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Date:   Wed, 29 Jun 2022 12:14:42 +1200
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Subject: Re: [PATCH v2 3/3] arch/*/: remove CONFIG_VIRT_TO_BUS
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From:   Michael Schmitz <schmitzmic@gmail.com>
To:     Bart Van Assche <bvanassche@acm.org>,
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Hi Bart,

On 29/06/22 12:01, Michael Schmitz wrote:
>
>> An example of a user space application that passes an SG I/O data 
>> buffer to the kernel that is aligned to a four byte boundary but not 
>> to an eight byte boundary if the -s (scattered) command line option 
>> is used: 
>> https://github.com/osandov/blktests/blob/master/src/discontiguous-io.cpp
>
> Thanks - four byte alignment actually wouldn't be an issue for me. 
> It's two byte or smaller that would trip up the SCSI DMA.
>
> While I'm sure such an even more pathological test case could be 
> written, I was rather worried about st.c and sr.c input ...
Nevermind - I just see m68k defines ARCH_DMA_MINALIGN to be four bytes. 
Should be safe for all that matters, then.

Cheers,

     Michael