[PATCH AUTOSEL 6.6 33/43] drm/amd/display: Fix DC mode screen flickering on DCN321

Sasha Levin
2024-05-07T23:11:49Z

From: Leo Ma <hanghong.ma@amd.com>

[ Upstream commit ce649bd2d834db83ecc2756a362c9a1ec61658a5 ]

[Why && How]
Screen flickering saw on 4K@60 eDP with high refresh rate external
monitor when booting up in DC mode. DC Mode Capping is disabled
which caused wrong UCLK being used.

Reviewed-by: Alvin Lee <alvin.lee2@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Leo Ma <hanghong.ma@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
.../amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c
index e9345f6554dbc..2428a4763b85f 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c
@@ -547,8 +547,12 @@ static void dcn32_update_clocks(struct clk_mgr *clk_mgr_base,
* since we calculate mode support based on softmax being the max UCLK
* frequency.
*/
- dcn32_smu_set_hard_min_by_freq(clk_mgr, PPCLK_UCLK,
- dc->clk_mgr->bw_params->dc_mode_softmax_memclk);
+ if (dc->debug.disable_dc_mode_overwrite) {
+ dcn30_smu_set_hard_max_by_freq(clk_mgr, PPCLK_UCLK, dc->clk_mgr->bw_params->max_memclk_mhz);
+ dcn32_smu_set_hard_min_by_freq(clk_mgr, PPCLK_UCLK, dc->clk_mgr->bw_params->max_memclk_mhz);
+ } else
+ dcn32_smu_set_hard_min_by_freq(clk_mgr, PPCLK_UCLK,
+ dc->clk_mgr->bw_params->dc_mode_softmax_memclk);
} else {
dcn32_smu_set_hard_min_by_freq(clk_mgr, PPCLK_UCLK, dc->clk_mgr->bw_params->max_memclk_mhz);
}
@@ -581,8 +585,13 @@ static void dcn32_update_clocks(struct clk_mgr *clk_mgr_base,
/* set UCLK to requested value if P-State switching is supported, or to re-enable P-State switching */
if (clk_mgr_base->clks.p_state_change_support &&
(update_uclk || !clk_mgr_base->clks.prev_p_state_change_support) &&
- !dc->work_arounds.clock_update_disable_mask.uclk)
+ !dc->work_arounds.clock_update_disable_mask.uclk) {
+ if (dc->clk_mgr->dc_mode_softmax_enabled && dc->debug.disable_dc_mode_overwrite)
+ dcn30_smu_set_hard_max_by_freq(clk_mgr, PPCLK_UCLK,
+ max((int)dc->clk_mgr->bw_params->dc_mode_softmax_memclk, khz_to_mhz_ceil(clk_mgr_base->clks.dramclk_khz)));
+
dcn32_smu_set_hard_min_by_freq(clk_mgr, PPCLK_UCLK, khz_to_mhz_ceil(clk_mgr_base->clks.dramclk_khz));
+ }

if (clk_mgr_base->clks.num_ways != new_clocks->num_ways &&
clk_mgr_base->clks.num_ways > new_clocks->num_ways) {
--
2.43.0