On Wed, Mar 23, 2011 at 05:12:05PM +0100, Arnd Bergmann wrote: > On Wednesday 23 March 2011, Greg KH wrote: > > On Wed, Mar 23, 2011 at 11:32:02AM +0100, Arnd Bergmann wrote: > > > On Wednesday 23 March 2011, Andy Green wrote: > > > > It's the case for even usbnet, which is using a broken heuristic to > > > > decide what to call the interface not even based on vid / pid. > > > > > > I agree that the heuristics in usbnet is less than helpful here, > > > which among other things leads people to mixing up the two problems > > > of fixing the device naming and fixing the MAC address assignment. > > > > > > Even though I know Greg disagrees, I'd still prefer sanitising the > > > rules for the default device name that usbnet assigns. > > > > I'm all for that, but recall, we can't because of previous > > implementations and past history. I.e. you will break working systems > > if you do this. So we are stuck with what we have at the moment, sorry. > > I would still consider it a bug fix and argue that the number of actual > people impacted by the current behaviour is much larger than the potential > number people that might suffer from changing the behavior in an incompatible > way, given that: > > * The common case for this hardware seems to be to ship with an eeprom > with a valid mac address, as identified by the fact that f4e8ab7c > "smsc95xx: generate random MAC address once, not every ifup" only recently > got into the kernel as a bug fix for the random case, though the driver > has been around since 2008. > > * A google search on the term "smsc95xx" find almost exclusively discussions > about how to get the device to come up with a proper name on the panda > board, and various proposed workarounds. > > * The comment in usbnet.c about this suggests that the intent has always > been what is proposed now, it just doesn't match the code: > > // heuristic: "usb%d" for links we know are two-host, > // else "eth%d" when there's reasonable doubt. userspace > // can rename the link if it knows better. > if ((dev->driver_info->flags & FLAG_ETHER) != 0 && > (net->dev_addr [0] & 0x02) == 0) > strcpy (net->name, "eth%d"); > > In case of smsc95xx, we *know* that it's ethernet and not two-host, > there is no reasonable doubt about this. The code almost makes sense > on generic cdc devices, but not for anything else. Ok, let's fix it up and see who complains :) thanks, greg k-h -- 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
