[Intel-gfx] [PATCH 3/4] drm/i915: debug log for REPLY_ACK missing

[Ramalingam C]

Adding a debug log when the DP_AUX_NATIVE_REPLY_ACK is missing
for aksv write. This helps to locate the possible non responding
DP HDCP sinks.

Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
---
 drivers/gpu/drm/i915/intel_dp.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 70ae3d57316b..18e3a5a3d873 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -5390,7 +5390,11 @@ int intel_dp_hdcp_write_an_aksv(struct intel_digital_port *intel_dig_port,
 	}
 
 	reply = (rxbuf[0] >> 4) & DP_AUX_NATIVE_REPLY_MASK;
-	return reply == DP_AUX_NATIVE_REPLY_ACK ? 0 : -EIO;
+	ret = reply == DP_AUX_NATIVE_REPLY_ACK ? 0 : -EIO;
+	if (ret)
+		DRM_DEBUG_KMS("Aksv write: DP_AUX_NATIVE_REPLY_ACK missing\n");
+
+	return ret;
 }
 
 static int intel_dp_hdcp_read_bksv(struct intel_digital_port *intel_dig_port,
-- 
2.7.4