Instead of direct calls of the link training functions, use a modeset commit to retrain a DP link in SST mode, similarly to how this is done in DP-MST mode. Originally the current way was chosen presumedly, because there wasn't a well-established way in place for the driver to do an internal (vs. userspace/kernel client) commit. Since then such internal commits became a common place (initial-, HDMI/TC link reset commit), so there is no reason to handle the DP-SST link-retraining case differently. At the end of the current sequence the HW reported a FIFO underrun - without other issues visible to users - because during retraining the link's encoder/port was disabled/re-enabled without also disabling/re-enabling the corresponding pipe/transcoder (as required by the spec); the corresponding underrun error message was suppressed as a known issue. Based on Ankit's test on DG2 the underrun error was still reported as it got detected with some (vblank) delay wrt. other platforms. Switching to a modeset commit resolves these underrun related issues. Cc: Ankit Nautiyal <ankit.k.nautiyal@xxxxxxxxx> Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx> --- drivers/gpu/drm/i915/display/intel_dp.c | 67 ++++--------------------- 1 file changed, 9 insertions(+), 58 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index d4b1b18453dca..f83128ac60756 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -5242,8 +5242,6 @@ static int intel_dp_retrain_link(struct intel_encoder *encoder, { struct drm_i915_private *dev_priv = to_i915(encoder->base.dev); struct intel_dp *intel_dp = enc_to_intel_dp(encoder); - struct intel_crtc *crtc; - bool mst_output = false; u8 pipe_mask; int ret; @@ -5272,64 +5270,17 @@ static int intel_dp_retrain_link(struct intel_encoder *encoder, encoder->base.base.id, encoder->base.name, str_yes_no(intel_dp->link.force_retrain)); - for_each_intel_crtc_in_pipe_mask(&dev_priv->drm, crtc, pipe_mask) { - const struct intel_crtc_state *crtc_state = - to_intel_crtc_state(crtc->base.state); + ret = intel_modeset_commit_pipes(dev_priv, pipe_mask, ctx); + if (ret == -EDEADLK) + return ret; - if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP_MST)) { - mst_output = true; - break; - } + intel_dp->link.force_retrain = false; - /* Suppress underruns caused by re-training */ - intel_set_cpu_fifo_underrun_reporting(dev_priv, crtc->pipe, false); - if (crtc_state->has_pch_encoder) - intel_set_pch_fifo_underrun_reporting(dev_priv, - intel_crtc_pch_transcoder(crtc), false); - } - - /* TODO: use a modeset for SST as well. */ - if (mst_output) { - ret = intel_modeset_commit_pipes(dev_priv, pipe_mask, ctx); - - if (ret && ret != -EDEADLK) - drm_dbg_kms(&dev_priv->drm, - "[ENCODER:%d:%s] link retraining failed: %pe\n", - encoder->base.base.id, encoder->base.name, - ERR_PTR(ret)); - - goto out; - } - - for_each_intel_crtc_in_pipe_mask(&dev_priv->drm, crtc, pipe_mask) { - const struct intel_crtc_state *crtc_state = - to_intel_crtc_state(crtc->base.state); - - intel_dp->link_trained = false; - - intel_dp_check_frl_training(intel_dp); - intel_dp_pcon_dsc_configure(intel_dp, crtc_state); - intel_dp_start_link_train(NULL, intel_dp, crtc_state); - intel_dp_stop_link_train(intel_dp, crtc_state); - break; - } - - for_each_intel_crtc_in_pipe_mask(&dev_priv->drm, crtc, pipe_mask) { - const struct intel_crtc_state *crtc_state = - to_intel_crtc_state(crtc->base.state); - - /* Keep underrun reporting disabled until things are stable */ - intel_crtc_wait_for_next_vblank(crtc); - - intel_set_cpu_fifo_underrun_reporting(dev_priv, crtc->pipe, true); - if (crtc_state->has_pch_encoder) - intel_set_pch_fifo_underrun_reporting(dev_priv, - intel_crtc_pch_transcoder(crtc), true); - } - -out: - if (ret != -EDEADLK) - intel_dp->link.force_retrain = false; + if (ret) + drm_dbg_kms(&dev_priv->drm, + "[ENCODER:%d:%s] link retraining failed: %pe\n", + encoder->base.base.id, encoder->base.name, + ERR_PTR(ret)); return ret; } -- 2.44.2