HDCP specification says that when bksv is identified as invalid
(not with 20 1s), bksv should be re-read and verified.
This patch adds the above mentioned re-read for bksv.
v2:
Rephrased the commit msg [Seanpaul]
v3:
do-while to for-loop [Seanpaul]
Signed-off-by: Ramalingam C <ramalinga...@intel.com>
---
drivers/gpu/drm/i915/intel_hdcp.c | 19 +++++++++++++++----
1 file changed, 15 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_hdcp.c
b/drivers/gpu/drm/i915/intel_hdcp.c
index cfd13ee8c534..b1047dbf3393 100644
--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -397,7 +397,7 @@ static int intel_hdcp_auth(struct intel_digital_port
*intel_dig_port,
struct drm_i915_private *dev_priv;
enum port port;
unsigned long r0_prime_gen_start;
- int ret, i;
+ int ret, i, tries = 2;
union {
u32 reg[2];
u8 shim[DRM_HDCP_AN_LEN];
@@ -438,11 +438,22 @@ static int intel_hdcp_auth(struct intel_digital_port
*intel_dig_port,
r0_prime_gen_start = jiffies;
memset(&bksv, 0, sizeof(bksv));
- ret = shim->read_bksv(intel_dig_port, bksv.shim);
+
+ /* When bksv is invalid, HDCP spec expects a re-read for bksv */
+ for (i = 0; i < tries; i++) {
+ ret = shim->read_bksv(intel_dig_port, bksv.shim);
+ if (!ret) {
+ if (intel_hdcp_is_ksv_valid(bksv.shim)) {
+ break;
+ } else {
+ DRM_ERROR("Invalid BKSV\n");
+ ret = -ENODEV;
+ }
+ }
+ }
+
if (ret)
return ret;
- else if (!intel_hdcp_is_ksv_valid(bksv.shim))
- return -ENODEV;
I915_WRITE(PORT_HDCP_BKSVLO(port), bksv.reg[0]);
I915_WRITE(PORT_HDCP_BKSVHI(port), bksv.reg[1]);
--
2.7.4
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