diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index e7233dfa17948..d6ee11525dd9b 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3954,6 +3954,9 @@ static void intel_dp_get_dsc_sink_cap(struct intel_dp *intel_dp) */ memset(intel_dp->dsc_dpcd, 0, sizeof(intel_dp->dsc_dpcd)); + /* Clear fec_capable to avoid using stale values */ + intel_dp->fec_capable = 0; + /* Cache the DSC DPCD if eDP or DP rev >= 1.4 */ if (intel_dp->dpcd[DP_DPCD_REV] >= 0x14 || intel_dp->edp_dpcd[0] >= DP_EDP_14) { @@ -3966,6 +3969,15 @@ static void intel_dp_get_dsc_sink_cap(struct intel_dp *intel_dp) DRM_DEBUG_KMS("DSC DPCD: %*ph\n", (int)sizeof(intel_dp->dsc_dpcd), intel_dp->dsc_dpcd); + /* FEC is supported only on DP 1.4 */ + if (!intel_dp_is_edp(intel_dp)) { + if (drm_dp_dpcd_readb(&intel_dp->aux, DP_FEC_CAPABILITY, + &intel_dp->fec_capable) < 0) + DRM_ERROR("Failed to read FEC DPCD register\n"); + + DRM_DEBUG_KMS("FEC CAPABILITY: %x\n", + intel_dp->fec_capable); + } } } diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 191c26e17f2d0..3bebc1c311578 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -1114,6 +1114,7 @@ struct intel_dp { uint8_t downstream_ports[DP_MAX_DOWNSTREAM_PORTS]; uint8_t edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE]; u8 dsc_dpcd[DP_DSC_RECEIVER_CAP_SIZE]; + u8 fec_capable; /* source rates */ int num_source_rates; const int *source_rates;