On Mon, Sep 23, 2013 at 05:23:07PM -0700, Sarah Sharp wrote: > On Mon, Sep 23, 2013 at 02:49:07PM -0700, Greg KH wrote: > > On Mon, Sep 23, 2013 at 04:38:22PM -0500, Bjorn Helgaas wrote: > > > On Mon, Sep 23, 2013 at 3:49 PM, Greg KH <greg@xxxxxxxxx> wrote: > > > > On Mon, Sep 23, 2013 at 09:06:54PM +0300, Xenia Ragiadakou wrote: > > > >> I had in mind that the pci_ops .read and .write defined by the PCI > > > >> driver will take care of consistent byteorder access to the > > > >> configuration registers. At least, that was what i understood after > > > >> reading the > > > >> chapter on PCI of Linux Device Drivers (more specifically for > > > >> pci_write_config_* functions, it states that "The word and dword > > > >> functions convert the value to little-endian before writing to the > > > >> peripheral device."). > > > > > > > > Hm, I wrote that paragraph (or at least I think I did), but I sure > > > > didn't remember this at all... > > > > > > > > Hm, wait, I do see this happening for the PowerPC cell PCI code, so it > > > > might happen somewhere burried in the platform-specific code for > > > > different arches. You will not see it happen on x86 as there's no need > > > > to swap any bytes around. > > > > > > Greg, with regard to Xenia's patch, is this an ack or a nack? Since > > > you didn't include an "Acked-by" line, I assume you think Xenia's > > > patch is unnecessary. In that case, is there any way to shut sparse > > > up so it doesn't complain about this? > > > > At this point in time, I don't remember what the original patch looked > > like, and as it's an xhci patch, Sarah needs to ack it, not me :) > > Greg: So you're saying that there isn't a need to convert values from > CPU byte-ordering to little endian byte-ordering before passing them on > to pci_write_config_*? That is correct. Xenia, thanks for figuring this out, nice job. greg k-h -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
