Re: [PATCH 1/4] net: sgi: ioc3-eth: don't abuse dma_direct_* calls

Christoph Hellwig
2019-10-30T22:38:22Z

On Wed, Oct 30, 2019 at 11:05:49PM +0100, Thomas Bogendoerfer wrote:
> On Wed, 30 Oct 2019 14:12:30 -0700
> Christoph Hellwig <hch@lst.de> wrote:
>
> > dma_direct_ is a low-level API that must never be used by drivers
> > directly. Switch to use the proper DMA API instead.
>
> is the 4kb/16kb alignment still guaranteed ? If not how is the way
> to get such an alignment ?

The DMA API gives you page aligned memory. dma_direct doesn't give you
any gurantees as it is an internal API explicitly documented as not
for driver usage that can change at any time.