Re: [PATCH 0/9] drm: Revert general use of struct drm_gem_object.dma_buf

[Thomas Zimmermann <tzimmermann@suse.de>]

Hi

Am 11.07.25 um 17:48 schrieb Linus Torvalds:
> On Fri, 11 Jul 2025 at 02:40, Thomas Zimmermann <tzimmermann@suse.de> wrote:
>> Reverting the whole thing is the only sensible action here.
> I'm assuming this is against some current drm tree, not mine, because
> it doesn't apply here.

Yes, it's against drm-misc-fixes, which requires an additional revert of 
the extra fix from this week.

>
> I'll try the smaller set of reverts that Simona suggested for my
> testing, and will get back to you on that.

The list of patches I sent earlier are from v6.15-rc5 and should be the 
ones you need. You will get the revert patch set as part of a DRM PR soon.

Best regards
Thomas

>
> Background for others: current -git ends up having odd hangs when
> Xwayland starts for me (not at boot, but when I log in). It seems to
> be very timing-dependent, so presumably I'm just unlucky with my
> hardware.
>
> The timing-dependence has made my attempts to bisect it very
> frustrating and non-conclusive, but reverting 5307dce878d4 ("drm/gem:
> Acquire references on GEM handles for framebuffers") made things work
> _better_, to the point where I thought it was fixed.
>
> Until the hang came back.
>
> The "hang" is not some kind of kernel hang, it seems to be user-space
> getting confused by the changes. Because I can still switch back to a
> text VT, and there are no messages in the kernel logs. And the system
> "recovers", in that after a 30-second timeout (it feels like a minute,
> but logs seem to imply it really is just half a minute), I get
>
>     gnome-session-manager@gnome.service: start operation timed out. Terminating.
>     gnome-session-manager@gnome.service: Failed with result 'timeout'.
>
> and it restarts, and things work fine on the second try. Except when
> they don't - on one reboot it went through this twice, and
>
> Now, because it's obviously timing-sensitive, it might be something
> entirely different going on and I have no guarantees, but it does seem
> to be related to that commit 5307dce878d4.
>
> And I only see this on one of my machines. Again, might be timing, but
> might also be that it only shows up on certain hardware (in my case:
> Radeon RX 580).
>
>             Linus

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstrasse 146, 90461 Nuernberg, Germany
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