Re: [PATCH 3/3] drm/v3d: Fix prime imports of buffers from other drivers.

From: Dave Emett
Date: Thu Nov 29 2018 - 12:38:12 EST


On Wed, 28 Nov 2018 at 23:09, Eric Anholt <eric@xxxxxxxxxx> wrote:
>
> v3d_bo_get_pages() checks this to decide to map the imported buffer
> instead of the backing shmem file. The caller was about to set this
> value anyway, and there's no error path in between. Ideally we
> wouldn't even allocate the shmem file for our imports, but that's a
> more invasive fix.
>
> Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
> Fixes: 57692c94dcbe ("drm/v3d: Introduce a new DRM driver for Broadcom V3D V3.x+")
> Cc: Dave Emett <david.emett@xxxxxxxxxxxx>

Reviewed-by: Dave Emett <david.emett@xxxxxxxxxxxx>
> ---
>
> I've been sitting on this one because I don't like it and was hoping
> the shmem library would pan out. This is a useful patch for now,
> though.
>
> drivers/gpu/drm/v3d/v3d_bo.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/gpu/drm/v3d/v3d_bo.c b/drivers/gpu/drm/v3d/v3d_bo.c
> index 54d96518a131..a08766d39eab 100644
> --- a/drivers/gpu/drm/v3d/v3d_bo.c
> +++ b/drivers/gpu/drm/v3d/v3d_bo.c
> @@ -293,6 +293,7 @@ v3d_prime_import_sg_table(struct drm_device *dev,
> bo->resv = attach->dmabuf->resv;
>
> bo->sgt = sgt;
> + obj->import_attach = attach;
> v3d_bo_get_pages(bo);
>
> v3d_mmu_insert_ptes(bo);
> --
> 2.20.0.rc1
>