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Date:   Thu, 26 Jul 2018 11:11:55 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Cc:     linux-snps-arc@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-arch@vger.kernel.org,
        Vineet Gupta <Vineet.Gupta1@synopsys.com>,
        Alexey Brodkin <Alexey.Brodkin@synopsys.com>, hch@lst.de
Subject: Re: [PATCH] ARC: fix broken noncoherent cache ops
Message-ID: <20180726091155.GA24209@lst.de>
References: <20180724141302.4305-1-Eugeniy.Paltsev@synopsys.com>
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On Tue, Jul 24, 2018 at 05:13:02PM +0300, Eugeniy Paltsev wrote:
> All DMA devices on ARC haven't worked with SW cache control
> since commit a8eb92d02dd7 ("arc: fix arc_dma_{map,unmap}_page")
> This happens because we don't check direction argument at all in
> new implementation. Fix that.
> 
> Fixies: commit a8eb92d02dd7 ("arc: fix arc_dma_{map,unmap}_page")
> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>

Looks sensible.  Might be worth explaining that ARC can speculate
into the areas under DMA, which is why this is required.