From mboxrd@z Thu Jan  1 00:00:00 1970
From: Borislav Petkov <bp@alien8.de>
Subject: Re: [PATCH 09/14] ata: Use 32bit DMA in AHCI for Loongson 3.
Date: Mon, 18 Jun 2012 16:52:31 +0200
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To: Huacai Chen <chenhuacai@gmail.com>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>, Ralf Baechle <ralf@linux-mips.org>, linux-mips@linux-mips.org, Fuxin Zhang <zhangfx@lemote.com>, Zhangjin Wu <wuzhangjin@gmail.com>, Huacai Chen <chenhc@lemote.com>, Hongliang Tao <taohl@lemote.com>, Hua Yan <yanh@lemote.com>, linux-ide@vger.kernel.org

On Mon, Jun 18, 2012 at 06:41:58PM +0800, Huacai Chen wrote:
> Ohh, this is because Loongson-3 has a hardware bug, when the HT
> controller receive a 64-bit DMA address, the high bits is lost. So set
> to 32-bit DMA is just a workaround.

Ok, this should definitely go into the commit message of your patch then
since it explains why you need that flag set.

Thanks.

-- 
Regards/Gruss,
Boris.