[PATCH AUTOSEL 5.10 037/100] drm/amd/display: DCHUB underflow counter increasing in some scenarios

Sasha Levin
2021-05-03T16:49:53Z

From: Aric Cyr <aric.cyr@amd.com>

[ Upstream commit 4710430a779e6077d81218ac768787545bff8c49 ]

[Why]
When unplugging a display, the underflow counter can be seen to
increase because PSTATE switch is allowed even when some planes are not
blanked.

[How]
Check that all planes are not active instead of all streams before
allowing PSTATE change.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Aric Cyr <aric.cyr@amd.com>
Acked-by: Solomon Chiu <solomon.chiu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

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 95d883482227..cab47bb21172 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
@@ -240,6 +240,7 @@ static void dcn3_update_clocks(struct clk_mgr *clk_mgr_base,
bool force_reset = false;
bool update_uclk = false;
bool p_state_change_support;
+ int total_plane_count;

if (dc->work_arounds.skip_clock_update || !clk_mgr->smu_present)
return;
@@ -280,7 +281,8 @@ static void dcn3_update_clocks(struct clk_mgr *clk_mgr_base,
clk_mgr_base->clks.socclk_khz = new_clocks->socclk_khz;

clk_mgr_base->clks.prev_p_state_change_support = clk_mgr_base->clks.p_state_change_support;
- p_state_change_support = new_clocks->p_state_change_support || (display_count == 0);
+ total_plane_count = clk_mgr_helper_get_active_plane_cnt(dc, context);
+ p_state_change_support = new_clocks->p_state_change_support || (total_plane_count == 0);
if (should_update_pstate_support(safe_to_lower, p_state_change_support, clk_mgr_base->clks.p_state_change_support)) {
clk_mgr_base->clks.p_state_change_support = p_state_change_support;

--
2.30.2