Re: [PATCH mm-unstable v1 17/20] drm/exynos: remove FOLL_FORCE usage

Daniel Vetter
2022-11-16T11:05:13Z

On Wed, Nov 16, 2022 at 11:26:56AM +0100, David Hildenbrand wrote:
> FOLL_FORCE is really only for ptrace access. As we unpin the pinned pages
> using unpin_user_pages_dirty_lock(true), the assumption is that all these
> pages are writable.
>
> FOLL_FORCE in this case seems to be a legacy leftover. Let's just remove
> it.
>
> Cc: Inki Dae <inki.dae@samsung.com>
> Cc: Seung-Woo Kim <sw0312.kim@samsung.com>
> Cc: Kyungmin Park <kyungmin.park@samsung.com>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Signed-off-by: David Hildenbrand <david@redhat.com>

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Plus ack for merging through the appropriate non-drm tree.
-Daniel

> ---
> drivers/gpu/drm/exynos/exynos_drm_g2d.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_g2d.c b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
> index 471fd6c8135f..e19c2ceb3759 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_g2d.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_g2d.c
> @@ -477,7 +477,7 @@ static dma_addr_t *g2d_userptr_get_dma_addr(struct g2d_data *g2d,
> }
>
> ret = pin_user_pages_fast(start, npages,
> - FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM,
> + FOLL_WRITE | FOLL_LONGTERM,
> g2d_userptr->pages);
> if (ret != npages) {
> DRM_DEV_ERROR(g2d->dev,
> --
> 2.38.1
>

--
Daniel Vetter
Software Engineer, Intel Corporation