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authorLuben Tuikov <ltuikov@yahoo.com>2011-02-11 11:33:10 -0800
committerGreg Kroah-Hartman <gregkh@suse.de>2011-03-07 15:05:14 -0800
commit8adc60863e6f85a50212d0b8623c38fdb7e5d4c7 (patch)
tree8f60a3cad159f568745a963b3897720cf444614b
parent929364a96776f45edc9b1d71680bf87852dfc39b (diff)
USB: Reset USB 3.0 devices on (re)discovery
commit 07194ab7be63a972096309ab0ea747df455c6a20 upstream. 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. Note from Sarah Sharp: This patch should be queued for stable trees all the way back to 2.6.34, since that was the first kernel that supported configured device reset. The code this patch touches has been there since 2.6.32, but the bug would never be hit before 2.6.34 because the xHCI driver would completely reject an attempt to reset a configured device under xHCI. Signed-off-by: Luben Tuikov <ltuikov@yahoo.com> Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/core/hub.c18
1 files changed, 7 insertions, 11 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 32d0ad29e23a..01aa2447241f 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2672,17 +2672,13 @@ 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) {