[PATCH] cleanup after dead hc needs task context

Simple patch to invoke hcd->stop() in task context, as
required.  When Cardbus works again (broken in 2.5.53
unless it's just me), this will get rid of some oopsing
when folk physically eject the device, with no shutdown.
As well as making other "hc died" faults behave better.

drivers/usb/core/hcd.c

@@ -1339,6 +1339,12 @@ EXPORT_SYMBOL (usb_hcd_irq);
 
 /*-------------------------------------------------------------------------*/
 
+static void hcd_panic (void *_hcd)
+{
+	struct usb_hcd *hcd = _hcd;
+	hcd->driver->stop (hcd);
+}
+
 /**
  * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
  * @hcd: pointer to the HCD representing the controller
@@ -1371,9 +1377,9 @@ void usb_hc_died (struct usb_hcd *hcd)
 		urb->status = -ESHUTDOWN;
 	spin_unlock_irqrestore (&hcd_data_lock, flags);
 
-	if (urb)
-		usb_rh_status_dequeue (hcd, urb);
-	hcd->driver->stop (hcd);
+	/* hcd->stop() needs a task context */
+	INIT_WORK (&hcd->work, hcd_panic, hcd);
+	(void) schedule_work (&hcd->work);
 }
 EXPORT_SYMBOL (usb_hc_died);
 

drivers/usb/core/hcd.h

@@ -67,6 +67,7 @@ struct usb_hcd {	/* usb_bus.hcpriv points to this */
 
 	struct timer_list	rh_timer;	/* drives root hub */
 	struct list_head	dev_list;	/* devices on this bus */
+	struct work_struct	work;
 
 	/*
 	 * hardware info/state