In case of UHBR rates, we do not need to explicitly enable FEC by writing to DP_TP_CTL register. For MST use-cases, intel_dp_mst_find_vcpi_slots_for_bpp() takes care of setting fec_enable to false. However, it gets overwritten in intel_dp_dsc_compute_config(). This change keeps fec_enable false across MST and SST use-cases for UHBR rates. While at it, add a comment explaining why we don't enable FEC in eDP v1.5. v2: Correct logic to cater to SST use-cases (Jani) Signed-off-by: Chaitanya Kumar Borah <chaitanya.kumar.borah@xxxxxxxxx> --- drivers/gpu/drm/i915/display/intel_dp.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 49a37b996530..de30eaacd9b4 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -2298,9 +2298,15 @@ int intel_dp_dsc_compute_config(struct intel_dp *intel_dp, &pipe_config->hw.adjusted_mode; int ret; + /* + * Though eDP v1.5 supports FEC with DSC, unlike DP, it is optional. + * Since, FEC is a bandwidth overhead, continue to not enable it for + * eDP. Until, there is a good reason to do so. + */ pipe_config->fec_enable = pipe_config->fec_enable || (!intel_dp_is_edp(intel_dp) && - intel_dp_supports_fec(intel_dp, connector, pipe_config)); + intel_dp_supports_fec(intel_dp, connector, pipe_config) && + !intel_dp_is_uhbr(pipe_config)); if (!intel_dp_supports_dsc(connector, pipe_config)) return -EINVAL; -- 2.25.1
