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Subject: Re: [PATCH 6/7] riscv: Select ARCH_DMA_DEFAULT_COHERENT
From:   Jiaxun Yang <jiaxun.yang@flygoat.com>
In-Reply-To: <Y/UJ9HowQdsNN+Cz@spud>
Date:   Tue, 21 Feb 2023 18:20:02 +0000
Cc:     "linux-mips@vger.kernel.org" <linux-mips@vger.kernel.org>,
        linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
        Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
        mpe@ellerman.id.au, paul.walmsley@sifive.com, palmer@dabbelt.com,
        Rob Herring <robh+dt@kernel.org>,
        Christoph Hellwig <hch@lst.de>, m.szyprowski@samsung.com,
        robin.murphy@arm.com
Content-Transfer-Encoding: quoted-printable
Message-Id: <D9DE553D-07F7-46EA-96E6-AA2A6ED5F6C6@flygoat.com>
References: <20230221124613.2859-1-jiaxun.yang@flygoat.com>
 <20230221124613.2859-7-jiaxun.yang@flygoat.com> <Y/UJ9HowQdsNN+Cz@spud>
To:     Conor Dooley <conor@kernel.org>
Precedence: bulk


> 2023=E5=B9=B42=E6=9C=8821=E6=97=A5 18:14=EF=BC=8CConor Dooley =
<conor@kernel.org> =E5=86=99=E9=81=93=EF=BC=9A
>=20
> On Tue, Feb 21, 2023 at 12:46:12PM +0000, Jiaxun Yang wrote:
>> For RISCV we always assume devices are DMA coherent.
>=20
> "Always assume", I'm not keen on that wording as it is unclear as to
> whether you are suggesting that a) we always take devices to be DMA
> coherent, or b) unless a device states it is non-coherent, we take it =
to
> be DMA coherent.
> I think you mean b, but being exact would be appreciated, thanks.

Yep I meant option b, thanks for the point.

>=20
>> Select ARCH_DMA_DEFAULT_COHERENT to ensure dev->dma_conherent
>> is always initialized to true.
>>=20
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
>=20
> Why was this not sent to the riscv list?
> When (or if) you send v2, can you please make sure that you do cc it?
Will do.

Thanks
- Jiaxun

>=20
> Thanks,
> Conor.