HDCP transmitter is supposed to indicate the HDCP encryption status of the link through enc_en signals in a window of time called "window of opportunity" defined by HDCP HDMI spec.
But on KBL this timing of signalling has an issue. To fix the issue this WA of resetting the signalling is required.
v2: WA is moved into the toggle_signalling [Daniel] v3: Commit msg is rewritten with more information v4: Reviewed-by Daniel.
Signed-off-by: Ramalingam C ramalingam.c@intel.com Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch --- drivers/gpu/drm/i915/intel_hdmi.c | 42 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+)
diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c index 6a3e400f54d7..c2c91e6645a5 100644 --- a/drivers/gpu/drm/i915/intel_hdmi.c +++ b/drivers/gpu/drm/i915/intel_hdmi.c @@ -1083,10 +1083,44 @@ int intel_hdmi_hdcp_read_v_prime_part(struct intel_digital_port *intel_dig_port, return ret; }
+static int kbl_repositioning_enc_en_signal(struct intel_connector *connector) +{ + struct drm_i915_private *dev_priv = to_i915(connector->base.dev); + struct intel_digital_port *intel_dig_port = conn_to_dig_port(connector); + struct drm_crtc *crtc = connector->base.state->crtc; + struct intel_crtc *intel_crtc = container_of(crtc, + struct intel_crtc, base); + u32 scanline; + int ret; + + for (;;) { + scanline = I915_READ(PIPEDSL(intel_crtc->pipe)); + if (scanline > 100 && scanline < 200) + break; + usleep_range(25, 50); + } + + ret = intel_ddi_toggle_hdcp_signalling(&intel_dig_port->base, false); + if (ret) { + DRM_ERROR("Disable HDCP signalling failed (%d)\n", ret); + return ret; + } + ret = intel_ddi_toggle_hdcp_signalling(&intel_dig_port->base, true); + if (ret) { + DRM_ERROR("Enable HDCP signalling failed (%d)\n", ret); + return ret; + } + + return 0; +} + static int intel_hdmi_hdcp_toggle_signalling(struct intel_digital_port *intel_dig_port, bool enable) { + struct intel_hdmi *hdmi = &intel_dig_port->hdmi; + struct intel_connector *connector = hdmi->attached_connector; + struct drm_i915_private *dev_priv = to_i915(connector->base.dev); int ret;
if (!enable) @@ -1098,6 +1132,14 @@ int intel_hdmi_hdcp_toggle_signalling(struct intel_digital_port *intel_dig_port, enable ? "Enable" : "Disable", ret); return ret; } + + /* + * WA: To fix incorrect positioning of the window of + * opportunity and enc_en signalling in KABYLAKE. + */ + if (IS_KABYLAKE(dev_priv) && enable) + return kbl_repositioning_enc_en_signal(connector); + return 0; }