On 02/01/12 20:48, Linus Torvalds wrote: > On Mon, Jan 2, 2012 at 12:41 PM, Jack Stone <jwjstone@xxxxxxxxxxx> wrote: >> >> What about the case where the firmware that needs to be loaded is on the >> USB device that needs the firmware. This can be resolved at boot using >> an initrd but at resume time we don't have that. > > Quite frankly, caching the firmware will just automagically fix this. > > I don't understand why people even bother to talk about USB ID's etc > changing - that is totally irrelevant. We don't look up firmware by > USB ID's anyway. I agree. The only problem I can see is with the lifetime of the firmware. If we have a generic USB driver that looks after (for example) all USB disks then we do not want to add the knowedge to it for each individual vendors firmware. For example: 1/ Plug in device, registers as a bootstrap device 2/ Load firmware into device (and put firmware in cache) 3/ Device disconnects and reconnects with new USB id 4/ Generic driver takes over as it recognizes the new id The problem comes with knowing when to put the firmware - how do we tell the generic driver that that device has firmware that might need to be freed on disconnect. I don't know enough about USB to know if we can tell if the same device has reconnected due to firmware being loaded or if it was simply unplugged and a new device plugged in. Hope this makes sense, Jack -- 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
