Commit bc0cd807 authored by Alvin Lee's avatar Alvin Lee Committed by Alex Deucher
Browse files

drm/amd/display: Don't compare dppclk before updating DTO 



[Why]
In dcn3_update_clocks there are situations where dppclk is not
lowered (i.e. stays the same), but DTO still needs to be increased
before we program pipe frontend (i.e. in prepare_bandwidth). If we
don't program the new DTO value before we program the pipe,
we will underflow as soon as the pipe lock is released until the
next call to dcn3_update_clocks where the DTO is updated.

[How]
Remove dppclk check before programming new DTO value.

Signed-off-by: default avatarAlvin Lee <alvin.lee2@amd.com>
Reviewed-by: default avatarJun Lei <Jun.Lei@amd.com>
Acked-by: default avatarEryk Brol <eryk.brol@amd.com>
Signed-off-by: default avatarAlex Deucher <alexander.deucher@amd.com>
parent c6851841

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c

+4 −3
Original line number Diff line number Diff line
@@ -323,8 +323,9 @@ static void dcn3_update_clocks(struct clk_mgr *clk_mgr_base, 
			/* if clock is being raised, increase refclk before lowering DTO */

			if (update_dppclk || update_dispclk)

				dcn20_update_clocks_update_dentist(clk_mgr);

			/* always update dtos unless clock is lowered and not safe to lower */

			if (new_clocks->dppclk_khz >= dc->current_state->bw_ctx.bw.dcn.clk.dppclk_khz)

			/* There is a check inside dcn20_update_clocks_update_dpp_dto which ensures

			 * that we do not lower dto when it is not safe to lower. We do not need to

			 * compare the current and new dppclk before calling this function.*/

			dcn20_update_clocks_update_dpp_dto(clk_mgr, context, safe_to_lower);

		}

	}