From mboxrd@z Thu Jan  1 00:00:00 1970
From: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Subject: Re: [PATCH kernel 4/4] sh_eth: Fix DMA-API usage for RX buffers
Date: Fri, 27 Feb 2015 23:36:59 +0300
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Cc: netdev@vger.kernel.org, linux-kernel@lists.codethink.co.uk,
	Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>,
	Mitsuhiro Kimura <mitsuhiro.kimura.kc@renesas.com>,
	Hisashi Nakamura <hisashi.nakamura.ak@renesas.com>,
	Yoshihiro Kaneko <ykaneko0929@gmail.com>
To: Ben Hutchings <ben.hutchings@codethink.co.uk>,
	"David S.Miller" <davem@davemloft.net>
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Hello.

On 01/27/2015 03:50 AM, Ben Hutchings wrote:

> - Use the return value of dma_map_single(), rather than calling
>    virt_to_page() separately
> - Check for mapping failue
> - Call dma_unmap_single() rather than dma_sync_single_for_cpu()

> Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>

    I wonder whether you're aware at the previous Renesas' attemept at fixing 
DMA issues:

http://marc.info/?t=141586251000003

    It was turned down because they tried to deal with several issues in one 
patch, and they have failed to follow up. Could you look at the rest of the 
DMA issues reported (and not reported) in that patch?

[...]

WBR, Sergei