drm/amd/display: Turn on phantom OTG before disabling phantom pipe

[Description]
- Proper phantom pipe disable sequence was missing in
  commit_planes_for_stream
- If disabling phantom pipe, turn on phantom OTG first, and turn
  off the phantom OTG after the plane is disabled
- Also update sequence for enabling / disabling phantom streams
  (apply_ctx_to_hw). When enabling phantom pipes, enable before
  doing front end programming for phantom pipes. If disabling
  phantom pipes, disable after front end programming (i.e. after
  phantom plane disable)
- TODO: Still need to properly handle transition case when a phantom
  pipe is transitioned directly into a real pipe (need to fully disable
  the phantom pipe first)
Acked-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Alvin Lee <Alvin.Lee2@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -3326,6 +3326,7 @@ static void commit_planes_for_stream(struct dc *dc,
 	struct pipe_ctx *top_pipe_to_program = NULL;
 	bool should_lock_all_pipes = (update_type != UPDATE_TYPE_FAST);
 	bool subvp_prev_use = false;
+	bool subvp_curr_use = false;
 
 	// Once we apply the new subvp context to hardware it won't be in the
 	// dc->current_state anymore, so we have to cache it before we apply
@@ -3382,6 +3383,15 @@ static void commit_planes_for_stream(struct dc *dc,
 			break;
 	}
 
+	for (i = 0; i < dc->res_pool->pipe_count; i++) {
+		struct pipe_ctx *pipe = &context->res_ctx.pipe_ctx[i];
+
+		if (pipe->stream && pipe->stream->mall_stream_config.type == SUBVP_PHANTOM) {
+			subvp_curr_use = true;
+			break;
+		}
+	}
+
 	if (stream->test_pattern.type != DP_TEST_PATTERN_VIDEO_MODE) {
 		struct pipe_ctx *mpcc_pipe;
 		struct pipe_ctx *odm_pipe;
@@ -3653,42 +3663,22 @@ static void commit_planes_for_stream(struct dc *dc,
 					top_pipe_to_program->stream_res.tg);
 		}
 
-	/* For phantom pipe OTG enable, it has to be done after any previous pipe
-	 * that was in use has already been programmed at gotten its double buffer
-	 * update for "disable".
-	 */
-	if (update_type != UPDATE_TYPE_FAST) {
-		for (i = 0; i < dc->res_pool->pipe_count; i++) {
-			struct pipe_ctx *pipe = &context->res_ctx.pipe_ctx[i];
-			struct pipe_ctx *old_pipe = &dc->current_state->res_ctx.pipe_ctx[i];
-
-			/* If an active, non-phantom pipe is being transitioned into a phantom
-			 * pipe, wait for the double buffer update to complete first before we do
-			 * ANY phantom pipe programming.
-			 */
-			if (pipe->stream && pipe->stream->mall_stream_config.type == SUBVP_PHANTOM &&
-					old_pipe->stream && old_pipe->stream->mall_stream_config.type != SUBVP_PHANTOM) {
-				old_pipe->stream_res.tg->funcs->wait_for_state(
-						old_pipe->stream_res.tg,
-						CRTC_STATE_VBLANK);
-				old_pipe->stream_res.tg->funcs->wait_for_state(
-						old_pipe->stream_res.tg,
-						CRTC_STATE_VACTIVE);
-			}
+	if (subvp_curr_use) {
+		/* If enabling subvp or transitioning from subvp->subvp, enable the
+		 * phantom streams before we program front end for the phantom pipes.
+		 */
+		if (update_type != UPDATE_TYPE_FAST) {
+			if (dc->hwss.enable_phantom_streams)
+				dc->hwss.enable_phantom_streams(dc, context);
 		}
-		for (i = 0; i < dc->res_pool->pipe_count; i++) {
-			struct pipe_ctx *new_pipe = &context->res_ctx.pipe_ctx[i];
+	}
 
-			if ((new_pipe->stream && new_pipe->stream->mall_stream_config.type == SUBVP_PHANTOM) ||
-					subvp_prev_use) {
-				// If old context or new context has phantom pipes, apply
-				// the phantom timings now. We can't change the phantom
-				// pipe configuration safely without driver acquiring
-				// the DMCUB lock first.
-				dc->hwss.apply_ctx_to_hw(dc, context);
-				break;
-			}
-		}
+	if (subvp_prev_use && !subvp_curr_use) {
+		/* If disabling subvp, disable phantom streams after front end
+		 * programming has completed (we turn on phantom OTG in order
+		 * to complete the plane disable for phantom pipes).
+		 */
+		dc->hwss.apply_ctx_to_hw(dc, context);
 	}
 
 	if (update_type != UPDATE_TYPE_FAST)

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_hwseq.c

@@ -582,6 +582,9 @@ void dcn20_plane_atomic_disable(struct dc *dc, struct pipe_ctx *pipe_ctx)
 	if (pipe_ctx->stream_res.gsl_group != 0)
 		dcn20_setup_gsl_group_as_lock(dc, pipe_ctx, false);
 
+	if (hubp->funcs->hubp_update_mall_sel)
+		hubp->funcs->hubp_update_mall_sel(hubp, 0, false);
+
 	dc->hwss.set_flip_control_gsl(pipe_ctx, false);
 
 	hubp->funcs->hubp_clk_cntl(hubp, false);
@@ -605,6 +608,9 @@ void dcn20_plane_atomic_disable(struct dc *dc, struct pipe_ctx *pipe_ctx)
 
 void dcn20_disable_plane(struct dc *dc, struct pipe_ctx *pipe_ctx)
 {
+	bool is_phantom = pipe_ctx->plane_state && pipe_ctx->plane_state->is_phantom;
+	struct timing_generator *tg = is_phantom ? pipe_ctx->stream_res.tg : NULL;
+
 	DC_LOGGER_INIT(dc->ctx->logger);
 
 	if (!pipe_ctx->plane_res.hubp || pipe_ctx->plane_res.hubp->power_gated)
@@ -612,6 +618,12 @@ void dcn20_disable_plane(struct dc *dc, struct pipe_ctx *pipe_ctx)
 
 	dcn20_plane_atomic_disable(dc, pipe_ctx);
 
+	/* Turn back off the phantom OTG after the phantom plane is fully disabled
+	 */
+	if (is_phantom)
+		if (tg && tg->funcs->disable_phantom_crtc)
+			tg->funcs->disable_phantom_crtc(tg);
+
 	DC_LOG_DC("Power down front end %d\n",
 					pipe_ctx->pipe_idx);
 }
@@ -1803,6 +1815,18 @@ void dcn20_program_front_end_for_ctx(
 		dcn20_detect_pipe_changes(&dc->current_state->res_ctx.pipe_ctx[i],
 				&context->res_ctx.pipe_ctx[i]);
 
+	/* When disabling phantom pipes, turn on phantom OTG first (so we can get double
+	 * buffer updates properly)
+	 */
+	for (i = 0; i < dc->res_pool->pipe_count; i++)
+		if (context->res_ctx.pipe_ctx[i].update_flags.bits.disable
+				&& dc->current_state->res_ctx.pipe_ctx[i].stream->mall_stream_config.type == SUBVP_PHANTOM) {
+			struct timing_generator *tg = dc->current_state->res_ctx.pipe_ctx[i].stream_res.tg;
+
+			if (tg->funcs->enable_crtc)
+				tg->funcs->enable_crtc(tg);
+		}
+
 	/* OTG blank before disabling all front ends */
 	for (i = 0; i < dc->res_pool->pipe_count; i++)
 		if (context->res_ctx.pipe_ctx[i].update_flags.bits.disable

drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c

@@ -1451,3 +1451,39 @@ void dcn32_update_dsc_pg(struct dc *dc,
 		}
 	}
 }
+
+void dcn32_enable_phantom_streams(struct dc *dc, struct dc_state *context)
+{
+	unsigned int i;
+
+	for (i = 0; i < dc->res_pool->pipe_count; i++) {
+		struct pipe_ctx *pipe = &context->res_ctx.pipe_ctx[i];
+		struct pipe_ctx *old_pipe = &dc->current_state->res_ctx.pipe_ctx[i];
+
+		/* If an active, non-phantom pipe is being transitioned into a phantom
+		 * pipe, wait for the double buffer update to complete first before we do
+		 * ANY phantom pipe programming.
+		 */
+		if (pipe->stream && pipe->stream->mall_stream_config.type == SUBVP_PHANTOM &&
+				old_pipe->stream && old_pipe->stream->mall_stream_config.type != SUBVP_PHANTOM) {
+			old_pipe->stream_res.tg->funcs->wait_for_state(
+					old_pipe->stream_res.tg,
+					CRTC_STATE_VBLANK);
+			old_pipe->stream_res.tg->funcs->wait_for_state(
+					old_pipe->stream_res.tg,
+					CRTC_STATE_VACTIVE);
+		}
+	}
+	for (i = 0; i < dc->res_pool->pipe_count; i++) {
+		struct pipe_ctx *new_pipe = &context->res_ctx.pipe_ctx[i];
+
+		if (new_pipe->stream && new_pipe->stream->mall_stream_config.type == SUBVP_PHANTOM) {
+			// If old context or new context has phantom pipes, apply
+			// the phantom timings now. We can't change the phantom
+			// pipe configuration safely without driver acquiring
+			// the DMCUB lock first.
+			dc->hwss.apply_ctx_to_hw(dc, context);
+			break;
+		}
+	}
+}

drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.h

@@ -102,4 +102,6 @@ void dcn32_update_dsc_pg(struct dc *dc,
 		struct dc_state *context,
 		bool safe_to_disable);
 
+void dcn32_enable_phantom_streams(struct dc *dc, struct dc_state *context);
+
 #endif /* __DC_HWSS_DCN32_H__ */

drivers/gpu/drm/amd/display/dc/dcn32/dcn32_init.c

@@ -106,6 +106,7 @@ static const struct hw_sequencer_funcs dcn32_funcs = {
 	.set_disp_pattern_generator = dcn30_set_disp_pattern_generator,
 	.get_dcc_en_bits = dcn10_get_dcc_en_bits,
 	.commit_subvp_config = dcn32_commit_subvp_config,
+	.enable_phantom_streams = dcn32_enable_phantom_streams,
 	.subvp_pipe_control_lock = dcn32_subvp_pipe_control_lock,
 	.update_visual_confirm_color = dcn20_update_visual_confirm_color,
 	.update_phantom_vp_position = dcn32_update_phantom_vp_position,

drivers/gpu/drm/amd/display/dc/inc/hw_sequencer.h

@@ -266,6 +266,7 @@ struct hw_sequencer_funcs {
 	void (*apply_update_flags_for_phantom)(struct pipe_ctx *phantom_pipe);
 
 	void (*commit_subvp_config)(struct dc *dc, struct dc_state *context);
+	void (*enable_phantom_streams)(struct dc *dc, struct dc_state *context);
 	void (*subvp_pipe_control_lock)(struct dc *dc,
 			struct dc_state *context,
 			bool lock,