If the panel supports FEC, the driver has to set the FEC_READY bit in the dpcd register: FEC_CONFIGURATION.

This has to happen before link training.

v2: s/intel_dp_set_fec_ready/intel_dp_sink_set_fec_ready - change commit message. (Gaurav)

v3: rebased. (r-b Manasi)

v4: Use fec crtc state, before setting FEC_READY bit. (Anusha)

v5: Move to intel_ddi.c - Make the function static (Anusha)

Cc: dri-devel@lists.freedesktop.org Cc: Gaurav K Singh gaurav.k.singh@intel.com Cc: Jani Nikula jani.nikula@linux.intel.com Cc: Ville Syrjala ville.syrjala@linux.intel.com Cc: Manasi Navare manasi.d.navare@intel.com Signed-off-by: Anusha Srivatsa anusha.srivatsa@intel.com --- drivers/gpu/drm/i915/intel_ddi.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c index 1de0a3917d7f..05b6ffeb13be 100644 --- a/drivers/gpu/drm/i915/intel_ddi.c +++ b/drivers/gpu/drm/i915/intel_ddi.c @@ -2889,6 +2889,20 @@ static void intel_ddi_clk_disable(struct intel_encoder *encoder) } }

+static void intel_dp_sink_set_fec_ready(struct intel_dp *intel_dp, + const struct intel_crtc_state *crtc_state, + int state) +{ + int ret; + + if (!crtc_state->fec_enable) + return; + + ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_FEC_CONFIGURATION, state); + if (ret < 0) + DRM_DEBUG_KMS("Failed to get FEC enabled in sink\n"); +} + static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, const struct intel_crtc_state *crtc_state, const struct drm_connector_state *conn_state) @@ -2932,6 +2946,7 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder, intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON); intel_dp_sink_set_decompression_state(intel_dp, crtc_state, DP_DECOMPRESSION_EN); + intel_dp_sink_set_fec_ready(intel_dp, crtc_state, DP_FEC_READY); intel_dp_start_link_train(intel_dp); if (port != PORT_A || INTEL_GEN(dev_priv) >= 9) intel_dp_stop_link_train(intel_dp);