[PATCH AUTOSEL 6.3 24/44] drm/amd/display: fixed dcn30+ underflow issue

[Sasha Levin]

From: Ayush Gupta <ayugupta at amd.com>

[ 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 at amd.com>
Reviewed-by: Martin Leung <Martin.Leung at amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo at amd.com>
Signed-off-by: Ayush Gupta <ayugupta 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>
---
 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 df787fcf8e86e..0e730445459c7 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 d13e46eeee3c0..6d3f2335b9f1e 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn31/dcn31_hwseq.c
@@ -285,7 +285,7 @@ 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 9d14045cccd63..ae96157e98ecb 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn32/dcn32_hwseq.c
@@ -895,7 +895,7 @@ 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