> Subject: [PATCH v3 07/10] drm/i915/alpm: Program lttpr count for DP 2.1 > alpm
*LTTPR *ALPM > > Issue a aux write transaction to dpcd 0xf000a with total number of lttpr *DPCD Write the name of the register rather than the address > before link traning. * training > > Cc: Jouni Högander <[email protected]> > Signed-off-by: Animesh Manna <[email protected]> > --- > .../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 aad5fe14962f..cf25fd51f452 100644 > --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c > +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c > @@ -1624,6 +1624,16 @@ intel_dp_128b132b_link_train(struct intel_dp > *intel_dp, > return passed; > } > > +static void intel_dp_update_lttpr_count(struct intel_dp *intel_dp, > + int lttpr_count) > +{ > + if (!intel_dp_is_edp(intel_dp) || > + intel_dp->lttpr_common_caps[0] <= 0x20) Why what is 0x20 avoid magic numbers without proper explanation Regards, Suraj Kandpal > + return; > + > + drm_dp_dpcd_writeb(&intel_dp->aux, DP_TOTAL_LTTPR_CNT, > lttpr_count); } > + > /** > * intel_dp_start_link_train - start link training > * @state: Atomic state > @@ -1660,6 +1670,8 @@ void intel_dp_start_link_train(struct > intel_atomic_state *state, > > intel_dp_prepare_link_train(intel_dp, crtc_state); > > + intel_dp_update_lttpr_count(intel_dp, lttpr_count); > + > if (intel_dp_is_uhbr(crtc_state)) > passed = intel_dp_128b132b_link_train(intel_dp, crtc_state, > lttpr_count); > else > -- > 2.29.0
