On Tue, 2015-01-27 at 21:39 -0800, Peter Oh wrote: > > Ok, sure, but I/O ordering two different writes, and ensuring device > > has seen a posted write, are related but different things, no? > yes, they are different and wmb guarantees both. No, wmb() doesn't. I'd be very surprised if it had any side effect on the PCI bus even on ARM. Read Documentation/memory-barriers.txt. And to understand (PCI) posted writes, wikipedia helps: http://en.wikipedia.org/wiki/Posted_write johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html