Re: [PATCH RFC 0/5] ARM: Raspberry Pi 4 DMA support

From: Catalin Marinas
Date: Mon Oct 14 2019 - 16:59:10 EST

On Mon, Oct 14, 2019 at 08:31:02PM +0200, Nicolas Saenz Julienne wrote:
> the Raspberry Pi 4 offers up to 4GB of memory, of which only the first
> is DMA capable device wide. This forces us to use of bounce buffers,
> which are currently not very well supported by ARM's custom DMA ops.
> Among other things the current mechanism (see dmabounce.c) isn't
> suitable for high memory. Instead of fixing it, this series introduces a
> way of selecting dma-direct as the default DMA ops provider which allows
> for the Raspberry Pi to make use of swiotlb.

I presume these patches go on top of this series:

which I queued here: