From 1dbf0079298332b9758a20ae871a01630ef8fcd5 Mon Sep 17 00:00:00 2001
From: Alvin Lee <alvin.lee2@amd.com>
Date: Tue, 14 Jul 2020 15:06:40 -0400
Subject: drm/amd/display: Don't compare dppclk before updating DTO
Git-commit: bc0cd80783ff7c2201b44d384bab4629c9cb7db9
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322
[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: Alvin Lee <alvin.lee2@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@amd.com>
Acked-by: Eryk Brol <eryk.brol@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
.../gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c
index d94fdc52be37..9133646f6d5f 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c
@@ -323,9 +323,10 @@ 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)
- dcn20_update_clocks_update_dpp_dto(clk_mgr, context, safe_to_lower);
+ /* 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);
}
}
--
2.29.2