From dce5da49f65c718ee5520cf033c664cfac4fd2cf Mon Sep 17 00:00:00 2001 From: Alex Hung Date: Wed, 14 Jan 2026 17:20:31 -0700 Subject: [PATCH] drm/amd/display: Fix writeback on DCN 3.2+ [ Upstream commit 9ef84a307582a92ef055ef0bd3db10fd8ac75960 ] [WHAT] 1. Set no scaling for writeback as they are hardcoded in DCN3.2+. 2. Set no fast plane update for writeback commits. Reviewed-by: Harry Wentland Signed-off-by: Alex Hung Signed-off-by: Wayne Lin Tested-by: Dan Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index b3cf43eb6e08..b527d5764b76 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -10411,10 +10411,10 @@ static void dm_set_writeback(struct amdgpu_display_manager *dm, wb_info->dwb_params.capture_rate = dwb_capture_rate_0; - wb_info->dwb_params.scaler_taps.h_taps = 4; - wb_info->dwb_params.scaler_taps.v_taps = 4; - wb_info->dwb_params.scaler_taps.h_taps_c = 2; - wb_info->dwb_params.scaler_taps.v_taps_c = 2; + wb_info->dwb_params.scaler_taps.h_taps = 1; + wb_info->dwb_params.scaler_taps.v_taps = 1; + wb_info->dwb_params.scaler_taps.h_taps_c = 1; + wb_info->dwb_params.scaler_taps.v_taps_c = 1; wb_info->dwb_params.subsample_position = DWB_INTERSTITIAL_SUBSAMPLING; wb_info->mcif_buf_params.luma_pitch = afb->base.pitches[0]; @@ -11430,6 +11430,8 @@ static bool should_reset_plane(struct drm_atomic_state *state, struct drm_crtc_state *old_crtc_state, *new_crtc_state; struct dm_crtc_state *old_dm_crtc_state, *new_dm_crtc_state; struct amdgpu_device *adev = drm_to_adev(plane->dev); + struct drm_connector_state *new_con_state; + struct drm_connector *connector; int i; /* @@ -11440,6 +11442,15 @@ static bool should_reset_plane(struct drm_atomic_state *state, state->allow_modeset) return true; + /* Check for writeback commit */ + for_each_new_connector_in_state(state, connector, new_con_state, i) { + if (connector->connector_type != DRM_MODE_CONNECTOR_WRITEBACK) + continue; + + if (new_con_state->writeback_job) + return true; + } + if (amdgpu_in_reset(adev) && state->allow_modeset) return true;