday, April 10, 2020 5:46:27 PM CEST Rafael J. Wysocki wrote:
> > > Hi Alan,
> > >
> > > Following our recent discussion regarding the DPM_FLAG_* family of flags [1],
> > > I have decided to follow some of your recommendations and make changes to the
> > > core code handling those flags.
> > >
> > > The purpose of this is basically to make the code more consistent internally,
> > > easier to follow and better documented.
> > >
> > > First of all, patch [1/7] changes the PM core to skip driver-level "late"
> > > and "noirq" suspend callbacks for devices with SMART_SUSPEND set if they are
> > > still runtime-suspended during the "late" system-wide suspend phase (without
> > > the patch it does that only if subsystem-level late/noirq/early suspend/resume
> > > callbacks are not present for the device, which is demonstrably inconsistent)
> > > and updates the resume part of the code accordingly (it doesn't need to check
> > > whether or not the subsystem-level callbacks are present any more).
> > >
> > > The next patch, [2/7], is purely cosmetic and its only purpose is to reduce
> > > the LOC number and move related pieces of code closer to each other.
> >
> > The first two patches have not changed.
> >
> > > Patch [3/7] changes the PM core so that it doesn't skip any subsystem-level
> > > callbacks during system-wide resume (without the patch they may be skipped in
> > > the "early resume" and "resume" phases due to LEAVE_SUSPENDED being set which
> > > may be problematic) and to always run the driver's ->resume callback if the
> > > corresponding subsystem-level callback is not present (without the patch it
> > > may be skipped if LEAVE_SUSPENDED is set) to let it reverse the changes made
> > > by the driver's ->suspend callback (which always runs too) if need be.
> >
> > The difference between this one and patch [3/9] in the v2 is the fixed
> > definition of dev_pm_may_skip_resume(), renamed to dev_pm_skip_resume() by
> > one of the next patches.
> >
> > Patch [4/9] changes the handling of the power.may_skip_resume flag to set it
> > to 'true' by default and updates the subsystems aware of it to clear it when
> > they don't want devices to stay in suspend.
> >
> > > Patches [4-6/7] rename one function in the PM core and two driver PM flags to
> > > make their names better reflect their purpose.
> >
> > These are patches [5/9] and [7-8/9] in the v2 and patch [6/9] renames
> > dev_pm_smart_suspend_and_suspended() to dev_pm_skip_suspend().
> >
> > > Finally, patch [7/7] updates the documentation of the driver PM flags to
> > > reflect the new code flows.
> >
> > This patch [9/9] now and it has been updated to reflect the new code changes.
> >
> > The pm-sleep-core branch:
> >
> >   git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git \
> >   pm-sleep-core
> >
> > contains the v2 now.
> >
> > Cheers!
>
> Rafael, apologize for taking some time to review and respond. I
> noticed you have queued this up on your next branch by now, good.
>
> In any case, I have looked through the series and I think it looks good, thanks!

Thanks for letting me know!

Cheers!