[PATCH v2] gianfar: Add I/O barriers when touching buffer descriptor ownership.
Scott Wood
scottwood at freescale.com
Thu May 3 06:40:20 EST 2007
Kumar Gala wrote:
> On May 2, 2007, at 3:12 PM, Scott Wood wrote:
>> wmb() is a sync, smp_wmb() is an eieio. Andy told me he would not
>> accept a sync in those spots.
>
>
> Sorry, was looking at the iobarrier code.
>
>> And the driver is already ppc-specific; it uses in/out_be32.
>
>
> True, but its hidden behind the gfar_read/write accessors.
>
> Your change is a bit more blatant.
Well, Segher doesn't want me to use iobarrier (because it's not I/O).
Andy doesn't want me to use wmb() (because it's sync). I don't think
something like gfar_wmb() would be appropriate. So the remaining
options are either eieio(), or a new non-arch-specific,
non-driver-specific mem_wmb() (or whatever).
While I like the latter option, I don't think this bugfix should have to
wait for it.
-Scott
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