drm/amd/display: reuse current context instead of recreating one

[Why]
Currently we discard the current context and recreate it. The current
context is what is applied to the HW so we should be re-using this
rather than creating a new context.

Recreating the context can lead to mismatch between new context and the
current context

For example: gsl groups get changed when we create a new context this
can cause issues in a multi display config (with flip immediate) because
we don't align the existing gsl groups in the new and current context.
If we reuse the current context the gsl group assignment stays the same.

[How]
Instead of discarding the current context, we instead just copy the
current state and add/remove planes and streams.
Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Anson Jacob <Anson.Jacob@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -1936,7 +1936,7 @@ static void dm_gpureset_commit_state(struct dc_state *dc_state,
 		dc_commit_updates_for_stream(
 			dm->dc, bundle->surface_updates,
 			dc_state->stream_status->plane_count,
-			dc_state->streams[k], &bundle->stream_update, dc_state);
+			dc_state->streams[k], &bundle->stream_update);
 	}
 
 cleanup:
@@ -1967,8 +1967,7 @@ static void dm_set_dpms_off(struct dc_link *link)
 
 	stream_update.stream = stream_state;
 	dc_commit_updates_for_stream(stream_state->ctx->dc, NULL, 0,
-				     stream_state, &stream_update,
-				     stream_state->ctx->dc->current_state);
+				     stream_state, &stream_update);
 	mutex_unlock(&adev->dm.dc_lock);
 }
 
@@ -7641,7 +7640,7 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
 				    struct drm_crtc *pcrtc,
 				    bool wait_for_vblank)
 {
-	uint32_t i;
+	int i;
 	uint64_t timestamp_ns;
 	struct drm_plane *plane;
 	struct drm_plane_state *old_plane_state, *new_plane_state;
@@ -7682,7 +7681,7 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
 		amdgpu_dm_commit_cursors(state);
 
 	/* update planes when needed */
-	for_each_oldnew_plane_in_state(state, plane, old_plane_state, new_plane_state, i) {
+	for_each_oldnew_plane_in_state_reverse(state, plane, old_plane_state, new_plane_state, i) {
 		struct drm_crtc *crtc = new_plane_state->crtc;
 		struct drm_crtc_state *new_crtc_state;
 		struct drm_framebuffer *fb = new_plane_state->fb;
@@ -7905,8 +7904,7 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
 						     bundle->surface_updates,
 						     planes_count,
 						     acrtc_state->stream,
-						     &bundle->stream_update,
-						     dc_state);
+						     &bundle->stream_update);
 
 		/**
 		 * Enable or disable the interrupts on the backend.
@@ -8242,13 +8240,13 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 		struct dm_connector_state *dm_new_con_state = to_dm_connector_state(new_con_state);
 		struct dm_connector_state *dm_old_con_state = to_dm_connector_state(old_con_state);
 		struct amdgpu_crtc *acrtc = to_amdgpu_crtc(dm_new_con_state->base.crtc);
-		struct dc_surface_update dummy_updates[MAX_SURFACES];
+		struct dc_surface_update surface_updates[MAX_SURFACES];
 		struct dc_stream_update stream_update;
 		struct dc_info_packet hdr_packet;
 		struct dc_stream_status *status = NULL;
 		bool abm_changed, hdr_changed, scaling_changed;
 
-		memset(&dummy_updates, 0, sizeof(dummy_updates));
+		memset(&surface_updates, 0, sizeof(surface_updates));
 		memset(&stream_update, 0, sizeof(stream_update));
 
 		if (acrtc) {
@@ -8305,16 +8303,15 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 		 * To fix this, DC should permit updating only stream properties.
 		 */
 		for (j = 0; j < status->plane_count; j++)
-			dummy_updates[j].surface = status->plane_states[0];
+			surface_updates[j].surface = status->plane_states[j];
 
 
 		mutex_lock(&dm->dc_lock);
 		dc_commit_updates_for_stream(dm->dc,
-						     dummy_updates,
+						surface_updates,
 						     status->plane_count,
 						     dm_new_crtc_state->stream,
-						     &stream_update,
-						     dc_state);
+						     &stream_update);
 		mutex_unlock(&dm->dc_lock);
 	}
 

drivers/gpu/drm/amd/display/dc/core/dc.c

@@ -2695,8 +2695,7 @@ void dc_commit_updates_for_stream(struct dc *dc,
 		struct dc_surface_update *srf_updates,
 		int surface_count,
 		struct dc_stream_state *stream,
-		struct dc_stream_update *stream_update,
-		struct dc_state *state)
+		struct dc_stream_update *stream_update)
 {
 	const struct dc_stream_status *stream_status;
 	enum surface_update_type update_type;
@@ -2715,6 +2714,12 @@ void dc_commit_updates_for_stream(struct dc *dc,
 
 
 	if (update_type >= UPDATE_TYPE_FULL) {
+		struct dc_plane_state *new_planes[MAX_SURFACES];
+
+		memset(new_planes, 0, sizeof(new_planes));
+
+		for (i = 0; i < surface_count; i++)
+			new_planes[i] = srf_updates[i].surface;
 
 		/* initialize scratch memory for building context */
 		context = dc_create_state(dc);
@@ -2723,15 +2728,21 @@ void dc_commit_updates_for_stream(struct dc *dc,
 			return;
 		}
 
-		dc_resource_state_copy_construct(state, context);
+		dc_resource_state_copy_construct(
+				dc->current_state, context);
 
-		for (i = 0; i < dc->res_pool->pipe_count; i++) {
-			struct pipe_ctx *new_pipe = &context->res_ctx.pipe_ctx[i];
-			struct pipe_ctx *old_pipe = &dc->current_state->res_ctx.pipe_ctx[i];
+		/*remove old surfaces from context */
+		if (!dc_rem_all_planes_for_stream(dc, stream, context)) {
+			DC_ERROR("Failed to remove streams for new validate context!\n");
+			return;
+		}
 
-			if (new_pipe->plane_state && new_pipe->plane_state != old_pipe->plane_state)
-				new_pipe->plane_state->force_full_update = true;
+		/* add surface to context */
+		if (!dc_add_all_planes_for_stream(dc, stream, new_planes, surface_count, context)) {
+			DC_ERROR("Failed to add streams for new validate context!\n");
+			return;
 		}
+
 	}
 
 

drivers/gpu/drm/amd/display/dc/dc_stream.h

@@ -294,8 +294,7 @@ void dc_commit_updates_for_stream(struct dc *dc,
 		struct dc_surface_update *srf_updates,
 		int surface_count,
 		struct dc_stream_state *stream,
-		struct dc_stream_update *stream_update,
-		struct dc_state *state);
+		struct dc_stream_update *stream_update);
 /*
  * Log the current stream state.
  */