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SubjectRe: [openib-general] Re: [PATCH 53 of 53] ipath - add memory barrier when waiting for writes
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>     ralphc> We had a power failure here so I'm not able to reproduce
> ralphc> the assembly code at the moment. What I remember from
> ralphc> looking at the code is that the code for
> ralphc> ipath_read_kreg32() was present in i2c_wait_for_writes()
> ralphc> when compiled -Os so it didn't look like a compiler bug.
> ralphc> I probably could put the mb() at the end of i2c_gpio_set()
> ralphc> if that makes you more comfortable. The mb() is
> ralphc> definitely needed though.
>
> Is it the mb()? Or is just a barrier() enough? In other words do you
> really need the mfence, or do you just need to stop the compiler from
> reordering things?
>
> - R.

I didn't try calling barrier() so I don't know the answer.
When power is restored, I can try it.
My guess is that it's a timing issue and not a code reordering
issue.

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