On 9/17/07, Jiri Slaby <jirislaby@xxxxxxxxx> wrote: > On 09/17/2007 10:59 PM, Jeff Garzik wrote: > > Jiri Slaby wrote: > >> NACK, this is wrong. iomap returns platform dependant return value, > >> which may or > > > > Incorrect. readl() and writel() work just fine on all existing > > platforms where Atheros may be used. > > Ok, this is what Alan Cox wrote about that and you didn't reply to it, so I > thought he's right. Anyway I wouldn't rely on iomap that it will never be > changed even on x86 -- what's the (performance) impact of having ioread instead > of readl? How much data are transferred this way? > > <cite from="http://lkml.org/lkml/2007/8/25/50";> > On Sat, 25 Aug 2007 04:56:19 -0400 > Jeff Garzik <jgarzik@xxxxxxxxx> wrote: > > > If the driver knows its MMIO, using readX/writeX after pci_iomap() is > > just fine, for all current implementations, and it makes sense that way. > > There is nothing that guarantees this is permitted, any more than there > is anything saying not to use outb/outl. Some of the implementations do > quite strange things. It may happen to work but its not in the > documentation or the comments. I posted a patch to update the documentation with this. > Please, can anybody clarify it? Based on Alan's 'Review-by' remarks on my patch for updating the documenation on pci_iomap() it seems this validates this patch. Please see thread with subject: [PATCH] Clarify pci_iomap() usage for MMIO-only devices Luis - 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
