Hi Alan, I have a few questions about gadgetfs.
According to documentation usb_gadget_driver->setup "queues a response to ep0, or returns negative to stall". Do I understand correctly, that "stall" in this case means "retry the same request later" and it's unrelated to the STALL USB packet? Is it OK to stall the initial control requests (the one that requests the device descriptor for example)? What exactly happens when we stall between the gadget and the host? Does the UDC driver/hardware see that we don't have a response yet and waits? Or does it somehow communicate that stall to the host? Does it make any difference whether we stall or reply right away from the host point of view? The questions arose when I started implementing a gadgetfs like interface, that allows to respond to every USB packet (including the initial control requests) from a userspace app. Thanks!
