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

[Sasha Levin]

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

[ Upstream commit ce649bd2d834db83ecc2756a362c9a1ec61658a5 ]

[Why && How]
Screen flickering saw on 4K at 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 at amd.com>
Acked-by: Wayne Lin <wayne.lin at amd.com>
Signed-off-by: Leo Ma <hanghong.ma at amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler at amd.com>
Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sasha Levin <sashal at 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