Am Sonntag, 1. Januar 2012, 21:30:04 schrieb Linus Torvalds: > Suspend/resume is *special*, and it's special for a very simple > reason: unlike bootup or attaching a new device, suspend/resume > happens WHILE THE USER IS ACTIVE. > > Loading firmware at that time is wrong. It's impossible. You have to > have the firmware available *before* any processes might need it, but > at the same time actually loading the firmware may need help from user > space and/or other devices. It's a chicken-and-egg problem. > > So let me repeat one more time: Loading firmware at resume time is a > device driver bug. Seriously. How many times do I have to say it? We accept that. And if everything goes well, we keep that rule. The problem we are seeing here is a problem in USB's error handling. It happens as we already have decided that we are unable to properly resume the device. Ideally usbcore would deal with such devices, but at present the USB layer is unable to cleanly resume devices that change their IDs during resume. Solving this would mean putting all firmware loaders into kernel space. And the mode switching logic as well. But IMHO resuming a device can always fail, as it involves actual IO, so we need a functional error handling at that point. Regards Oliver -- 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
