Re: [PATCH] drm/prime: remove drm_prime_lookup_buf_by_handle

[Simona Vetter <simona.vetter@ffwll.ch>]

On Fri, Jun 13, 2025 at 02:24:41PM +0200, Christian König wrote:
> On 6/13/25 14:15, Christian König wrote:
> > On 6/13/25 14:11, Saarinen, Jani wrote:
> >> Hi, 
> >>
> >>> -----Original Message-----
> >>> From: dri-devel <dri-devel-bounces@lists.freedesktop.org> On Behalf Of Jani
> >>> Nikula
> >>> Sent: Friday, 13 June 2025 14.02
> >>> To: Tvrtko Ursulin <tursulin@ursulin.net>; Simona Vetter
> >>> <simona.vetter@ffwll.ch>; Christian König
> >>> <ckoenig.leichtzumerken@gmail.com>
> >>> Cc: tzimmermann@suse.de; dri-devel@lists.freedesktop.org
> >>> Subject: Re: [PATCH] drm/prime: remove drm_prime_lookup_buf_by_handle
> >>>
> >>> On Fri, 13 Jun 2025, Tvrtko Ursulin <tursulin@ursulin.net> wrote:
> >>>> On 13/06/2025 11:09, Jani Nikula wrote:
> >>>>> On Wed, 04 Jun 2025, Simona Vetter <simona.vetter@ffwll.ch> wrote:
> >>>>>> On Wed, Jun 04, 2025 at 05:36:22PM +0200, Simona Vetter wrote:
> >>>>> This regressed one of our CI IGT tests [1].
> >>>>>
> >>>>> BR,
> >>>>> Jani.
> >>>>>
> >>>>>
> >>>>> [1] https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/14463
> >>>>
> >>>> It also explodes even more trivially when logging into a KDE Wayland
> >>>> session:
> >>>
> >>> Smells like a revert, and back to the drawing board, perhaps?
> > 
> > Potentially, but any idea what's going wrong? Sounds like I missed something, but I don't see what.
> 
> Oh! I now see what's going on.
> 
> Looks like the code previously had a race condition and by removing the extra check I made the race condition 100% likely.
> 
> Ups, I think a simple revert won't do it here. Give me a second.

Please make sure you cc: xe-devel so intel-gfx-ci can pick it up and test.
It's a bit embarrassing.

Also since this breaks things quite badly might be good to push the revert
right away since I don't think we can land the proper fix before the w/e.
For that

Acked-by: Simona Vetter <simona.vetter@ffwll.ch>

Cheers, Sima
> 
> Regards,
> Christian.
> 
> > 
> > Regards,
> > Christian.
> > 
> >> I would say so. Looks like this on our CI https://intel-gfx-ci.01.org/tree/drm-tip/igt@prime_self_import@basic-with_one_bo.html 
> >> And systems stop testing anything after (see eg https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_16692/bat-twl-1/igt_runner0.txt ) when aborts happens. 
> >>
> >>>
> >>>
> >>> BR,
> >>> Jani.
> >>
> >> Br
> >> Other Jani
> >>>
> >>>
> >>> --
> >>> Jani Nikula, Intel
> > 
> 

-- 
Simona Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch