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Atm, both the legacy (0x202 - 0x205) and > > the ESI (0x200C - 0x200F) link status registers are used. Use always the > > latter ESI version of link status registers. > > > > Signed-off-by: Imre Deak > > --- > > drivers/gpu/drm/i915/display/intel_dp.c | 20 ++++++++++++++++++-- > > 1 file changed, 18 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c > > index 3f911c930a30b..ac7e08f485309 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp.c > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > > @@ -5176,6 +5176,23 @@ intel_dp_handle_hdmi_link_status_change(struct intel_dp *intel_dp) > > } > > } > > > > +static bool > > +intel_dp_read_link_status(struct intel_dp *intel_dp, u8 link_status[DP_LINK_STATUS_SIZE]) > > +{ > > + bool ret; > > + > > + memset(link_status, 0, DP_LINK_STATUS_SIZE); > > + > > + if (intel_dp_mst_active_streams(intel_dp) > 0) > > + ret = drm_dp_dpcd_read_data(&intel_dp->aux, DP_LANE0_1_STATUS_ESI, > > + link_status, DP_LINK_STATUS_SIZE - 2) == 0; > > + else > > + ret = drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, DP_PHY_DPRX, > > + link_status) == 0; > > Please propagate the int instead of having "== 0" at the end of the > assignment. > > I'm increasingly critical of bool returns for success/failure, because > they don't really mix well with 0 for success and negative values for > error. Ok will do that. Both ways are used all around, but I suppose propagating the error code should be the default choice. An exception being adding a new variant of an already existing function with a bool success/failure return type where the new variant should do the same. > > + > > + return ret; > > +} > > + > > static bool > > intel_dp_needs_link_retrain(struct intel_dp *intel_dp) > > { > > @@ -5198,8 +5215,7 @@ intel_dp_needs_link_retrain(struct intel_dp *intel_dp) > > if (intel_dp->link.force_retrain) > > return true; > > > > - if (drm_dp_dpcd_read_phy_link_status(&intel_dp->aux, DP_PHY_DPRX, > > - link_status) < 0) > > + if (!intel_dp_read_link_status(intel_dp, link_status)) > > return false; > > > > /* > > -- > Jani Nikula, Intel