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

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 <[email protected]>
Cc: Dmitry Baryshkov <[email protected]>
Cc: Kuogee Hsieh <[email protected]>
Cc: Marijn Suijten <[email protected]>
Cc: Rob Clark <[email protected]>
Cc: Sean Paul <[email protected]>
Cc: Stephen Boyd <[email protected]>
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Jani Nikula <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Reviewed-by: Abhinav Kumar <[email protected]>
Reviewed-by: Kuogee Hsieh <[email protected]>
Patchwork: https://patchwork.freedesktop.org/patch/555361/
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Dmitry Baryshkov <[email protected]>

1 files changed, 2 insertions, 19 deletions

diff --git a/drivers/gpu/drm/msm/dp/dp_panel.c b/drivers/gpu/drm/msm/dp/dp_panel.c
index 97ba41593820..3957c567c730 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -219,26 +219,9 @@ 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)