[ 71/82] USB: Prepare for refactoring by adding extra udev checks.

[Ben Hutchings]

3.2-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>

commit 2d4fa940f99663c82ba55b2244638833b388e4e2 upstream.

The next patch will refactor the hub port code to rip out the recursive
call to hub_port_reset on a failed hot reset.  In preparation for that,
make sure all code paths can deal with being called with a NULL udev.
The usb_device will not be valid if warm reset was issued because a port
transitioned to the Inactive or Compliance Mode on a device connect.

This patch should have no effect on current behavior.

Signed-off-by: Sarah Sharp <sarah.a.sharp@xxxxxxxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/usb/core/hub.c |   21 +++++++++++++--------
 1 files changed, 13 insertions(+), 8 deletions(-)

--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2194,6 +2194,9 @@ static int hub_port_wait_reset(struct us
 				return -ENOTCONN;
 
 			if ((portstatus & USB_PORT_STAT_ENABLE)) {
+				if (!udev)
+					return 0;
+
 				if (hub_is_wusb(hub))
 					udev->speed = USB_SPEED_WIRELESS;
 				else if (hub_is_superspeed(hub->hdev))
@@ -2237,13 +2240,15 @@ static void hub_port_finish_reset(struct
 			struct usb_hcd *hcd;
 			/* TRSTRCY = 10 ms; plus some extra */
 			msleep(10 + 40);
-			update_devnum(udev, 0);
-			hcd = bus_to_hcd(udev->bus);
-			/* The xHC may think the device is already reset,
-			 * so ignore the status.
-			 */
-			if (hcd->driver->reset_device)
-				hcd->driver->reset_device(hcd, udev);
+			if (udev) {
+				update_devnum(udev, 0);
+				hcd = bus_to_hcd(udev->bus);
+				/* The xHC may think the device is already
+				 * reset, so ignore the status.
+				 */
+				if (hcd->driver->reset_device)
+					hcd->driver->reset_device(hcd, udev);
+			}
 		}
 		/* FALL THROUGH */
 	case -ENOTCONN:
@@ -2257,7 +2262,7 @@ static void hub_port_finish_reset(struct
 			clear_port_feature(hub->hdev, port1,
 					USB_PORT_FEAT_C_PORT_LINK_STATE);
 		}
-		if (!warm)
+		if (!warm && udev)
 			usb_set_device_state(udev, *status
 					? USB_STATE_NOTATTACHED
 					: USB_STATE_DEFAULT);


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