[PATCH 2/4] drm/panel-elida-kd35t133: hold panel in reset for unprepare

[Chris Morgan]

On Wed, Nov 15, 2023 at 01:38:11PM -0800, Jessica Zhang wrote:
> 
> 
> On 11/15/2023 7:26 AM, Chris Morgan wrote:
> > From: Chris Morgan <macromorgan at hotmail.com>
> > 
> > For devices like the Anbernic RG351M and RG351P the panel is wired to
> > an always on regulator. When the device suspends and wakes up, there
> > are some slight artifacts on the screen that go away over time. If
> > instead we hold the panel in reset status after it is unprepared,
> > this does not happen.
> 
> Hi Chris,
> 
> LGTM, though if this is fixing something maybe we can add
> 
> Fixes: 5b6603360c12 ("drm/panel: add panel driver for Elida KD35T133
> panels")

It *may* fix an intermittent issue with the panel resuming from
suspend, but it really more solves an issue with devices for which
we're still adding support.

Should I still tag it as a "fixes" then?

Thank you.

> 
> > 
> > Signed-off-by: Chris Morgan <macromorgan at hotmail.com>
> 
> Reviewed-by: Jessica Zhang <quic_jesszhan at quicinc.com>
> 
> Thanks,
> 
> Jessica Zhang
> 
> > ---
> >   drivers/gpu/drm/panel/panel-elida-kd35t133.c | 2 ++
> >   1 file changed, 2 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/panel/panel-elida-kd35t133.c b/drivers/gpu/drm/panel/panel-elida-kd35t133.c
> > index 6cd8536c09ff..f1fc4a26f447 100644
> > --- a/drivers/gpu/drm/panel/panel-elida-kd35t133.c
> > +++ b/drivers/gpu/drm/panel/panel-elida-kd35t133.c
> > @@ -104,6 +104,8 @@ static int kd35t133_unprepare(struct drm_panel *panel)
> >   		return ret;
> >   	}
> > +	gpiod_set_value_cansleep(ctx->reset_gpio, 1);
> > +
> >   	regulator_disable(ctx->iovcc);
> >   	regulator_disable(ctx->vdd);
> > -- 
> > 2.34.1
> >