Commit 9a902a90 authored by Alvin Lee's avatar Alvin Lee Committed by Alex Deucher
Browse files

drm/amd/display: Force p-state disallow if leaving no plane config 



[Description]
- When we're in a no plane config, DCN is always asserting
  P-State allow
- This creates a scenario where the P-State blackout can start
  just as VUPDATE takes place and transitions the DCN config to
  a one where one or more HUBP's are active which can result in
  underflow
- To fix this issue, force p-state disallow and unforce after
  the transition from no planes case -> one or more planes active

Reviewed-by: default avatarSamson Tam <samson.tam@amd.com>
Acked-by: default avatarAurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: default avatarAlvin Lee <alvin.lee2@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent dd4e4bb2

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

+20 −0
Original line number Diff line number Diff line
@@ -1877,6 +1877,8 @@ void dcn20_program_front_end_for_ctx( 
	int i;

	struct dce_hwseq *hws = dc->hwseq;

	DC_LOGGER_INIT(dc->ctx->logger);

	unsigned int prev_hubp_count = 0;

	unsigned int hubp_count = 0;



	if (resource_is_pipe_topology_changed(dc->current_state, context))

		resource_log_pipe_topology_update(dc, context);
@@ -1894,6 +1896,20 @@ void dcn20_program_front_end_for_ctx( 
		}

	}



	for (i = 0; i < dc->res_pool->pipe_count; i++) {

		if (dc->current_state->res_ctx.pipe_ctx[i].plane_state)

			prev_hubp_count++;

		if (context->res_ctx.pipe_ctx[i].plane_state)

			hubp_count++;

	}



	if (prev_hubp_count == 0 && hubp_count > 0) {

		if (dc->res_pool->hubbub->funcs->force_pstate_change_control)

			dc->res_pool->hubbub->funcs->force_pstate_change_control(

					dc->res_pool->hubbub, true, false);

		udelay(500);

	}



	/* Set pipe update flags and lock pipes */

	for (i = 0; i < dc->res_pool->pipe_count; i++)

		dcn20_detect_pipe_changes(&dc->current_state->res_ctx.pipe_ctx[i],
@@ -2039,6 +2055,10 @@ void dcn20_post_unlock_program_front_end( 
		}

	}



	if (dc->res_pool->hubbub->funcs->force_pstate_change_control)

		dc->res_pool->hubbub->funcs->force_pstate_change_control(

				dc->res_pool->hubbub, false, false);



	for (i = 0; i < dc->res_pool->pipe_count; i++) {

		struct pipe_ctx *pipe = &context->res_ctx.pipe_ctx[i];