Re: [PATCH 30/43] drm/i915: Enable and Disable HDCP2.2 port encryption

Chris Wilson
2018-02-14T14:39:00Z

Quoting Ramalingam C (2018-02-14 14:13:45)
> Implements the enable and disable functions for HDCP2.2 encryption
> of the PORT.
>
> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
> ---
> drivers/gpu/drm/i915/intel_hdcp.c | 50 +++++++++++++++++++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/intel_hdcp.c b/drivers/gpu/drm/i915/intel_hdcp.c
> index 0cd637dd3f6b..6a0506cdefd5 100644
> --- a/drivers/gpu/drm/i915/intel_hdcp.c
> +++ b/drivers/gpu/drm/i915/intel_hdcp.c
> @@ -20,6 +20,7 @@
> (enum 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)
> @@ -1336,3 +1337,52 @@ static int hdcp2_authenticate_sink(struct intel_hdcp *hdcp)
>
> return ret;
> }
> +
> +static int hdcp2_enable_encryption(struct intel_hdcp *hdcp)
> +{
> + struct intel_digital_port *intel_dig_port =
> + conn_to_dig_port(hdcp->connector);
> + struct drm_i915_private *dev_priv = to_i915(hdcp->connector->base.dev);
> + enum port port = hdcp->connector->encoder->port;
> + int ret;
> +
> + if (I915_READ(HDCP2_STATUS_DDI(port)) & LINK_ENCRYPTION_STATUS)
> + return 0;
> +
> + if (hdcp->hdcp2_shim->toggle_signalling)
> + hdcp->hdcp2_shim->toggle_signalling(intel_dig_port, true);
> +
> + if (I915_READ(HDCP2_STATUS_DDI(port)) & LINK_AUTH_STATUS) {
> +
> + /* Link is Authenticated. Now set for Encryption */
> + I915_WRITE(HDCP2_CTR_DDI(port),
> + I915_READ(HDCP2_CTR_DDI(port)) |
> + CTL_LINK_ENCRYPTION_REQ);
> + }
> +
> + ret = wait_for(I915_READ(HDCP2_STATUS_DDI(port)) &
> + LINK_ENCRYPTION_STATUS, TIME_FOR_ENCRYPT_STATUS_CHANGE);

Both of these wait_for are intel_wait_for_register. As a rule of thumb
avoid new (and definitely not repeated) use of wait_for().
-Chris