[PATCH] drm/ttm: fix leaking fences via ttm_buffer_object_transfer

[Alex Deucher]

On Tue, Feb 25, 2020 at 2:09 PM Christian König
<ckoenig.leichtzumerken at gmail.com> wrote:
>
> Am 25.02.20 um 19:56 schrieb Alex Deucher:
> > From: Ahzo <Ahzo at tutanota.com>
> >
> > Set the drm_device to NULL, so that the newly created buffer object
> > doesn't appear to use the embedded gem object.
> >
> > This is necessary, because otherwise no corresponding dma_resv_fini for
> > the dma_resv_init is called, resulting in a memory leak.
> >
> > The dma_resv_fini in ttm_bo_release_list is only called if the embedded
> > gem object is not used, which is determined by checking if the
> > drm_device is NULL.
> >
> > Bug: https://gitlab.freedesktop.org/drm/amd/issues/958
> > Fixes: 1e053b10ba60 ("drm/ttm: use gem reservation object")
> > Signed-off-by: Ahzo <Ahzo at tutanota.com>
> > Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>
> Good catch I was trying to hunt that one down as well.
>
> Reviewed-by: Christian König <christian.koenig at amd.com>

Can you apply it to drm-misc?

Thanks,

Alex

>
> > ---
> >   drivers/gpu/drm/ttm/ttm_bo_util.c | 1 +
> >   1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
> > index c8e359ded1df..44c1e7adfb7c 100644
> > --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
> > +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
> > @@ -514,6 +514,7 @@ static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
> >               fbo->base.base.resv = &fbo->base.base._resv;
> >
> >       dma_resv_init(&fbo->base.base._resv);
> > +     fbo->base.base.dev = NULL;
> >       ret = dma_resv_trylock(&fbo->base.base._resv);
> >       WARN_ON(!ret);
> >
>