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* [PATCH v2 1/3] drm/i915/dp: Initialize the source OUI write timestamp always
@ 2024-10-01 12:32 Imre Deak
  2024-10-01 12:32 ` [PATCH v2 2/3] drm/i915/dp: Track source OUI validity explicitly Imre Deak
  2024-10-01 12:32 ` [PATCH v2 3/3] drm/i915/dp: Write the source OUI for non-eDP sinks as well Imre Deak
  0 siblings, 2 replies; 5+ messages in thread
From: Imre Deak @ 2024-10-01 12:32 UTC (permalink / raw)
  To: intel-gfx

If the source OUI DPCD register value matches the expected Intel OUI
value, the write timestamp doesn't get updated leaving it at the 0
initial value if the OUI wasn't written before. This can lead to an
incorrect wait duration in intel_dp_wait_source_oui(), since jiffies is
not inited to 0 in general (on a 32 bit system INITIAL_JIFFIES is set to
5 minutes ahead of wrap-around). Fix this by intializing the write
timestamp in the above case as well.

Signed-off-by: Imre Deak <imre.deak@intel.com>
---
 drivers/gpu/drm/i915/display/intel_dp.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
index 16dc1d26d2a25..b7661529f1927 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -3349,8 +3349,11 @@ intel_edp_init_source_oui(struct intel_dp *intel_dp, bool careful)
 		if (drm_dp_dpcd_read(&intel_dp->aux, DP_SOURCE_OUI, buf, sizeof(buf)) < 0)
 			drm_err(&i915->drm, "Failed to read source OUI\n");
 
-		if (memcmp(oui, buf, sizeof(oui)) == 0)
+		if (memcmp(oui, buf, sizeof(oui)) == 0) {
+			/* Assume the OUI was written now. */
+			intel_dp->last_oui_write = jiffies;
 			return;
+		}
 	}
 
 	if (drm_dp_dpcd_write(&intel_dp->aux, DP_SOURCE_OUI, oui, sizeof(oui)) < 0)
-- 
2.44.2


^ permalink raw reply related	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2024-10-01 13:10 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-10-01 12:32 [PATCH v2 1/3] drm/i915/dp: Initialize the source OUI write timestamp always Imre Deak
2024-10-01 12:32 ` [PATCH v2 2/3] drm/i915/dp: Track source OUI validity explicitly Imre Deak
2024-10-01 13:01   ` Jani Nikula
2024-10-01 13:11     ` Imre Deak
2024-10-01 12:32 ` [PATCH v2 3/3] drm/i915/dp: Write the source OUI for non-eDP sinks as well Imre Deak

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