| Message ID | 20230207052657.2917314-3-arun.r.murthy@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [PATCHv2,1/2] drm: Add SDP Error Detection Configuration Register | expand |
On Tue, 07 Feb 2023, Arun R Murthy <arun.r.murthy@intel.com> 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()...? BR, Jani. > > Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com> > --- > .../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 */ > }
On Tue, 14 Feb 2023, Jani Nikula <jani.nikula@intel.com> wrote: > On Tue, 07 Feb 2023, Arun R Murthy <arun.r.murthy@intel.com> 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@intel.com> >> --- >> .../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 */ >> }
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 */ }
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> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com> --- .../gpu/drm/i915/display/intel_dp_link_training.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)