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SubjectRe: DAC960 in 2.5.38, with new changes
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   From: David Mosberger <davidm@napali.hpl.hp.com>
Date: Mon, 23 Sep 2002 13:53:13 -0700

> Or perhaps every platform should provide a writeq(), on 32-bit systems
> it may merely be implemented as two consequetive writel() calls.

True, but I was wondering whether driver writers will have an implicit
assumption on readX/writeX being atomic. I don't think anyone ever
promised that, but I suspect all existing implementations are indeed
atomic (it's true even for old Alphas which don't have sub-word
load/stores).

On many platforms, two consequetive __raw_writel()'s might even
combine to an atomic 64-bit store to PCI space. :-)

I don't think the proposed 32-bit behavior is off the mark, and
anyways x86 can actually make the 64-bit store I believe if it
wants at least on more recent processors.
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