[PATCH AUTOSEL 6.1 19/33] drm/amd/display: fixed dcn30+ underflow issue

[Sasha Levin]

From: Ayush Gupta <ayugupta@xxxxxxx>

[ Upstream commit 37403ced9f2873fab7f39ab4ac963bbb33fb0bc0 ]

[Why]
Observing underflow on dcn30+ system config at 4k144hz

[How]
We set the UCLK hardmax on AC/DC switch if softmax is enabled
and also on boot. While booting up the UCLK Hardmax is set
to softmax before the init sequence and the init sequence
resets the hardmax to UCLK max which enables P-state switching.
Just added a conditional check to avoid setting hardmax on init.

Reviewed-by: Alvin Lee <Alvin.Lee2@xxxxxxx>
Reviewed-by: Martin Leung <Martin.Leung@xxxxxxx>
Acked-by: Qingqing Zhuo <qingqing.zhuo@xxxxxxx>
Signed-off-by: Ayush Gupta <ayugupta@xxxxxxx>
Tested-by: Daniel Wheeler <daniel.wheeler@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c | 3 ++-
 drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c | 2 +-
 drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c
index c20e9f76f0213..a1b312483d7f1 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn30/dcn30_hwseq.c
@@ -629,7 +629,8 @@ void dcn30_init_hw(struct dc *dc)
 	if (dc->clk_mgr->funcs->notify_wm_ranges)
 		dc->clk_mgr->funcs->notify_wm_ranges(dc->clk_mgr);
 
-	if (dc->clk_mgr->funcs->set_hard_max_memclk)
+	//if softmax is enabled then hardmax will be set by a different call
+	if (dc->clk_mgr->funcs->set_hard_max_memclk && !dc->clk_mgr->dc_mode_softmax_enabled)
 		dc->clk_mgr->funcs->set_hard_max_memclk(dc->clk_mgr);
 
 	if (dc->res_pool->hubbub->funcs->force_pstate_change_control)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c
index bdf101547484a..d4ee533deff32 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c
@@ -284,7 +284,7 @@ void dcn31_init_hw(struct dc *dc)
 	if (dc->clk_mgr->funcs->notify_wm_ranges)
 		dc->clk_mgr->funcs->notify_wm_ranges(dc->clk_mgr);
 
-	if (dc->clk_mgr->funcs->set_hard_max_memclk)
+	if (dc->clk_mgr->funcs->set_hard_max_memclk && !dc->clk_mgr->dc_mode_softmax_enabled)
 		dc->clk_mgr->funcs->set_hard_max_memclk(dc->clk_mgr);
 
 	if (dc->res_pool->hubbub->funcs->force_pstate_change_control)
diff --git a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
index 1a85509c12f23..a32e21ada8555 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
@@ -970,7 +970,7 @@ void dcn32_init_hw(struct dc *dc)
 	if (dc->clk_mgr->funcs->notify_wm_ranges)
 		dc->clk_mgr->funcs->notify_wm_ranges(dc->clk_mgr);
 
-	if (dc->clk_mgr->funcs->set_hard_max_memclk)
+	if (dc->clk_mgr->funcs->set_hard_max_memclk && !dc->clk_mgr->dc_mode_softmax_enabled)
 		dc->clk_mgr->funcs->set_hard_max_memclk(dc->clk_mgr);
 
 	if (dc->res_pool->hubbub->funcs->force_pstate_change_control)
-- 
2.39.2