On Thu, Jul 19, 2012 at 5:33 PM, Oliver Neukum <oneukum@xxxxxxx> wrote: > On Thursday 19 July 2012 16:21:38 Lan Tianyu wrote: >> On 2012年07月19日 14:37, Oliver Neukum wrote: > >> > Unloading the driver is a user space issue. >> > But you are right there is a missing case >> hi all: >> I have a question About device which needs a firmware when connected. >> If the port powered off when it was suspend, the port would power on >> when system try to access the device. What happen if try to resume the device, >> guess it will fail. usb core would disconnect the device and renumerate the device. > > Yes. That's how reset_resume() works. If reset_resume flag is set, usbcore will try to reset the device first during resume, and no disconnect will be involved if reset completes successfully. > >> The driver loaded again with firmware and the device still could work, is Right? > > No. All settings user space has done will be lost. > >> I have no a such device to do test. Just from guess. The point is whether >> resuming the device without loading firmware will fail. > > It must. Interfaces can vanish and the device class can change. > There's nothing to remain bound to. If only interfaces may vanish, how about store the user setting things inside usb_device instance of the interfaces? Thanks, -- Ming Lei -- 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
