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.

Reviewed-by: Ville Syrjälä <[email protected]>
Signed-off-by: Imre Deak <[email protected]>
---
 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 69a4e9c86d386..778cc33d3c690 100644
--- a/drivers/gpu/drm/i915/display/intel_dp.c
+++ b/drivers/gpu/drm/i915/display/intel_dp.c
@@ -3415,8 +3415,11 @@ 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

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