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Subject: Re: dma_declare_coherent_memory and SuperH
To:     Christoph Hellwig <hch@lst.de>
Cc:     Yoshinori Sato <ysato@users.sourceforge.jp>,
        Rich Felker <dalias@libc.org>, linux-sh@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20210623133205.GA28589@lst.de>
 <1a55cf69-8fe1-dca0-68c7-f978567f9ca0@landley.net>
 <20210628133858.GA21602@lst.de>
 <4d6b7c35-f2fa-b476-b814-598a812770e6@landley.net>
 <20210628134955.GA22559@lst.de>
From:   Rob Landley <rob@landley.net>
Message-ID: <1141b20f-7cdf-1477-ef51-876226db7a37@landley.net>
Date:   Mon, 28 Jun 2021 09:29:59 -0500
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On 6/28/21 8:49 AM, Christoph Hellwig wrote:
> On Mon, Jun 28, 2021 at 09:04:19AM -0500, Rob Landley wrote:
>> > Well, the replacement is to declare the device memory carveouts in the
>> > Device Tree.
>> 
>> Your plan is to eliminate the ability for non-device-tree boards to do DMA?
> 
> No.  My hope is to kill dma_declarare_coherent, an API for board
> support files to declare device-specific regions to be used for
> coherent DMA.

Q) If I haven't got regression test hardware to make sure I properly converted
each of these entire boards to device tree, Is there anything else I can do to
help you remove this function from common code, such as inlining some portion of
this function?

A) You can convert the board to device tree.

Which part of this exchange have I misunderstood?

Rob