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Message-ID: <1492005205.7236.63.camel@kernel.crashing.org>
Subject: Re: EEH error in doing DMA with PEX 8619
From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: IanJiang <ianjiang.cn@gmail.com>, linuxppc-dev@ozlabs.org
Date: Wed, 12 Apr 2017 23:53:25 +1000
In-Reply-To: <CAFE2VE+pm=bBVBx3Ws08kcKGhZO+BaxJcmskjg4DFjNKHQj-9w@mail.gmail.com>
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On Wed, 2017-04-12 at 01:42 -0700, IanJiang wrote:
> 
> In my test, DMA buffers are allocated with  (bus 2, device 1, function 
> 0) in module Plx8000_NT, but DMA is issued by (bus 1 device 0 function 
> 1) in module Plx8000_DMA. And error of (bus 1 device 0 function 1) is 
> reported by EEH. 

This is going to break on other systems too. If you enable strict iommu
on x86 for example.

You need to ensure that DMA are allocated for the same requester ID
that will be performing the transactions.

Cheers,
Ben.