drm/amd/display: Temporarily disable stutter on MPO transition

[Why]
Underflow sometimes occurs during transition into MPO with stutter
enabled.

[How]
When transitioning into MPO, disable stutter. Re-enable stutter within
one frame.
Signed-off-by: George Shen <george.shen@amd.com>
Signed-off-by: Tony Cheng <tony.cheng@amd.com>
Reviewed-by: Eric Yang <eric.yang2@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c

@@ -2932,6 +2932,7 @@ void dcn10_update_pending_status(struct pipe_ctx *pipe_ctx)
 	struct dc_plane_state *plane_state = pipe_ctx->plane_state;
 	struct timing_generator *tg = pipe_ctx->stream_res.tg;
 	bool flip_pending;
+	struct dc *dc = plane_state->ctx->dc;
 
 	if (plane_state == NULL)
 		return;
@@ -2949,6 +2950,19 @@ void dcn10_update_pending_status(struct pipe_ctx *pipe_ctx)
 		plane_state->status.is_right_eye =
 				!tg->funcs->is_stereo_left_eye(pipe_ctx->stream_res.tg);
 	}
+
+	if (dc->hwseq->wa_state.disallow_self_refresh_during_multi_plane_transition_applied) {
+		struct dce_hwseq *hwseq = dc->hwseq;
+		struct timing_generator *tg = dc->res_pool->timing_generators[0];
+		unsigned int cur_frame = tg->funcs->get_frame_count(tg);
+
+		if (cur_frame != hwseq->wa_state.disallow_self_refresh_during_multi_plane_transition_applied_on_frame) {
+			struct hubbub *hubbub = dc->res_pool->hubbub;
+
+			hubbub->funcs->allow_self_refresh_control(hubbub, !dc->debug.disable_stutter);
+			hwseq->wa_state.disallow_self_refresh_during_multi_plane_transition_applied = false;
+		}
+	}
 }
 
 void dcn10_update_dchub(struct dce_hwseq *hws, struct dchub_init_data *dh_data)

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

@@ -1584,6 +1584,7 @@ void dcn20_post_unlock_program_front_end(
 {
 	int i;
 	const unsigned int TIMEOUT_FOR_PIPE_ENABLE_MS = 100;
+	struct dce_hwseq *hwseq = dc->hwseq;
 
 	DC_LOGGER_INIT(dc->ctx->logger);
 
@@ -1611,8 +1612,24 @@ void dcn20_post_unlock_program_front_end(
 	}
 
 	/* WA to apply WM setting*/
-	if (dc->hwseq->wa.DEGVIDCN21)
+	if (hwseq->wa.DEGVIDCN21)
 		dc->res_pool->hubbub->funcs->apply_DEDCN21_147_wa(dc->res_pool->hubbub);
+
+
+	/* WA for stutter underflow during MPO transitions when adding 2nd plane */
+	if (hwseq->wa.disallow_self_refresh_during_multi_plane_transition) {
+
+		if (dc->current_state->stream_status[0].plane_count == 1 &&
+				context->stream_status[0].plane_count > 1) {
+
+			struct timing_generator *tg = dc->res_pool->timing_generators[0];
+
+			dc->res_pool->hubbub->funcs->allow_self_refresh_control(dc->res_pool->hubbub, false);
+
+			hwseq->wa_state.disallow_self_refresh_during_multi_plane_transition_applied = true;
+			hwseq->wa_state.disallow_self_refresh_during_multi_plane_transition_applied_on_frame = tg->funcs->get_frame_count(tg);
+		}
+	}
 }
 
 void dcn20_prepare_bandwidth(

drivers/gpu/drm/amd/display/dc/dcn21/dcn21_hubbub.c

@@ -702,6 +702,7 @@ static const struct hubbub_funcs hubbub21_funcs = {
 	.wm_read_state = hubbub21_wm_read_state,
 	.get_dchub_ref_freq = hubbub2_get_dchub_ref_freq,
 	.program_watermarks = hubbub21_program_watermarks,
+	.allow_self_refresh_control = hubbub1_allow_self_refresh_control,
 	.apply_DEDCN21_147_wa = hubbub21_apply_DEDCN21_147_wa,
 };
 

drivers/gpu/drm/amd/display/dc/dcn21/dcn21_resource.c

@@ -1564,6 +1564,7 @@ static struct dce_hwseq *dcn21_hwseq_create(
 		hws->shifts = &hwseq_shift;
 		hws->masks = &hwseq_mask;
 		hws->wa.DEGVIDCN21 = true;
+		hws->wa.disallow_self_refresh_during_multi_plane_transition = true;
 	}
 	return hws;
 }

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

@@ -40,10 +40,13 @@ struct dce_hwseq_wa {
 	bool false_optc_underflow;
 	bool DEGVIDCN10_254;
 	bool DEGVIDCN21;
+	bool disallow_self_refresh_during_multi_plane_transition;
 };
 
 struct hwseq_wa_state {
 	bool DEGVIDCN10_253_applied;
+	bool disallow_self_refresh_during_multi_plane_transition_applied;
+	unsigned int disallow_self_refresh_during_multi_plane_transition_applied_on_frame;
 };
 
 struct pipe_ctx;