drm/msm/dp: skip validity check for DP CTS EDID checksum

[ Upstream commit a251c9d8e30833b260101edb9383b176ee2b7cb1 ]

The DP CTS test for EDID last block checksum expects the checksum for
the last block, invalid or not. Skip the validity check.

For the most part (*), the EDIDs returned by drm_get_edid() will be
valid anyway, and there's the CTS workaround to get the checksum for
completely invalid EDIDs. See commit 7948fe12d47a ("drm/msm/dp: return
correct edid checksum after corrupted edid checksum read").

This lets us remove one user of drm_edid_block_valid() with hopes the
function can be removed altogether in the future.

(*) drm_get_edid() ignores checksum errors on CTA extensions.

Cc: Abhinav Kumar <quic_abhinavk@quicinc.com>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Kuogee Hsieh <khsieh@codeaurora.org>
Cc: Marijn Suijten <marijn.suijten@somainline.org>
Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Stephen Boyd <swboyd@chromium.org>
Cc: linux-arm-msm@vger.kernel.org
Cc: freedreno@lists.freedesktop.org
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
Reviewed-by: Kuogee Hsieh <quic_khsieh@quicinc.com>
Patchwork: https://patchwork.freedesktop.org/patch/555361/
Link: https://lore.kernel.org/r/20230901142034.580802-1-jani.nikula@intel.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
index 5149ceb..d380866 100644 (file)
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -266,26 +266,9 @@ int dp_panel_get_modes(struct dp_panel *dp_panel,
 
 static u8 dp_panel_get_edid_checksum(struct edid *edid)
 {
-       struct edid *last_block;
-       u8 *raw_edid;
-       bool is_edid_corrupt = false;
+       edid += edid->extensions;
 
-       if (!edid) {
-               DRM_ERROR("invalid edid input\n");
-               return 0;
-       }
-
-       raw_edid = (u8 *)edid;
-       raw_edid += (edid->extensions * EDID_LENGTH);
-       last_block = (struct edid *)raw_edid;
-
-       /* block type extension */
-       drm_edid_block_valid(raw_edid, 1, false, &is_edid_corrupt);
-       if (!is_edid_corrupt)
-               return last_block->checksum;
-
-       DRM_ERROR("Invalid block, no checksum\n");
-       return 0;
+       return edid->checksum;
 }
 
 void dp_panel_handle_sink_request(struct dp_panel *dp_panel)