On Fri, Apr 25, 2014 at 01:36:25PM +0000, David Laight wrote: > From: Johan Hovold > > During firmware download the device expects memory addresses in > > big-endian byte order. As the wIndex parameter which hold the address is > > sent in little-endian byte order regardless of host byte order, we need > > to use swab16 rather than cpu_to_be16. > > That doesn't sound correct. > If the value needs to be little-endian, shouldn't you be using > cpu_to_le16() ? It needs to be *big-endian*, otherwise you got it right. > If there is a second cpu_to_be16() being done later on then > the code might be right, but the comments are misleading. There's a second *cpu_to_le16* in usb_ctrl_msg which makes sure that the wIndex parameter is sent little-endian. So in order to transfer a big-endian address using wIndex, we must use swab16 rather than cpu_to_be16 on the address (as the latter is a noop on a big-endian system). Johan -- 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
