diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index d46cd205241c..2c98335c260c 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -3709,9 +3709,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) { int ret; - intel_dp_lttpr_init(intel_dp); - - if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd)) + if (intel_dp_init_lttpr_and_dprx_caps(intel_dp) < 0) return false; /* 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 c0e25c75c105..f14ac2694183 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c @@ -35,6 +35,11 @@ intel_dp_dump_link_status(struct drm_device *drm, link_status[3], link_status[4], link_status[5]); } +static void intel_dp_reset_lttpr_common_caps(struct intel_dp *intel_dp) +{ + memset(&intel_dp->lttpr_common_caps, 0, sizeof(intel_dp->lttpr_common_caps)); +} + static void intel_dp_reset_lttpr_count(struct intel_dp *intel_dp) { intel_dp->lttpr_common_caps[DP_PHY_REPEATER_CNT - @@ -96,8 +101,7 @@ static bool intel_dp_read_lttpr_common_caps(struct intel_dp *intel_dp) if (drm_dp_read_lttpr_common_caps(&intel_dp->aux, intel_dp->lttpr_common_caps) < 0) { - memset(intel_dp->lttpr_common_caps, 0, - sizeof(intel_dp->lttpr_common_caps)); + intel_dp_reset_lttpr_common_caps(intel_dp); return false; } @@ -119,30 +123,49 @@ intel_dp_set_lttpr_transparent_mode(struct intel_dp *intel_dp, bool enable) } /** - * intel_dp_lttpr_init - detect LTTPRs and init the LTTPR link training mode + * intel_dp_init_lttpr_and_dprx_caps - detect LTTPR and DPRX caps, init the LTTPR link training mode * @intel_dp: Intel DP struct * - * Read the LTTPR common capabilities, switch to non-transparent link training - * mode if any is detected and read the PHY capabilities for all detected - * LTTPRs. In case of an LTTPR detection error or if the number of + * Read the LTTPR common and DPRX capabilities and switch to non-transparent + * link training mode if any is detected and read the PHY capabilities for all + * detected LTTPRs. In case of an LTTPR detection error or if the number of * LTTPRs is more than is supported (8), fall back to the no-LTTPR, * transparent mode link training mode. * * Returns: - * >0 if LTTPRs were detected and the non-transparent LT mode was set + * >0 if LTTPRs were detected and the non-transparent LT mode was set. The + * DPRX capabilities are read out. * 0 if no LTTPRs or more than 8 LTTPRs were detected or in case of a - * detection failure and the transparent LT mode was set + * detection failure and the transparent LT mode was set. The DPRX + * capabilities are read out. + * <0 Reading out the DPRX capabilities failed. */ -int intel_dp_lttpr_init(struct intel_dp *intel_dp) +int intel_dp_init_lttpr_and_dprx_caps(struct intel_dp *intel_dp) { int lttpr_count; bool ret; int i; ret = intel_dp_read_lttpr_common_caps(intel_dp); + + /* The DPTX shall read the DPRX caps after LTTPR detection. */ + if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd)) { + intel_dp_reset_lttpr_common_caps(intel_dp); + return -EIO; + } + if (!ret) return 0; + /* + * The 0xF0000-0xF02FF range is only valid if the DPCD revision is + * at least 1.4. + */ + if (intel_dp->dpcd[DP_DPCD_REV] < 0x14) { + intel_dp_reset_lttpr_common_caps(intel_dp); + return 0; + } + lttpr_count = drm_dp_lttpr_count(intel_dp->lttpr_common_caps); /* * Prevent setting LTTPR transparent mode explicitly if no LTTPRs are @@ -182,7 +205,7 @@ int intel_dp_lttpr_init(struct intel_dp *intel_dp) return lttpr_count; } -EXPORT_SYMBOL(intel_dp_lttpr_init); +EXPORT_SYMBOL(intel_dp_init_lttpr_and_dprx_caps); static u8 dp_voltage_max(u8 preemph) { @@ -817,7 +840,10 @@ void intel_dp_start_link_train(struct intel_dp *intel_dp, * TODO: Reiniting LTTPRs here won't be needed once proper connector * HW state readout is added. */ - int lttpr_count = intel_dp_lttpr_init(intel_dp); + int lttpr_count = intel_dp_init_lttpr_and_dprx_caps(intel_dp); + + if (lttpr_count < 0) + return; if (!intel_dp_link_train_all_phys(intel_dp, crtc_state, lttpr_count)) intel_dp_schedule_fallback_link_training(intel_dp, crtc_state); diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.h b/drivers/gpu/drm/i915/display/intel_dp_link_training.h index 6a1f76bd8c75..9cb7c28027f0 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.h +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.h @@ -11,7 +11,7 @@ struct intel_crtc_state; struct intel_dp; -int intel_dp_lttpr_init(struct intel_dp *intel_dp); +int intel_dp_init_lttpr_and_dprx_caps(struct intel_dp *intel_dp); void intel_dp_get_adjust_train(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state,