[linux-usb-devel] [patch 2.6.0-test3] usb hc cleanup-after-death, oops fix

[David Brownell]

Recently we've seen some oopses reported in code that cleaned
up HCs after they died ... like pci-pm not letting ohci-hcd
suspend until after the hardware was partly disabled, or users
removing a Cardbus adapter with ehci-hcd.  One root cause was
that the cleanup called hcd->stop() too many times.
This patch just does the cleanup that's reasonable to do
before the (dead) root hub is cleaned up:  it disconnects
the other devices.  And based on a suggestion from Pavel,
a diagnostic always appears -- avoiding mystery.
Please merge for test4; thanks in advance!

- Dave

--- 1.71/drivers/usb/core/hcd.c Tue Aug  5 09:46:38 2003
+++ edited/drivers/usb/core/hcd.c       Tue Aug 12 16:07:44 2003
@@ -1494,8 +1494,16 @@
 
 static void hcd_panic (void *_hcd)
 {
-       struct usb_hcd *hcd = _hcd;
-       hcd->driver->stop (hcd);
+       struct usb_hcd          *hcd = _hcd;
+       struct usb_device       *hub = hcd->self.root_hub;
+       unsigned                i;
+
+       /* hc's root hub is removed later removed in hcd->stop() */
+       hub->state = USB_STATE_NOTATTACHED;
+       for (i = 0; i < hub->maxchild; i++) {
+               if (hub->children [i])
+                       usb_disconnect (&hub->children [i]);
+       }
 }
 
 /**
@@ -1508,29 +1516,9 @@
  */
 void usb_hc_died (struct usb_hcd *hcd)
 {
-       struct list_head        *devlist, *urblist;
-       struct hcd_dev          *dev;
-       struct urb              *urb;
-       unsigned long           flags;
-       
-       /* flag every pending urb as done */
-       spin_lock_irqsave (&hcd_data_lock, flags);
-       list_for_each (devlist, &hcd->dev_list) {
-               dev = list_entry (devlist, struct hcd_dev, dev_list);
-               list_for_each (urblist, &dev->urb_list) {
-                       urb = list_entry (urblist, struct urb, urb_list);
-                       dev_dbg (hcd->controller, "shutdown %s urb %p pipe %x, current 
status %d\n",
-                               hcd->self.bus_name, urb, urb->pipe, urb->status);
-                       if (urb->status == -EINPROGRESS)
-                               urb->status = -ESHUTDOWN;
-               }
-       }
-       urb = (struct urb *) hcd->rh_timer.data;
-       if (urb)
-               urb->status = -ESHUTDOWN;
-       spin_unlock_irqrestore (&hcd_data_lock, flags);
+       dev_err (hcd->controller, "HC died; cleaning up\n");
 
-       /* hcd->stop() needs a task context */
+       /* clean up old urbs and devices; needs a task context */
        INIT_WORK (&hcd->work, hcd_panic, hcd);
        (void) schedule_work (&hcd->work);
 }