Re: [PATCH v9 11/32] drm: mediatek: use common helper for extracting pages array

From: Chun-Kuang Hu
Date: Tue Sep 01 2020 - 19:17:26 EST


Robin Murphy <robin.murphy@xxxxxxx> 於 2020年9月2日 週三 上午2:55寫道:
>
> On 2020-08-26 07:32, Marek Szyprowski wrote:
> > Use common helper for converting a sg_table object into struct
> > page pointer array.
>
> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
>
> Side note: is mtk_drm_gem_prime_vmap() missing a call to
> sg_free_table(sgt) before its kfree(sgt)?

Yes, we need another patch to fix that bug, But for this patch,

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

>
> > Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> > ---
> > drivers/gpu/drm/mediatek/mtk_drm_gem.c | 9 ++-------
> > 1 file changed, 2 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> > index 3654ec732029..0583e557ad37 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> > @@ -233,9 +233,7 @@ void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
> > {
> > struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
> > struct sg_table *sgt;
> > - struct sg_page_iter iter;
> > unsigned int npages;
> > - unsigned int i = 0;
> >
> > if (mtk_gem->kvaddr)
> > return mtk_gem->kvaddr;
> > @@ -249,11 +247,8 @@ void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
> > if (!mtk_gem->pages)
> > goto out;
> >
> > - for_each_sg_page(sgt->sgl, &iter, sgt->orig_nents, 0) {
> > - mtk_gem->pages[i++] = sg_page_iter_page(&iter);
> > - if (i > npages)
> > - break;
> > - }
> > + drm_prime_sg_to_page_addr_arrays(sgt, mtk_gem->pages, NULL, npages);
> > +
> > mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
> > pgprot_writecombine(PAGE_KERNEL));
> >
> >