Re: [PATCH] dma-direct: Set SG_DMA_SWIOTLB flag for dma-direct
From: Christoph Hellwig
Date: Wed May 08 2024 - 07:34:08 EST
On Tue, May 07, 2024 at 01:07:25PM -0700, T.J. Mercier wrote:
> On Mon, May 6, 2024 at 10:43???PM Christoph Hellwig <hch@xxxxxx> wrote:
> >
> > On Mon, May 06, 2024 at 09:39:53AM -0700, T.J. Mercier wrote:
> > > > You should not check, you simply must handle it by doing the proper
> > > > DMA API based ownership management.
> > >
> > > That doesn't really work for uncached buffers.
> >
> > What uncached buffers?
>
> For example these ones:
> https://android.googlesource.com/kernel/common/+/refs/heads/android-mainline/drivers/dma-buf/heaps/system_heap.c#141
Whatever that code is doing is probably not upstream because it's too
broken to live.