On Wed, Oct 24, 2012 at 08:55:27AM -1000, Mitch Bradley wrote: > >> So by listing "usb-ehci" in its device ID table, a driver would > >> essentially be saying that it can handle _all_ USB EHCI controllers. > > > Actually, it means that the driver can handle at least USB EHCI > controllers that are 100% compatible with the EHCI spec (requiring > nothing extra). The driver might be able to handle almost-compatible > controllers, possibly with the help of additional properties. > > If a DT node lists "usb-ehci" as a "fallback", it's not guaranteed that > a given version of that driver will work, but it's worth a try in the > event that no more-specific driver is matched. Not sure fallback is a good term here. The of parses the compatible from left to right. If the device specific entry is not found (in the driver) then end up with usb-ehci. If we need a quirk later on we add the device specific entry to the driver (which will match before usb-ehci is found) and we could use this entry to apply the quirk. That way you can apply quirks without touch the firmware / device tree. Sebastian -- 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
