Re: [BUG] usb/core/hub.c loops forever on resume from ram due to bluetooth

Mark Lord
2007-05-14T23:48:16Z

Greg KH wrote:
>
> Ok, I'll take a patch to keep the loop from going forever, but the main
> issue here is that there is probably a hardware failure somewhere.

Okay, found it. The root cause here was a missing CONFIG_USB_SUSPEND=y,
which means the hci_usb device never got marked as USB_STATE_SUSPENDED,
which then caused the loop to go on forever.

The system works fine now with CONFIG_USB_SUSPEND=y in the .config.

Here's the patch to prevent future lockups for this or other causes.
I no longer need it, but it does still seem a good idea.

Signed-off-by: Mark Lord <mlord@pobox.com>
---

--- old/drivers/usb/core/hub.c 2007-04-26 12:02:47.000000000 -0400
+++ linux/drivers/usb/core/hub.c 2007-05-01 18:48:46.000000000 -0400
@@ -403,9 +403,10 @@
struct usb_hub *hub =
container_of(work, struct usb_hub, tt.kevent);
unsigned long flags;
+ int limit = 100;

spin_lock_irqsave (&hub->tt.lock, flags);
- while (!list_empty (&hub->tt.clear_list)) {
+ while (--limit && !list_empty (&hub->tt.clear_list)) {
struct list_head *temp;
struct usb_tt_clear *clear;
struct usb_device *hdev = hub->hdev;