Commit 4bfbec68 authored by Ramalingam C's avatar Ramalingam C Committed by Rodrigo Vivi

drm/i915: Read HDCP R0 thrice in case of mismatch

As per DP spec when R0 mismatch is detected, HDCP source supported
re-read the R0 atleast twice.

And For HDMI and DP minimum wait required for the R0 availability is
100mSec. So this patch changes the wait time to 100mSec but retries
twice with the time interval of 100mSec for each attempt.

This patch is needed for DP HDCP1.4 CTS Test: 1A-06.

v2:
  No Change
v3:
  Comment on R0 retry is moved closer to the code[Seanpaul]
v4:
  Removing unwanted noise introduced in v3.
Signed-off-by: default avatarRamalingam C <ramalingam.c@intel.com>
Reviewed-by: default avatarSean Paul <seanpaul@chromium.org>
Signed-off-by: default avatarRodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1522669822-2508-1-git-send-email-ramalingam.c@intel.com
parent 2a694feb
......@@ -506,6 +506,13 @@ static int intel_hdcp_auth(struct intel_digital_port *intel_dig_port,
*/
wait_remaining_ms_from_jiffies(r0_prime_gen_start, 300);
tries = 3;
/*
* DP HDCP Spec mandates the two more reattempt to read R0, incase
* of R0 mismatch.
*/
for (i = 0; i < tries; i++) {
ri.reg = 0;
ret = shim->read_ri_prime(intel_dig_port, ri.shim);
if (ret)
......@@ -513,8 +520,12 @@ static int intel_hdcp_auth(struct intel_digital_port *intel_dig_port,
I915_WRITE(PORT_HDCP_RPRIME(port), ri.reg);
/* Wait for Ri prime match */
if (wait_for(I915_READ(PORT_HDCP_STATUS(port)) &
(HDCP_STATUS_RI_MATCH | HDCP_STATUS_ENC), 1)) {
if (!wait_for(I915_READ(PORT_HDCP_STATUS(port)) &
(HDCP_STATUS_RI_MATCH | HDCP_STATUS_ENC), 1))
break;
}
if (i == tries) {
DRM_ERROR("Timed out waiting for Ri prime match (%x)\n",
I915_READ(PORT_HDCP_STATUS(port)));
return -ETIMEDOUT;
......
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