提交 637d11bf 编写于 作者: L Luben Tuikov 提交者: Greg Kroah-Hartman

USB: Reset USB 3.0 devices on (re)discovery

If the device isn't reset, the XHCI HCD sends
SET ADDRESS to address 0 while the device is
already in Addressed state, and the request is
dropped on the floor as it is addressed to the
default address. This sequence of events, which this
patch fixes looks like this:

usb_reset_and_verify_device()
	hub_port_init()
		hub_set_address()
			SET_ADDRESS to 0 with 1
		usb_get_device_descriptor(udev, 8)
		usb_get_device_descriptor(udev, 18)
	descriptors_changed() --> goto re_enumerate:
		hub_port_logical_disconnect()
			kick_khubd()

And then:

hub_events()
	hub_port_connect_change()
		usb_disconnect()
			usb_disable_device()
		new device struct
		sets device state to Powered
		choose_address()
		hub_port_init() <-- no reset, but SET ADDRESS to 0 with 1, timeout!

The solution is to always reset the device in
hub_port_init() to put it in a known state.
Signed-off-by: NLuben Tuikov <ltuikov@yahoo.com>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
上级 72a012ce
......@@ -2681,17 +2681,13 @@ hub_port_init (struct usb_hub *hub, struct usb_device *udev, int port1,
mutex_lock(&usb_address0_mutex);
if (!udev->config && oldspeed == USB_SPEED_SUPER) {
/* Don't reset USB 3.0 devices during an initial setup */
usb_set_device_state(udev, USB_STATE_DEFAULT);
} else {
/* Reset the device; full speed may morph to high speed */
/* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
retval = hub_port_reset(hub, port1, udev, delay);
if (retval < 0) /* error or disconnect */
goto fail;
/* success, speed is known */
}
/* Reset the device; full speed may morph to high speed */
/* FIXME a USB 2.0 device may morph into SuperSpeed on reset. */
retval = hub_port_reset(hub, port1, udev, delay);
if (retval < 0) /* error or disconnect */
goto fail;
/* success, speed is known */
retval = -ENODEV;
if (oldspeed != USB_SPEED_UNKNOWN && oldspeed != udev->speed) {
......
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