On Sat, 27 Feb 2010 11:59:47 -0600 Robert Hancock <hancockrwd@xxxxxxxxx> wrote: > On Sat, Feb 27, 2010 at 3:53 AM, David Miller <davem@xxxxxxxxxxxxx> wrote: > > From: Robert Hancock <hancockrwd@xxxxxxxxx> > > Date: Fri, 26 Feb 2010 21:08:04 -0600 > > > >> That seems like a reasonable approach to me. Only question is how to > >> implement the check for DMA_64BIT. Can we just check page_to_phys on > >> each of the pages in the skb to see if it's > 0xffffffff ? Are there > >> any architectures where it's more complicated than that? > > > > On almost every platform it's "more complicated than that". > > > > This is the whole issue. What matters is the final DMA address and > > since we have IOMMUs and the like, it is absolutely not tenable to > > solve this by checking physical address attributes. > > Yeah, physical address isn't quite right. There is a precedent for Probably, you need to check PCI_DMA_BUS_IS_PHYS. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
