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* [PATCH] drm/msm/dp: skip validity check for DP CTS EDID checksum
@ 2023-09-01 14:20 ` Jani Nikula
  0 siblings, 0 replies; 12+ messages in thread
From: Jani Nikula @ 2023-09-01 14:20 UTC (permalink / raw)
  To: dri-devel
  Cc: jani.nikula, Abhinav Kumar, Dmitry Baryshkov, Kuogee Hsieh,
	Marijn Suijten, Rob Clark, Sean Paul, Stephen Boyd, linux-arm-msm,
	freedreno

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>
---
 drivers/gpu/drm/msm/dp/dp_panel.c | 21 ++-------------------
 1 file 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 42d52510ffd4..86a8e06c7a60 100644
--- a/drivers/gpu/drm/msm/dp/dp_panel.c
+++ b/drivers/gpu/drm/msm/dp/dp_panel.c
@@ -289,26 +289,9 @@ 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)
-- 
2.39.2


^ permalink raw reply related	[flat|nested] 12+ messages in thread

end of thread, other threads:[~2023-10-08 14:01 UTC | newest]

Thread overview: 12+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-09-01 14:20 [PATCH] drm/msm/dp: skip validity check for DP CTS EDID checksum Jani Nikula
2023-09-01 14:20 ` Jani Nikula
2023-09-07 21:46 ` Stephen Boyd
2023-09-07 21:46   ` Stephen Boyd
2023-09-12 12:16   ` Jani Nikula
2023-09-12 12:16     ` Jani Nikula
2023-09-12 16:41     ` [Freedreno] " Abhinav Kumar
2023-09-12 16:41       ` Abhinav Kumar
2023-09-12 17:25       ` Jani Nikula
2023-09-12 17:25         ` Jani Nikula
2023-10-08 14:01 ` Dmitry Baryshkov
2023-10-08 14:01   ` Dmitry Baryshkov

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