Re: [openib-general] Re: [PATCH 53 of 53] ipath - add memory barrier when waiting for writes

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



>     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.

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux