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 <ramalinga...@intel.com> --- 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 32static 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
_______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
