Re: [PATCH v9 10/32] drm: mediatek: use common helper for a scatterlist contiguity check

Chun-Kuang Hu
2020-09-01T22:59:35Z

Hi, Marek:

Marek Szyprowski <m.szyprowski@samsung.com> 於 2020年8月26日 週三 下午2:35寫道：
>
> Use common helper for checking the contiguity of the imported dma-buf and
> do this check before allocating resources, so the error path is simpler.
>

Acked-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
> drivers/gpu/drm/mediatek/mtk_drm_gem.c | 28 ++++++--------------------
> 1 file changed, 6 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> index 6190cc3b7b0d..3654ec732029 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> @@ -212,37 +212,21 @@ struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
> struct dma_buf_attachment *attach, struct sg_table *sg)
> {
> struct mtk_drm_gem_obj *mtk_gem;
> - int ret;
> - struct scatterlist *s;
> - unsigned int i;
> - dma_addr_t expected;
>
> - mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
> + /* check if the entries in the sg_table are contiguous */
> + if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
> + DRM_ERROR("sg_table is not contiguous");
> + return ERR_PTR(-EINVAL);
> + }
>
> + mtk_gem = mtk_drm_gem_init(dev, attach->dmabuf->size);
> if (IS_ERR(mtk_gem))
> return ERR_CAST(mtk_gem);
>
> - expected = sg_dma_address(sg->sgl);
> - for_each_sg(sg->sgl, s, sg->nents, i) {
> - if (!sg_dma_len(s))
> - break;
> -
> - if (sg_dma_address(s) != expected) {
> - DRM_ERROR("sg_table is not contiguous");
> - ret = -EINVAL;
> - goto err_gem_free;
> - }
> - expected = sg_dma_address(s) + sg_dma_len(s);
> - }
> -
> mtk_gem->dma_addr = sg_dma_address(sg->sgl);
> mtk_gem->sg = sg;
>
> return &mtk_gem->base;
> -
> -err_gem_free:
> - kfree(mtk_gem);
> - return ERR_PTR(ret);
> }
>
> void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
> --
> 2.17.1
>