Resend because sent to maillist failed. 2012/7/19 Oliver Neukum <[email protected]> > > 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.
Oh. I recheck find these device will use ordinary resume rather than reset_resume(). I remeber you said userspace should set USB_QUIRK_RESET_MORPHS for those kind devices. After reset, they will morph. So reset_resume doesn't work for them. Ordinary resume almost just calls usb_get_status(udev, USB_RECIP_DEVICE, 0, &devstatus) to verify whether usb device is OK. So even the device has been repowered. Resume will be sucessful even the interface is changed. So I have idea to add a verify_resume without reset for these kind devices. Check whether device class was changed or interface vanish .If it morphed, then return error and then renumerate then. Does this make sense? > > > > The driver loaded again with firmware and the device still could work, is > > Right? > > No. All settings user space has done will be lost. Can we notify user space to reconfigue it? Or they will find original device have removed and new device is coming. Reconfigue the new device. Because the device is renumerated during this procedure. -- Best regards Lan Tianyu -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
