Re: [PATCH 5/7] drm/msm/dp: return correct edid checksum after corrupted edid checksum read

[khsieh]

On 2021-07-08 00:14, Stephen Boyd wrote:
> Quoting Kuogee Hsieh (2021-07-06 10:20:18)
> > Response with correct edid checksum saved at connector after corrupted 
> > edid
> > checksum read. This fixes Link Layer CTS cases 4.2.2.3, 4.2.2.6.
> >
> > Signed-off-by: Kuogee Hsieh <khsieh@xxxxxxxxxxxxxx>
> > ---
> >  drivers/gpu/drm/msm/dp/dp_panel.c | 9 +++++++--
> >  1 file changed, 7 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c 
> > b/drivers/gpu/drm/msm/dp/dp_panel.c
> > index 88196f7..0fdb551 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_panel.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_panel.c
> > @@ -271,7 +271,7 @@ static u8 dp_panel_get_edid_checksum(struct edid 
> > *edid)
> >  {
> >         struct edid *last_block;
> >         u8 *raw_edid;
> > -       bool is_edid_corrupt;
> > +       bool is_edid_corrupt = false;
> >
> >         if (!edid) {
> >                 DRM_ERROR("invalid edid input\n");
> > @@ -303,7 +303,12 @@ void dp_panel_handle_sink_request(struct dp_panel 
> > *dp_panel)
> >         panel = container_of(dp_panel, struct dp_panel_private, 
> > dp_panel);
> >
> >         if (panel->link->sink_request & DP_TEST_LINK_EDID_READ) {
> > -               u8 checksum = 
> > dp_panel_get_edid_checksum(dp_panel->edid);
> > +               u8 checksum;
> > +
> > +               if (dp_panel->edid)
> > +                       checksum = 
> > dp_panel_get_edid_checksum(dp_panel->edid);
> > +               else
> > +                       checksum = 
> > dp_panel->connector->real_edid_checksum;
> >
> >                 dp_link_send_edid_checksum(panel->link, checksum);
>
> It looks like this can be drm_dp_send_real_edid_checksum()? Then we
> don't have to look at the connector internals sometimes and can drop
> dp_panel_get_edid_checksum() entirely?
you still need to pass read edid checksum into 
drm_dp_send_real_edid_checksum().
> >                 dp_link_send_test_response(panel->link);