Re: [PATCH v2 3/3] arch/*/: remove CONFIG_VIRT_TO_BUS

Michael Schmitz
2022-06-29T00:14:57Z

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