On Wednesday 08 August 2007 18:33:24 Jeff Garzik wrote: > Michael Buesch wrote: > > On Wednesday 08 August 2007 18:18:31 Roland Dreier wrote: > >> > But there are indeed a few cases that look wrong. > >> > >> yes... > >> > >> > arch/x86_64/kernel/pci-calgary.c: writel(cpu_to_be32(val), > >> target); > >> > >> eg this almost certainly wants to be > >> > >> writel(swab32(val), target); > >> > >> or something equivalent like > >> > >> __raw_writel(cpu_to_be32(val), target); > >> /* plus some suffficent memory ordering */ > >> > >> - R. > >> > >> > > > > certainly, yes. > > Most likely the __raw_writel variant is portable, but I am not > > sure. Anybody sure? > > Yes, it's portable. You must however be aware of the guarantees that > writel() provides and __raw_writel() does not: no barriers or flushes, > no endian conversions, no ordering constraints, ... Probably a few more > details I'm forgetting too :)
writel doesn't guarantee flushing either. readl does. The barrier/ordering issue however might be a critical thing, when using __raw_XXX. So one must always mmiowb() after such a write. -- Greetings Michael. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
