Re: [PATCH 14/15] drm/gem: Tiny kernel clarification for drm_gem_fence_array_add

[Daniel Vetter <daniel@ffwll.ch>]

On Thu, Jun 24, 2021 at 03:35:19PM +0200, Christian König wrote:
> Am 24.06.21 um 15:32 schrieb Daniel Vetter:
> > On Thu, Jun 24, 2021 at 02:48:54PM +0200, Christian König wrote:
> > > 
> > > Am 24.06.21 um 14:41 schrieb Daniel Vetter:
> > > > On Wed, Jun 23, 2021 at 10:42:50AM +0200, Christian König wrote:
> > > > > Am 22.06.21 um 18:55 schrieb Daniel Vetter:
> > > > > > Spotted while trying to convert panfrost to these.
> > > > > > 
> > > > > > Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> > > > > > Cc: "Christian König" <christian.koenig@amd.com>
> > > > > > Cc: Lucas Stach <l.stach@pengutronix.de>
> > > > > > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > > > > > Cc: Maxime Ripard <mripard@kernel.org>
> > > > > > Cc: Thomas Zimmermann <tzimmermann@suse.de>
> > > > > > Cc: David Airlie <airlied@linux.ie>
> > > > > > Cc: Daniel Vetter <daniel@ffwll.ch>
> > > > > > ---
> > > > > >     drivers/gpu/drm/drm_gem.c | 3 +++
> > > > > >     1 file changed, 3 insertions(+)
> > > > > > 
> > > > > > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> > > > > > index ba2e64ed8b47..68deb1de8235 100644
> > > > > > --- a/drivers/gpu/drm/drm_gem.c
> > > > > > +++ b/drivers/gpu/drm/drm_gem.c
> > > > > > @@ -1302,6 +1302,9 @@ EXPORT_SYMBOL(drm_gem_unlock_reservations);
> > > > > >      * @fence_array: array of dma_fence * for the job to block on.
> > > > > >      * @fence: the dma_fence to add to the list of dependencies.
> > > > > >      *
> > > > > > + * This functions consumes the reference for @fence both on success and error
> > > > > > + * cases.
> > > > > > + *
> > > > > Oh, the later is a bit ugly I think. But good to know.
> > > > > 
> > > > > Reviewed-by: Christian König <christian.koenig@amd.com>
> > > > Merged to drm-misc-next, thanks for taking a look. Can you perhaps take a
> > > > look at the drm/armada patch too, then I think I have reviews/acks for all
> > > > of them?
> > > What are you talking about? I only see drm/armada patches for the irq stuff
> > > Thomas is working on.
> > There was one in this series, but Maxime was quicker. I'm going to apply
> > all the remaining ones now. After that I'll send out a patch set to add
> > some dependency tracking to drm_sched_job so that there's not so much
> > copypasta going on there. I stumbled over that when reviewing how we
> > handle dependencies.
> 
> Do you mean a common container for dma_fence objects a drm_sched_job depends
> on?

Yup. Well the real usefulness is the interfaces, so that you can just grep
for those when trying to figure out htf a driver handles its implicit
dependencies. And amdgpu is unfortunately going to be a bit in the cold
because it's special (but should be able to benefit too, just more than
1-2 patches to convert it over).

Anyway I'm going to type the cover letter rsn.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch