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drm/i915: Read Vprime thrice incase of mismatch

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In case of V prime mismatch, DP HDCP spec mandates the re-read of
Vprime atleast twice.

This patch needed for DP HDCP1.4 CTS Test: 1B-05.

v2:
  Moved the V' validation into a function for retry. [Sean Paul]
v3:
  Removed Inline keyword and DRM_DEBUG_KMS are used [Sean Paul]

Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1522663834-24482-3-git-send-email-ramalingam.c@intel.com
This commit is contained in:
Ramalingam C 2018-04-02 15:40:32 +05:30 committed by Rodrigo Vivi
parent 4bfbec6896
commit 41baafae29
1 changed files with 70 additions and 42 deletions
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112
drivers/gpu/drm/i915/intel_hdcp.c
View File

@ -142,53 +142,17 @@ bool intel_hdcp_is_ksv_valid(u8 *ksv)
return true;
}
/* Implements Part 2 of the HDCP authorization procedure */
static
int intel_hdcp_auth_downstream(struct intel_digital_port *intel_dig_port,
const struct intel_hdcp_shim *shim)
int intel_hdcp_validate_v_prime(struct intel_digital_port *intel_dig_port,
const struct intel_hdcp_shim *shim,
u8 *ksv_fifo, u8 num_downstream, u8 *bstatus)
{
struct drm_i915_private *dev_priv;
u32 vprime, sha_text, sha_leftovers, rep_ctl;
u8 bstatus[2], num_downstream, *ksv_fifo;
int ret, i, j, sha_idx;
dev_priv = intel_dig_port->base.base.dev->dev_private;
ret = intel_hdcp_poll_ksv_fifo(intel_dig_port, shim);
if (ret) {
DRM_ERROR("KSV list failed to become ready (%d)\n", ret);
return ret;
}
ret = shim->read_bstatus(intel_dig_port, bstatus);
if (ret)
return ret;
if (DRM_HDCP_MAX_DEVICE_EXCEEDED(bstatus[0]) ||
DRM_HDCP_MAX_CASCADE_EXCEEDED(bstatus[1])) {
DRM_ERROR("Max Topology Limit Exceeded\n");
return -EPERM;
}
/*
* When repeater reports 0 device count, HDCP1.4 spec allows disabling
* the HDCP encryption. That implies that repeater can't have its own
* display. As there is no consumption of encrypted content in the
* repeater with 0 downstream devices, we are failing the
* authentication.
*/
num_downstream = DRM_HDCP_NUM_DOWNSTREAM(bstatus[0]);
if (num_downstream == 0)
return -EINVAL;
ksv_fifo = kzalloc(num_downstream * DRM_HDCP_KSV_LEN, GFP_KERNEL);
if (!ksv_fifo)
return -ENOMEM;
ret = shim->read_ksv_fifo(intel_dig_port, num_downstream, ksv_fifo);
if (ret)
return ret;
/* Process V' values from the receiver */
for (i = 0; i < DRM_HDCP_V_PRIME_NUM_PARTS; i++) {
ret = shim->read_v_prime_part(intel_dig_port, i, &vprime);
@ -353,7 +317,8 @@ int intel_hdcp_auth_downstream(struct intel_digital_port *intel_dig_port,
return ret;
sha_idx += sizeof(sha_text);
} else {
DRM_ERROR("Invalid number of leftovers %d\n", sha_leftovers);
DRM_DEBUG_KMS("Invalid number of leftovers %d\n",
sha_leftovers);
return -EINVAL;
}
@ -381,14 +346,77 @@ int intel_hdcp_auth_downstream(struct intel_digital_port *intel_dig_port,
if (intel_wait_for_register(dev_priv, HDCP_REP_CTL,
HDCP_SHA1_COMPLETE,
HDCP_SHA1_COMPLETE, 1)) {
DRM_ERROR("Timed out waiting for SHA1 complete\n");
DRM_DEBUG_KMS("Timed out waiting for SHA1 complete\n");
return -ETIMEDOUT;
}
if (!(I915_READ(HDCP_REP_CTL) & HDCP_SHA1_V_MATCH)) {
DRM_ERROR("SHA-1 mismatch, HDCP failed\n");
DRM_DEBUG_KMS("SHA-1 mismatch, HDCP failed\n");
return -ENXIO;
}
return 0;
}
/* Implements Part 2 of the HDCP authorization procedure */
static
int intel_hdcp_auth_downstream(struct intel_digital_port *intel_dig_port,
const struct intel_hdcp_shim *shim)
{
u8 bstatus[2], num_downstream, *ksv_fifo;
int ret, i, tries = 3;
ret = intel_hdcp_poll_ksv_fifo(intel_dig_port, shim);
if (ret) {
DRM_ERROR("KSV list failed to become ready (%d)\n", ret);
return ret;
}
ret = shim->read_bstatus(intel_dig_port, bstatus);
if (ret)
return ret;
if (DRM_HDCP_MAX_DEVICE_EXCEEDED(bstatus[0]) ||
DRM_HDCP_MAX_CASCADE_EXCEEDED(bstatus[1])) {
DRM_ERROR("Max Topology Limit Exceeded\n");
return -EPERM;
}
/*
* When repeater reports 0 device count, HDCP1.4 spec allows disabling
* the HDCP encryption. That implies that repeater can't have its own
* display. As there is no consumption of encrypted content in the
* repeater with 0 downstream devices, we are failing the
* authentication.
*/
num_downstream = DRM_HDCP_NUM_DOWNSTREAM(bstatus[0]);
if (num_downstream == 0)
return -EINVAL;
ksv_fifo = kzalloc(num_downstream * DRM_HDCP_KSV_LEN, GFP_KERNEL);
if (!ksv_fifo)
return -ENOMEM;
ret = shim->read_ksv_fifo(intel_dig_port, num_downstream, ksv_fifo);
if (ret)
return ret;
/*
* When V prime mismatches, DP Spec mandates re-read of
* V prime atleast twice.
*/
for (i = 0; i < tries; i++) {
ret = intel_hdcp_validate_v_prime(intel_dig_port, shim,
ksv_fifo, num_downstream,
bstatus);
if (!ret)
break;
}
if (i == tries) {
DRM_ERROR("V Prime validation failed.(%d)\n", ret);
return ret;
}
DRM_DEBUG_KMS("HDCP is enabled (%d downstream devices)\n",
num_downstream);
return 0;