[Intel-gfx] [PATCH v2] drm/i915/hdcp: Add additional R0' wait

Sean Paul sean at poorly.run
Wed May 20 13:08:08 UTC 2020

From: Sean Paul <seanpaul at chromium.org>

We're seeing some R0' mismatches in the field, particularly with
repeaters. I'm guessing the (already lenient) 300ms wait time isn't
enough for some setups. So add an additional wait when R0' is

Signed-off-by: Sean Paul <seanpaul at chromium.org>

Changes in v2:
- Actually add the delay in R0` wait (Ram)

Apologies, v1 was generated from a forward port from the CrOS kernel and
patch got confused and put the diff in V' wait instead of R0' wait.

Pay closer attention, Sean.

 drivers/gpu/drm/i915/display/intel_hdcp.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_hdcp.c b/drivers/gpu/drm/i915/display/intel_hdcp.c
index 2cbc4619b4ce..3c2d8c0a6da6 100644
--- a/drivers/gpu/drm/i915/display/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/display/intel_hdcp.c
@@ -743,6 +743,9 @@ static int intel_hdcp_auth(struct intel_connector *connector)
 		if (!wait_for(intel_de_read(dev_priv, HDCP_STATUS(dev_priv, cpu_transcoder, port)) &
+		/* Maybe the sink is lazy, give it some more time */
+		usleep_range(10000, 50000);
 	if (i == tries) {
Sean Paul, Software Engineer, Google / Chromium OS

More information about the Intel-gfx mailing list