On Tue, Oct 12, 2021 at 05:43:21PM +0300, Jani Nikula wrote: > Use the new link training delay helpers, fixing the delays for > 128b/132b. > > For existing 8b/10b functionality, this will cause additional 1-byte > DPCD reads for LTTPR delays instead of using the cached values. It's > just too complicated to combine generic helpers with local caching in a > sensible way. > > Cc: Ville Syrjälä <ville.syrj...@linux.intel.com> > Signed-off-by: Jani Nikula <jani.nik...@intel.com>
I was just pondering if the extra DPCD reads might cause some grief for some compliance test stuff. But I guess if that happens we could just read them all at the very start of link training, or something. Reviewed-by: Ville Syrjälä <ville.syrj...@linux.intel.com> > --- > .../drm/i915/display/intel_dp_link_training.c | 38 +++++++------------ > 1 file changed, 13 insertions(+), 25 deletions(-) > > 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 85676c953e0a..a72f2dc93718 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > @@ -683,15 +683,6 @@ intel_dp_prepare_link_train(struct intel_dp *intel_dp, > return true; > } > > -static void intel_dp_link_training_clock_recovery_delay(struct intel_dp > *intel_dp, > - enum drm_dp_phy dp_phy) > -{ > - if (dp_phy == DP_PHY_DPRX) > - drm_dp_link_train_clock_recovery_delay(&intel_dp->aux, > intel_dp->dpcd); > - else > - drm_dp_lttpr_link_train_clock_recovery_delay(); > -} > - > static bool intel_dp_adjust_request_changed(const struct intel_crtc_state > *crtc_state, > const u8 > old_link_status[DP_LINK_STATUS_SIZE], > const u8 > new_link_status[DP_LINK_STATUS_SIZE]) > @@ -750,6 +741,11 @@ intel_dp_link_training_clock_recovery(struct intel_dp > *intel_dp, > u8 link_status[DP_LINK_STATUS_SIZE]; > bool max_vswing_reached = false; > char phy_name[10]; > + int delay_us; > + > + delay_us = drm_dp_read_clock_recovery_delay(&intel_dp->aux, > + intel_dp->dpcd, dp_phy, > + > intel_dp_is_uhbr(crtc_state)); > > intel_dp_phy_name(dp_phy, phy_name, sizeof(phy_name)); > > @@ -777,7 +773,7 @@ intel_dp_link_training_clock_recovery(struct intel_dp > *intel_dp, > > voltage_tries = 1; > for (cr_tries = 0; cr_tries < max_cr_tries; ++cr_tries) { > - intel_dp_link_training_clock_recovery_delay(intel_dp, dp_phy); > + usleep_range(delay_us, 2 * delay_us); > > if (drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, dp_phy, > link_status) < 0) { > @@ -895,19 +891,6 @@ static u32 intel_dp_training_pattern(struct intel_dp > *intel_dp, > return DP_TRAINING_PATTERN_2; > } > > -static void > -intel_dp_link_training_channel_equalization_delay(struct intel_dp *intel_dp, > - enum drm_dp_phy dp_phy) > -{ > - if (dp_phy == DP_PHY_DPRX) { > - drm_dp_link_train_channel_eq_delay(&intel_dp->aux, > intel_dp->dpcd); > - } else { > - const u8 *phy_caps = intel_dp_lttpr_phy_caps(intel_dp, dp_phy); > - > - drm_dp_lttpr_link_train_channel_eq_delay(&intel_dp->aux, > phy_caps); > - } > -} > - > /* > * Perform the link training channel equalization phase on the given DP PHY > * using one of training pattern 2, 3 or 4 depending on the source and > @@ -925,6 +908,11 @@ intel_dp_link_training_channel_equalization(struct > intel_dp *intel_dp, > u8 link_status[DP_LINK_STATUS_SIZE]; > bool channel_eq = false; > char phy_name[10]; > + int delay_us; > + > + delay_us = drm_dp_read_channel_eq_delay(&intel_dp->aux, > + intel_dp->dpcd, dp_phy, > + intel_dp_is_uhbr(crtc_state)); > > intel_dp_phy_name(dp_phy, phy_name, sizeof(phy_name)); > > @@ -944,8 +932,8 @@ intel_dp_link_training_channel_equalization(struct > intel_dp *intel_dp, > } > > for (tries = 0; tries < 5; tries++) { > - intel_dp_link_training_channel_equalization_delay(intel_dp, > - dp_phy); > + usleep_range(delay_us, 2 * delay_us); > + > if (drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, dp_phy, > link_status) < 0) { > drm_err(&i915->drm, > -- > 2.30.2 -- Ville Syrjälä Intel