From 16fef33fdb1e2269c20697d9b61ae8022bc92665 Mon Sep 17 00:00:00 2001 From: Imre Deak Date: Mon, 24 Feb 2025 11:32:42 +0200 Subject: [PATCH] drm/i915/dp_mst: Fix encoder HW state readout for UHBR MST The encoder HW/SW state verification should use a SW state which stays unchanged while the encoder/output is active. The intel_dp::is_mst flag used during state computation to choose between the DP SST/MST modes can change while the output is active, if the sink gets disconnected or the MST topology is removed for another reason. A subsequent state verification using intel_dp::is_mst leads then to a mismatch if the output is disabled/re-enabled without recomputing its state. Use the encoder's active MST link count instead, which will be always non-zero for an active MST output and will be zero for SST. Fixes: 35d2e4b75649 ("drm/i915/ddi: start distinguishing 128b/132b SST and MST at state readout") Fixes: 40d489fac0e8 ("drm/i915/ddi: handle 128b/132b SST in intel_ddi_read_func_ctl()") Cc: Jani Nikula Reviewed-by: Jani Nikula Signed-off-by: Imre Deak Link: https://patchwork.freedesktop.org/patch/msgid/20250224093242.1859583-1-imre.deak@intel.com (cherry picked from commit 0159e311772af9d6598aafe072c020687720f1d7) Signed-off-by: Rodrigo Vivi --- drivers/gpu/drm/i915/display/intel_ddi.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c index 18c66992aa1d..ff2cf3daa7a2 100644 --- a/drivers/gpu/drm/i915/display/intel_ddi.c +++ b/drivers/gpu/drm/i915/display/intel_ddi.c @@ -866,7 +866,7 @@ static void intel_ddi_get_encoder_pipes(struct intel_encoder *encoder, encoder->base.base.id, encoder->base.name); if (!mst_pipe_mask && dp128b132b_pipe_mask) { - struct intel_dp *intel_dp = enc_to_intel_dp(encoder); + struct intel_digital_port *dig_port = enc_to_dig_port(encoder); /* * If we don't have 8b/10b MST, but have more than one @@ -878,7 +878,8 @@ static void intel_ddi_get_encoder_pipes(struct intel_encoder *encoder, * we don't expect MST to have been enabled at that point, and * can assume it's SST. */ - if (hweight8(dp128b132b_pipe_mask) > 1 || intel_dp->is_mst) + if (hweight8(dp128b132b_pipe_mask) > 1 || + intel_dp_mst_encoder_active_links(dig_port)) mst_pipe_mask = dp128b132b_pipe_mask; } @@ -4151,13 +4152,13 @@ static void intel_ddi_read_func_ctl(struct intel_encoder *encoder, } else if (ddi_mode == TRANS_DDI_MODE_SELECT_DP_MST) { intel_ddi_read_func_ctl_dp_mst(encoder, pipe_config, ddi_func_ctl); } else if (ddi_mode == TRANS_DDI_MODE_SELECT_FDI_OR_128B132B && HAS_DP20(display)) { - struct intel_dp *intel_dp = enc_to_intel_dp(encoder); + struct intel_digital_port *dig_port = enc_to_dig_port(encoder); /* * If this is true, we know we're being called from mst stream * encoder's ->get_config(). */ - if (intel_dp->is_mst) + if (intel_dp_mst_encoder_active_links(dig_port)) intel_ddi_read_func_ctl_dp_mst(encoder, pipe_config, ddi_func_ctl); else intel_ddi_read_func_ctl_dp_sst(encoder, pipe_config, ddi_func_ctl);