On Thursday 31 May 2018 12:39 PM, Daniel Vetter wrote:
On Mon, May 21, 2018 at 06:23:44PM +0530, Ramalingam C wrote:
Implements the enable and disable functions for HDCP2.2 encryption
of the PORT.
v2:
intel_wait_for_register is used instead of wait_for. [Chris Wilson]
v3:
No Changes.
v4:
Debug msg is added for timeout at Disable of Encryption [Uma]
%s/HDCP2_CTL/HDCP2_CTL
Signed-off-by: Ramalingam C <ramalingam.c@xxxxxxxxx>
---
drivers/gpu/drm/i915/intel_hdcp.c | 57 +++++++++++++++++++++++++++++++++++++++
1 file changed, 57 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
index bd0bfcfd5b8f..0386a67c3e32 100644
--- a/drivers/gpu/drm/i915/intel_hdcp.c
+++ b/drivers/gpu/drm/i915/intel_hdcp.c
@@ -19,6 +19,7 @@
(enum hdcp_physical_port) (port))
#define KEY_LOAD_TRIES 5
#define HDCP2_LC_RETRY_CNT 3
+#define TIME_FOR_ENCRYPT_STATUS_CHANGE 32
static int intel_hdcp_poll_ksv_fifo(struct intel_digital_port *intel_dig_port,
const struct intel_hdcp_shim *shim)
@@ -1397,3 +1398,59 @@ static int hdcp2_authenticate_sink(struct intel_connector *connector)
return ret;
}
+
+static int hdcp2_enable_encryption(struct intel_connector *connector)
+{
+ struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+ struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+ struct intel_hdcp *hdcp = &connector->hdcp;
+ enum port port = connector->encoder->port;
+ int ret;
+
+ if (I915_READ(HDCP2_STATUS_DDI(port)) & LINK_ENCRYPTION_STATUS)
+ return 0;
Relying on hw status for state decisions is in my experience bad - it
papers over bugs in our state handling. We should know what the expected
state of the hardware is.
If you want to write a bit more robust code, then keep these checks, but
wrap them in a WARN_ON. That way we'll know if there's a regression in the
code (e.g. unbalanced enable/disable) right away, instead of these checks
silently papering over them.
+
+ if (hdcp->hdcp_shim->toggle_signalling)
+ hdcp->hdcp_shim->toggle_signalling(intel_dig_port, true);
+
+ if (I915_READ(HDCP2_STATUS_DDI(port)) & LINK_AUTH_STATUS) {
Same for this check here. In general control flow that depends upon
register values which can change at runtime is very suspect from a design
robustness point of view.
Sure. I will move these HW status check into the WARN_ONs.
-Ram.
-Daniel
+
+ /* Link is Authenticated. Now set for Encryption */
+ I915_WRITE(HDCP2_CTL_DDI(port),
+ I915_READ(HDCP2_CTL_DDI(port)) |
+ CTL_LINK_ENCRYPTION_REQ);
+ }
+
+ ret = intel_wait_for_register(dev_priv, HDCP2_STATUS_DDI(port),
+ LINK_ENCRYPTION_STATUS,
+ LINK_ENCRYPTION_STATUS,
+ TIME_FOR_ENCRYPT_STATUS_CHANGE);
+
+ return ret;
+}
+
+static int hdcp2_disable_encryption(struct intel_connector *connector)
+{
+ struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector);
+ struct drm_i915_private *dev_priv = to_i915(connector->base.dev);
+ struct intel_hdcp *hdcp = &connector->hdcp;
+ enum port port = connector->encoder->port;
+ int ret;
+
+ if (!(I915_READ(HDCP2_STATUS_DDI(port)) & LINK_ENCRYPTION_STATUS))
+ return 0;
+
+ I915_WRITE(HDCP2_CTL_DDI(port),
+ I915_READ(HDCP2_CTL_DDI(port)) & ~CTL_LINK_ENCRYPTION_REQ);
+
+ ret = intel_wait_for_register(dev_priv, HDCP2_STATUS_DDI(port),
+ LINK_ENCRYPTION_STATUS, 0x0,
+ TIME_FOR_ENCRYPT_STATUS_CHANGE);
+ if (ret == -ETIMEDOUT)
+ DRM_DEBUG_KMS("Disable Encryption Timedout");
+
+ if (hdcp->hdcp_shim->toggle_signalling)
+ hdcp->hdcp_shim->toggle_signalling(intel_dig_port, false);
+
+ return ret;
+}
--
2.7.4
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