Re: [PATCH v4 01/39] drm/msm/dp: remove cached drm_edid from panel

[Dmitry Baryshkov]

On Tue, May 19, 2026 at 03:27:00PM +0800, Yongxing Mou wrote:
> 
> 
> On 4/10/2026 9:52 PM, Dmitry Baryshkov wrote:
> > On Fri, Apr 10, 2026 at 05:33:36PM +0800, Yongxing Mou wrote:
> > > The cached drm_edid seems unnecessary here. Use the drm_edid pointer
> > > directly in the plug stage instead of caching it. Remove the cached
> > > drm_edid and the corresponding oneliner to simplify the code.
> > > 
> > > Signed-off-by: Yongxing Mou <yongxing.mou@xxxxxxxxxxxxxxxx>
> > > ---
> > >   drivers/gpu/drm/msm/dp/dp_display.c | 27 +++++++++++-------
> > >   drivers/gpu/drm/msm/dp/dp_panel.c   | 57 ++++---------------------------------
> > >   drivers/gpu/drm/msm/dp/dp_panel.h   | 13 +++------
> > >   3 files changed, 26 insertions(+), 71 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> > > index 5c6a24ec140d..e28cc1bbb5b1 100644
> > > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > > @@ -268,6 +268,7 @@ static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp)
> > >   	const struct drm_display_info *info = &connector->display_info;
> > >   	int rc = 0;
> > >   	u8 dpcd[DP_RECEIVER_CAP_SIZE];
> > > +	const struct drm_edid *drm_edid;
> > >   	rc = drm_dp_read_dpcd_caps(dp->aux, dpcd);
> > >   	if (rc)
> > > @@ -275,10 +276,20 @@ static int msm_dp_display_process_hpd_high(struct msm_dp_display_private *dp)
> > >   	dp->link->lttpr_count = msm_dp_display_lttpr_init(dp, dpcd);
> > > -	rc = msm_dp_panel_read_sink_caps(dp->panel, connector);
> > > +	rc = msm_dp_panel_read_link_caps(dp->panel, connector);
> > >   	if (rc)
> > >   		goto end;
> > > +	drm_edid = drm_edid_read_ddc(connector, &dp->aux->ddc);
> > 
> > Where is it free?
> > 
> Ohh, i miss it, will update next version
> > > +	drm_edid_connector_update(connector, drm_edid);
> > > +
> > > +	if (!drm_edid) {
> > > +		DRM_ERROR("panel edid read failed\n");
> > > +		/* check edid read fail is due to unplug */
> > > +		if (!msm_dp_aux_is_link_connected(dp->aux))
> > 
> > Does this work for USB-C AltMode usecase?
> > 
> For USB-C DP, i think it always TRUE, here should already existed before
> this patch..

I'd expect the answer without the 'i think' part.

> > > +			return -ETIMEDOUT;
> > > +	}
> > > +
> > >   	msm_dp_link_process_request(dp->link);
> > >   	if (!dp->msm_dp_display.is_edp)
> > 
> 

-- 
With best wishes
Dmitry