diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index bacdec5d8f3f0200b77b4e68af38a3d9abb35844..1af97adadde848979db254e2d5fe6dca2bceb467 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3547,7 +3547,8 @@ static bool intel_dp_reset_link_train(struct intel_dp *intel_dp, uint32_t *DP, uint8_t dp_train_pat) { - memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set)); + if (!intel_dp->train_set_valid) + memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set)); intel_dp_set_signal_levels(intel_dp, DP); return intel_dp_set_link_train(intel_dp, DP, dp_train_pat); } @@ -3660,6 +3661,23 @@ intel_dp_start_link_train(struct intel_dp *intel_dp) break; } + /* + * if we used previously trained voltage and pre-emphasis values + * and we don't get clock recovery, reset link training values + */ + if (intel_dp->train_set_valid) { + DRM_DEBUG_KMS("clock recovery not ok, reset"); + /* clear the flag as we are not reusing train set */ + intel_dp->train_set_valid = false; + if (!intel_dp_reset_link_train(intel_dp, &DP, + DP_TRAINING_PATTERN_1 | + DP_LINK_SCRAMBLING_DISABLE)) { + DRM_ERROR("failed to enable link training\n"); + return; + } + continue; + } + /* Check to see if we've tried the max voltage */ for (i = 0; i < intel_dp->lane_count; i++) if ((intel_dp->train_set[i] & DP_TRAIN_MAX_SWING_REACHED) == 0) @@ -3737,6 +3755,7 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp) /* Make sure clock is still ok */ if (!drm_dp_clock_recovery_ok(link_status, intel_dp->lane_count)) { + intel_dp->train_set_valid = false; intel_dp_start_link_train(intel_dp); intel_dp_set_link_train(intel_dp, &DP, training_pattern | @@ -3752,6 +3771,7 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp) /* Try 5 times, then try clock recovery if that fails */ if (tries > 5) { + intel_dp->train_set_valid = false; intel_dp_start_link_train(intel_dp); intel_dp_set_link_train(intel_dp, &DP, training_pattern | @@ -3773,9 +3793,10 @@ intel_dp_complete_link_train(struct intel_dp *intel_dp) intel_dp->DP = DP; - if (channel_eq) + if (channel_eq) { + intel_dp->train_set_valid = is_edp(intel_dp); DRM_DEBUG_KMS("Channel EQ done. DP Training successful\n"); - + } } void intel_dp_stop_link_train(struct intel_dp *intel_dp) diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index ea20edb58528108226e3ba67bcf2e553447e68f3..cf701ed264783932f710e5737cef27878b733a3a 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -736,6 +736,7 @@ struct intel_dp { bool has_aux_irq, int send_bytes, uint32_t aux_clock_divider); + bool train_set_valid; /* Displayport compliance testing */ unsigned long compliance_test_type;