On 22.10.2012 17:17, Alan Stern wrote:
> On Sun, 21 Oct 2012, Artem S. Tashkinov wrote:
>
>> dmesg messages up to a crash can be seen here:
>> https://bugzilla.kernel.org/attachment.cgi?id=84221
>
> The first problem in the log is endpoint list corruption. Here's a
> debugging patch which should provide a little more information.
Maybe add a BUG() after each of these dev_err() so we stop at the first
occurance and also see where we're coming from?
> drivers/usb/core/hcd.c | 36 ++++++++++++++++++++++++++++++++++++
> 1 file changed, 36 insertions(+)
>
> Index: usb-3.6/drivers/usb/core/hcd.c
> ===================================================================
> --- usb-3.6.orig/drivers/usb/core/hcd.c
> +++ usb-3.6/drivers/usb/core/hcd.c
> @@ -1083,6 +1083,8 @@ EXPORT_SYMBOL_GPL(usb_calc_bus_time);
>
> /*-------------------------------------------------------------------------*/
>
> +static bool list_error;
> +
> /**
> * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
> * @hcd: host controller to which @urb was submitted
> @@ -1126,6 +1128,20 @@ int usb_hcd_link_urb_to_ep(struct usb_hc
> */
> if (HCD_RH_RUNNING(hcd)) {
> urb->unlinked = 0;
> +
> + {
> + struct list_head *cur = &urb->ep->urb_list;
> + struct list_head *prev = cur->prev;
> +
> + if (prev->next != cur && !list_error) {
> + list_error = true;
> + dev_err(&urb->dev->dev,
> + "ep %x list add corruption: %p %p %p\n",
> + urb->ep->desc.bEndpointAddress,
> + cur, prev, prev->next);
> + }
> + }
> +
> list_add_tail(&urb->urb_list, &urb->ep->urb_list);
> } else {
> rc = -ESHUTDOWN;
> @@ -1193,6 +1209,26 @@ void usb_hcd_unlink_urb_from_ep(struct u
> {
> /* clear all state linking urb to this dev (and hcd) */
> spin_lock(&hcd_urb_list_lock);
> + {
> + struct list_head *cur = &urb->urb_list;
> + struct list_head *prev = cur->prev;
> + struct list_head *next = cur->next;
> +
> + if (prev->next != cur && !list_error) {
> + list_error = true;
> + dev_err(&urb->dev->dev,
> + "ep %x list del corruption prev: %p %p %p\n",
> + urb->ep->desc.bEndpointAddress,
> + cur, prev, prev->next);
> + }
> + if (next->prev != cur && !list_error) {
> + list_error = true;
> + dev_err(&urb->dev->dev,
> + "ep %x list del corruption next: %p %p %p\n",
> + urb->ep->desc.bEndpointAddress,
> + cur, next, next->prev);
> + }
> + }
> list_del_init(&urb->urb_list);
> spin_unlock(&hcd_urb_list_lock);
> }
>
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