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| author | Timur Kristóf <timur.kristof@gmail.com> | 2025-08-28 17:11:08 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-15 11:57:58 +0200 |
| commit | 4e27e18f64a2087c4f79892360ef1942433b5887 (patch) | |
| tree | 5795cac347be6833d9eb7e39932de690555ced7d /drivers/gpu | |
| parent | 1320d1e834c12a2506e9933ab6d478fc6822dcfd (diff) | |
| download | linux-4e27e18f64a2087c4f79892360ef1942433b5887.tar.gz linux-4e27e18f64a2087c4f79892360ef1942433b5887.tar.bz2 linux-4e27e18f64a2087c4f79892360ef1942433b5887.zip | |
drm/amd/pm: Treat zero vblank time as too short in si_dpm (v3)
[ Upstream commit 9003a0746864f39a0ef72bd45f8e1ad85d930d67 ]
Some parts of the code base expect that MCLK switching is turned
off when the vblank time is set to zero.
According to pp_pm_compute_clocks the non-DC code has issues
with MCLK switching with refresh rates over 120 Hz.
v3:
Add code comment to explain this better.
Add an if statement instead of changing the switch_limit.
Fixes: 841686df9f7d ("drm/amdgpu: add SI DPM support (v4)")
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c index 3ce9396900f7..075d183bb1bb 100644 --- a/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c +++ b/drivers/gpu/drm/amd/pm/legacy-dpm/si_dpm.c @@ -3066,7 +3066,13 @@ static bool si_dpm_vblank_too_short(void *handle) /* we never hit the non-gddr5 limit so disable it */ u32 switch_limit = adev->gmc.vram_type == AMDGPU_VRAM_TYPE_GDDR5 ? 450 : 0; - if (vblank_time < switch_limit) + /* Consider zero vblank time too short and disable MCLK switching. + * Note that the vblank time is set to maximum when no displays are attached, + * so we'll still enable MCLK switching in that case. + */ + if (vblank_time == 0) + return true; + else if (vblank_time < switch_limit) return true; else return false; |