[PATCH v2 1/3] ARM: Introduce *_relaxed() I/O accessors

Jamie Lokier jamie at shareable.org
Mon Jul 12 07:50:35 EDT 2010

Arnd Bergmann wrote:
> Ah, that's right: writel and outl both need the barrier before the access,
> but writel will never need a barrier after the access.
> The x86 variant of outl also has the implicit ordering after the access,
> but I'm not sure if we need to emulate that. I can't currently think
> of a case where it's strictly required because any later access to the same
> PCI function will be ordered anyway.

What about those ARMs which can buffer a write for an indefinite period?
Do any drivers expect writes to be posted in a reasonably short time?

-- Jamie

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