[ewg] Re: [PATCH 2/14] nes: device structures and defines
jeff at garzik.org
Wed Aug 8 09:59:08 PDT 2007
Michael Buesch wrote:
> writel doesn't guarantee flushing either.
> readl does.
Not quite -- there are multiple kinds of flushing. You're thinking
about flushing across PCI bridges, which is correct, but you also have
CPU write posting and CPU write ordering and such.
Without taking all that into account, you might be tempted to think that
__raw_readl() will perform all flushes necessary following a
__raw_writel() -- but that would be incorrect.
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