Questions about KMS flip

[Michel Dänzer]

On 2021-11-12 15:29, Michel Dänzer wrote:
> On 2021-11-12 13:47, Christian König wrote:
>>
>> Anyway this unfortunately turned out to be work for Harray and Nicholas. In detail it's about this bug report here: https://bugzilla.kernel.org/show_bug.cgi?id=214621
>>
>> Lang was able to reproduce the issue and narrow it down to the pin in amdgpu_display_crtc_page_flip_target().
>>
>> In other words we somehow have an unbalanced pinning of the scanout buffer in DC.
> 
> DC doesn't use amdgpu_display_crtc_page_flip_target AFAICT. The corresponding pin with DC would be in dm_plane_helper_prepare_fb, paired with the unpin in 
> dm_plane_helper_cleanup_fb.
> 
> 
> With non-DC, the pin in amdgpu_display_crtc_page_flip_target is paired with the unpin in dm_plane_helper_cleanup_fb

This should say amdgpu_display_unpin_work_func.


> & dce_v*_crtc_disable. One thing I notice is that the pin is guarded by if (!adev->enable_virtual_display), but the unpins seem unconditional. So could this be about virtual display, and the problem is actually trying to unpin a BO that was never pinned?
> 
> 


-- 
Earthling Michel Dänzer            |                  https://redhat.com
Libre software enthusiast          |         Mesa and Xwayland developer