On Thu, Sep 25, 2025 at 7:51 PM Rafael J. Wysocki <[email protected]> wrote:
>
> On Thu, Sep 25, 2025 at 7:47 PM Rafael J. Wysocki <[email protected]> wrote:
> >
> > On Thu, Sep 25, 2025 at 5:59 PM Mario Limonciello (AMD)
> > <[email protected]> wrote:
> > >
> > > Hybrid sleep will hibernate the system followed by running through
> > > the suspend routine.  Since both the hibernate and the suspend routine
> > > will call pm_restrict_gfp_mask(), pm_restore_gfp_mask() must be called
> > > before starting the suspend sequence.
> > >
> > > Add an explicit call to pm_restore_gfp_mask() to power_down() before
> > > the suspend sequence starts. Don't call pm_restore_gfp_mask() when
> > > exiting suspend sequence it is already called:
> > >
> > > ```
> > > power_down()
> > > ->suspend_devices_and_enter()
> > > -->dpm_resume_end()
> > > ```
> > >
> > > Reported-by: Ionut Nechita <[email protected]>
> > > Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4573
> > > Tested-by: Ionut Nechita <[email protected]>
> > > Fixes: 12ffc3b1513eb ("PM: Restrict swap use to later in the suspend 
> > > sequence")
> > > Tested-by: Kenneth Crudup <[email protected]>
> > > Acked-by: Alex Deucher <[email protected]>
> > > Signed-off-by: Mario Limonciello (AMD) <[email protected]>
> > > ---
> > > v2:
> > >  * Move under CONFIG_SUSPEND scope (LKP robot)
> > >  * Add tags
> > > ---
> > >  kernel/power/hibernate.c | 11 ++++++++++-
> > >  1 file changed, 10 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> > > index 2f66ab4538231..52c1818749724 100644
> > > --- a/kernel/power/hibernate.c
> > > +++ b/kernel/power/hibernate.c
> > > @@ -695,6 +695,7 @@ static void power_down(void)
> > >
> > >  #ifdef CONFIG_SUSPEND
> > >         if (hibernation_mode == HIBERNATION_SUSPEND) {
> > > +               pm_restore_gfp_mask();
> > >                 error = suspend_devices_and_enter(mem_sleep_current);
> > >                 if (error) {
> > >                         hibernation_mode = hibernation_ops ?
> > > @@ -862,7 +863,15 @@ int hibernate(void)
> > >                                 power_down();
> > >                 }
> > >                 in_suspend = 0;
> > > -               pm_restore_gfp_mask();
> > > +               switch (hibernation_mode) {
> > > +#ifdef CONFIG_SUSPEND
> > > +               case HIBERNATION_SUSPEND:
> > > +                       break;
> > > +#endif
> > > +               default:
> > > +                       pm_restore_gfp_mask();
> > > +                       break;
> > > +               }
> >
> > You're breaking HIBERNATION_TEST_RESUME here AFAICS
>
> Well, not really because of the hibernation_mode check.
>
> > and power_down() doesn't return.
>
> But this still is true.

Well, except when it does HIBERNATION_SUSPEND.

But can you just make power_down() call pm_restrict_gfp_mask() before
returning and leave the code in hibernate() as is?

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