[PATCH] usbip:vhci_hcd USB port can get stuck in the disabled state

[PATCH] usbip:vhci_hcd USB port can get stuck in the disabled state

[Shuah Khan]

When a remote usb device is attached to the local Virtual USB
Host Controller Root Hub port, the bound device driver may send
a port reset command.

vhci_hcd accepts port resets only when the device doesn't have
port address assigned to it. When reset happens device is in
assigned/used state and vhci_hcd rejects it leaving the port in
a stuck state.

This problem was found when a blue-tooth or xbox wireless dongle
was passed through using usbip.

A few drivers reset the port during probe including mt76 driver
specific to this bug report. Fix the problem with a change to
honor reset requests when device is in used state (VDEV_ST_USED).

Suggested-by: Michael <msbroadf@gmail.com>
Reported-and-tested-by: Michael <msbroadf@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
 drivers/usb/usbip/vhci_hcd.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c
index 4ba6bcdaa8e9..937f28f3d579 100644
--- a/drivers/usb/usbip/vhci_hcd.c
+++ b/drivers/usb/usbip/vhci_hcd.c
@@ -455,8 +455,14 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 			vhci_hcd->port_status[rhport] &= ~(1 << USB_PORT_FEAT_RESET);
 			vhci_hcd->re_timeout = 0;
 
+			/*
+			 * A few drivers do usb reset during probe when
+			 * the device could be in VDEV_ST_USED state
+			 */
 			if (vhci_hcd->vdev[rhport].ud.status ==
-			    VDEV_ST_NOTASSIGNED) {
+				VDEV_ST_NOTASSIGNED ||
+			    vhci_hcd->vdev[rhport].ud.status ==
+				VDEV_ST_USED) {
 				usbip_dbg_vhci_rh(
 					" enable rhport %d (status %u)\n",
 					rhport,
-- 
2.30.2