Re: [PATCH v4 7/7] dma-buf: system_heap: Add a system-uncached heap re-using the system heap

[John Stultz]

On Thu, Oct 29, 2020 at 12:10 AM Hillf Danton <hdanton@xxxxxxxx> wrote:
> On Thu, 29 Oct 2020 00:16:24 +0000 John Stultz wrote:
> > @@ -194,6 +210,9 @@ static int system_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
> >       struct sg_page_iter piter;
> >       int ret;
> >
> > +     if (buffer->uncached)
> > +             vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
> > +
>
> Wonder why you turn back to dma_mmap_wc() and friends?

Sorry, can you expand on what you are proposing here instead?  I'm not
sure I see how dma_alloc/mmap/*_wc() quite fits here.

thanks
-john