drm/amdgpu/display/mst: Fix mst_state->pbn_div and slot count assignments

Looks like I made a pretty big mistake here without noticing: it seems when
I moved the assignments of mst_state->pbn_div I completely missed the fact
that the reason for us calling drm_dp_mst_update_slots() earlier was to
account for the fact that we need to call this function using info from the
root MST connector, instead of just trying to do this from each MST
encoder's atomic check function. Otherwise, we end up filling out all of
DC's link information with zeroes.

So, let's restore that and hopefully fix this DSC regression.

Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2171
Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Fixes: 4d07b0bc4034 ("drm/display/dp_mst: Move all payload info into the atomic state")
Cc: stable@vger.kernel.org # 6.1
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Tested-by: Didier Raboud <odyx@debian.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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 39513a6d2244fab1fd6d8ed8af2925af8e2f9c74..2122c2be269b968c1dda9ca58836edf900b381b9 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -9683,6 +9683,8 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
        struct drm_connector_state *old_con_state, *new_con_state;
        struct drm_crtc *crtc;
        struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+       struct drm_dp_mst_topology_mgr *mgr;
+       struct drm_dp_mst_topology_state *mst_state;
        struct drm_plane *plane;
        struct drm_plane_state *old_plane_state, *new_plane_state;
        enum dc_status status;
@@ -9938,6 +9940,28 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
                lock_and_validation_needed = true;
        }
 
+#if defined(CONFIG_DRM_AMD_DC_DCN)
+       /* set the slot info for each mst_state based on the link encoding format */
+       for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
+               struct amdgpu_dm_connector *aconnector;
+               struct drm_connector *connector;
+               struct drm_connector_list_iter iter;
+               u8 link_coding_cap;
+
+               drm_connector_list_iter_begin(dev, &iter);
+               drm_for_each_connector_iter(connector, &iter) {
+                       if (connector->index == mst_state->mgr->conn_base_id) {
+                               aconnector = to_amdgpu_dm_connector(connector);
+                               link_coding_cap = dc_link_dp_mst_decide_link_encoding_format(aconnector->dc_link);
+                               drm_dp_mst_update_slots(mst_state, link_coding_cap);
+
+                               break;
+                       }
+               }
+               drm_connector_list_iter_end(&iter);
+       }
+#endif
+
        /**
         * Streams and planes are reset when there are changes that affect
         * bandwidth. Anything that affects bandwidth needs to go through

diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
index 5fa9bab95038461a36f140b792b7427d1071007f..e8d14ab0953a7310a08717be6daad712a612b8cd 100644 (file)
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
@@ -927,11 +927,6 @@ static int compute_mst_dsc_configs_for_link(struct drm_atomic_state *state,
        if (IS_ERR(mst_state))
                return PTR_ERR(mst_state);
 
-       mst_state->pbn_div = dm_mst_get_pbn_divider(dc_link);
-#if defined(CONFIG_DRM_AMD_DC_DCN)
-       drm_dp_mst_update_slots(mst_state, dc_link_dp_mst_decide_link_encoding_format(dc_link));
-#endif
-
        /* Set up params */
        for (i = 0; i < dc_state->stream_count; i++) {
                struct dc_dsc_policy dsc_policy = {0};