Re: [PATCH 1/4] net: sgi: ioc3-eth: don't abuse dma_direct_* calls
From: Thomas Bogendoerfer
Date: Thu Oct 31 2019 - 04:54:34 EST
On Wed, 30 Oct 2019 23:38:18 +0100
Christoph Hellwig <hch@xxxxxx> wrote:
> 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@xxxxxx> 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.
I didn't want to argue about that. What I'm interested in is a way how
to allocate dma memory, which is 16kB aligned, via the DMA API ?
Thomas.
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