Re: [PATCH 1/5] drm/panel-edp: Use ktime_get_boottime for delays

From: Doug Anderson
Date: Tue Nov 29 2022 - 17:28:55 EST


Hi,

On Thu, Nov 17, 2022 at 1:14 PM Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
>
> Hi,
>
> On Thu, Nov 17, 2022 at 12:39 PM Drew Davenport <ddavenport@xxxxxxxxxxxx> wrote:
> >
> > ktime_get is based on CLOCK_MONOTONIC which stops on suspend. On
> > suspend, the time that the panel was powerd off is recorded with
> > ktime_get, and on resume this time is compared to the current ktime_get
> > time to determine if the driver should wait for the panel to power down
> > completely before re-enabling it.
> >
> > Because we're using ktime_get, this delay doesn't account for the time
> > that the device is suspended, during which the power down delay may have
> > already elapsed.
> >
> > Change to use ktime_get_boottime throughout, which uses CLOCK_BOOTTIME
> > which does not stop when suspended. This ensures that the resume path
> > will not be delayed if the power off delay has already been met while
> > the device is suspended.
> >
> > Signed-off-by: Drew Davenport <ddavenport@xxxxxxxxxxxx>
> >
> > ---
> >
> > drivers/gpu/drm/panel/panel-edp.c | 8 ++++----
> > 1 file changed, 4 insertions(+), 4 deletions(-)
>
> Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

Pushed to drm-misc-next:

fa8e91b12697 drm/panel-edp: Use ktime_get_boottime for delays