If the displays are off, set the vblank time to max to make sure mclk switching is enabled. Avoid mclk getting set to high when no displays are attached. bug: https://bugs.freedesktop.org/show_bug.cgi?id=101528 fixes: 09be4a5219 (drm/amd/powerplay/smu7: add vblank check for mclk switching (v2)) Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> Cc: stable@xxxxxxxxxxxxxxx --- drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c index c6dba1e..8b8eda7 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cgs.c @@ -838,6 +838,9 @@ static int amdgpu_cgs_get_active_displays_info(struct cgs_device *cgs_device, return -EINVAL; mode_info = info->mode_info; + if (mode_info) + /* if the displays are off, vblank time is max */ + mode_info->vblank_time_us = 0xffffffff; if (adev->mode_info.num_crtc && adev->mode_info.mode_config_initialized) { list_for_each_entry(crtc, -- 2.5.5