Re: [PATCH 2/2] drm/amdgpu: remove pointless ttm_eu usage from DM

[Christian König <christian.koenig@xxxxxxx>]

Am 19.04.22 um 16:37 schrieb Harry Wentland:
> On 2022-04-19 10:19, Christian König wrote:
> > We just need to reserve the BO here, no need for using ttm_eu.
> >
> > Signed-off-by: Christian König <christian.koenig@xxxxxxx>
>
> Acked-by: Harry Wentland <harry.wentland@xxxxxxx>

What about the second patch? Who takes care of amdgpu_vkms.c? You guys 
or should I ping Alex?

Thanks,
Christian.

> Harry
>
> > ---
> >   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 32 ++++++++++---------
> >   1 file changed, 17 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c 
> > b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > index 73423b805b54..91e9922b95b3 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > @@ -7583,9 +7583,6 @@ static int dm_plane_helper_prepare_fb(struct 
> > drm_plane *plane,
> >       struct amdgpu_device *adev;
> >       struct amdgpu_bo *rbo;
> >       struct dm_plane_state *dm_plane_state_new, *dm_plane_state_old;
> > -    struct list_head list;
> > -    struct ttm_validate_buffer tv;
> > -    struct ww_acquire_ctx ticket;
> >       uint32_t domain;
> >       int r;
> >   @@ -7598,18 +7595,19 @@ static int 
> > dm_plane_helper_prepare_fb(struct drm_plane *plane,
> >       obj = new_state->fb->obj[0];
> >       rbo = gem_to_amdgpu_bo(obj);
> >       adev = amdgpu_ttm_adev(rbo->tbo.bdev);
> > -    INIT_LIST_HEAD(&list);
> >   -    tv.bo = &rbo->tbo;
> > -    tv.num_shared = 1;
> > -    list_add(&tv.head, &list);
> > -
> > -    r = ttm_eu_reserve_buffers(&ticket, &list, false, NULL);
> > +    r = amdgpu_bo_reserve(rbo, true);
> >       if (r) {
> >           dev_err(adev->dev, "fail to reserve bo (%d)\n", r);
> >           return r;
> >       }
> >   +    r = dma_resv_reserve_fences(rbo->tbo.base.resv, 1);
> > +    if (r) {
> > +        dev_err(adev->dev, "reserving fence slot failed (%d)\n", r);
> > +        goto error_unlock;
> > +    }
> > +
> >       if (plane->type != DRM_PLANE_TYPE_CURSOR)
> >           domain = amdgpu_display_supported_domains(adev, rbo->flags);
> >       else
> > @@ -7619,19 +7617,16 @@ static int dm_plane_helper_prepare_fb(struct 
> > drm_plane *plane,
> >       if (unlikely(r != 0)) {
> >           if (r != -ERESTARTSYS)
> >               DRM_ERROR("Failed to pin framebuffer with error %d\n", r);
> > -        ttm_eu_backoff_reservation(&ticket, &list);
> > -        return r;
> > +        goto error_unlock;
> >       }
> >         r = amdgpu_ttm_alloc_gart(&rbo->tbo);
> >       if (unlikely(r != 0)) {
> > -        amdgpu_bo_unpin(rbo);
> > -        ttm_eu_backoff_reservation(&ticket, &list);
> >           DRM_ERROR("%p bind failed\n", rbo);
> > -        return r;
> > +        goto error_unpin;
> >       }
> >   -    ttm_eu_backoff_reservation(&ticket, &list);
> > +    amdgpu_bo_unreserve(rbo);
> >         afb->address = amdgpu_bo_gpu_offset(rbo);
> >   @@ -7663,6 +7658,13 @@ static int dm_plane_helper_prepare_fb(struct 
> > drm_plane *plane,
> >       }
> >         return 0;
> > +
> > +error_unpin:
> > +    amdgpu_bo_unpin(rbo);
> > +
> > +error_unlock:
> > +    amdgpu_bo_unreserve(rbo);
> > +    return r;
> >   }
> >     static void dm_plane_helper_cleanup_fb(struct drm_plane *plane,