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Date:   Tue, 27 Mar 2018 19:04:51 +0200 (CEST)
From:   Sebastian Ott <sebott@linux.vnet.ibm.com>
To:     Christoph Hellwig <hch@lst.de>
cc:     Jesper Nilsson <jesper.nilsson@axis.com>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        linux-kernel@vger.kernel.org
Subject: Re: dma_zalloc_coherent broken with
 57bf5a8963f80fb3828c46c3e3a5b2dd790e09a7
In-Reply-To: <20180327164505.GA10522@lst.de>
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On Tue, 27 Mar 2018, Christoph Hellwig wrote:
> On Tue, Mar 27, 2018 at 05:24:10PM +0200, Sebastian Ott wrote:
> > What do you mean by current implementations? Arch specific code? At least
> > on s390 we don't do that. dma-mapping.h doesn't do it either.
> 
> The arch implementations should do it.  Seems like s390 and potentially
> a few others don't.  I'm a little slow due to a cast on one arm, but I'll
> do an audit and will fix up anything I'll find.

What was wrong with the old behavior (let the caller decide - the same
as with memory allocations)? We have interfaces like dma_zalloc_coherent,
which explicitely set __GFP_ZERO. We have callers of dma_alloc followed by
a manually memset..

Sebastian