Re: [PATCH RFC] suspend: Prevent might sleep splats

[Sebastian Andrzej Siewior]

On 2018-05-24 17:07:16 [+0200], Rafael J. Wysocki wrote:
> On Thu, May 24, 2018 at 4:24 PM, Sebastian Andrzej Siewior
> <bigeasy@xxxxxxxxxxxxx> wrote:
> > From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> >
> > timekeeping suspend/resume calls read_persistent_clock() which takes
> > rtc_lock. That results in might sleep warnings because at that point
> > we run with interrupts disabled.
> >
> > We cannot convert rtc_lock to a raw spinlock as that would trigger
> > other might sleep warnings.
> >
> > As a workaround we disable the might sleep warnings by setting
> > system_state to SYSTEM_SUSPEND before calling sysdev_suspend() and
> > restoring it to SYSTEM_RUNNING afer sysdev_resume().
> >
> > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
> 
> Hmm.  Don't we also need to cover suspend-to-idle?

Well, if you agree with the approach then I would look into it.

Sebastian