On Wed, 24 Oct 2012, Mitch Bradley wrote: > >> Ah, now I'm starting to get the picture. > >> > >> 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. Unfortunately that's not saying very much. The EHCI spec describes only PCI-based controllers. Every other sort does require something extra. > 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. While I haven't checked in detail, it seems quite likely that this would not work with some of the devices that have "usb-ehci" listed in their compatible values. Alan Stern -- 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
