On Tue, 14 Feb 2023, Jani Nikula <jani.nikula@xxxxxxxxx> wrote: > On Tue, 07 Feb 2023, Arun R Murthy <arun.r.murthy@xxxxxxxxx> wrote: >> Enable SDP error detection configuration, this will set CRC16 in >> 128b/132b link layer. >> For Display version 13 a hardware bit31 in register VIDEO_DIP_CTL is >> added to enable/disable SDP CRC applicable for DP2.0 only, but the >> default value of this bit will enable CRC16 in 128b/132b hence >> skipping this write. >> Corrective actions on SDP corruption is yet to be defined. >> >> v2: Moved the CRC enable to link training init(Jani N) >> v3: Moved crc enable to ddi pre enable <Jani N> > > It's still in intel_dp_start_link_train()...? Also, please post new versions as new threads instead of in-reply-to. I don't think patchwork/CI picked this up at all, for example. BR, Jani > > BR, > Jani. > > >> >> Signed-off-by: Arun R Murthy <arun.r.murthy@xxxxxxxxx> >> --- >> .../gpu/drm/i915/display/intel_dp_link_training.c | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c >> index 3d3efcf02011..7064e465423b 100644 >> --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c >> +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c >> @@ -1453,4 +1453,16 @@ void intel_dp_start_link_train(struct intel_dp *intel_dp, >> >> if (!passed) >> intel_dp_schedule_fallback_link_training(intel_dp, crtc_state); >> + >> + /* DP v2.0 SCR on SDP CRC16 for 128b/132b Link Layer */ >> + if (intel_dp_is_uhbr(crtc_state) && passed) >> + drm_dp_dpcd_writeb(&intel_dp->aux, >> + DP_SDP_ERROR_DETECTION_CONFIGURATION, >> + DP_SDP_CRC16_128B132B_EN); >> + /* >> + * VIDEO_DIP_CTL register bit 31 should be set to '0' to not >> + * disable SDP CRC. This is applicable for Display version 13. >> + * Default value of bit 31 is '0' hence discarding the write >> + */ >> + /* TODO: Corrective actions on SDP corruption yet to be defined */ >> } -- Jani Nikula, Intel Open Source Graphics Center
