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

From: Stephen Boyd
Date: Thu Jul 08 2021 - 03:14:34 EST


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?

> dp_link_send_test_response(panel->link);