Commit 1b42ae6d authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman

USB: fix race in HCD removal

This patch (as865) fixes a race in the HCD removal code discovered by
Milan Plzik.  Arrival of an interrupt after the root hub was
unregistered could cause the root-hub status timer to start up, even
after it was supposed to have been shut down.  The problem is fixed by
moving the del_timer_sync() call to after the HCD's stop() method, at
which time IRQ generation should be disabled.

Cc: Milan Plzik <milan.plzik@gmail.com>
Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 949be0f7
......@@ -544,6 +544,8 @@ void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
unsigned long flags;
char buffer[4]; /* Any root hubs with > 31 ports? */
if (unlikely(!hcd->rh_registered))
return;
if (!hcd->uses_new_polling && !hcd->status_urb)
return;
......@@ -1670,12 +1672,12 @@ void usb_remove_hcd(struct usb_hcd *hcd)
usb_disconnect(&hcd->self.root_hub);
mutex_unlock(&usb_bus_list_lock);
hcd->poll_rh = 0;
del_timer_sync(&hcd->rh_timer);
hcd->driver->stop(hcd);
hcd->state = HC_STATE_HALT;
hcd->poll_rh = 0;
del_timer_sync(&hcd->rh_timer);
if (hcd->irq >= 0)
free_irq(hcd->irq, hcd);
usb_deregister_bus(&hcd->self);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment