Re: 2.6.36-rc7: NULL pointer dereference in ehci_clear_tt_buffer_complete

From: Stefan Richter
Date: Sat Oct 16 2010 - 16:35:36 EST


Alan Stern wrote:
> On Sat, 16 Oct 2010, Stefan Richter wrote:
>> Alan Stern wrote:
>>> --- usb-2.6.orig/drivers/usb/core/message.c
>>> +++ usb-2.6/drivers/usb/core/message.c
>>> @@ -323,8 +323,13 @@ static void sg_complete(struct urb *urb)
>>> /* on the last completion, signal usb_sg_wait() */
>>> io->bytes += urb->actual_length;
>>> io->count--;
>>> - if (!io->count)
>>> + if (!io->count) {
>>> + if (status == -ECONNRESET) {
>>> + printk(KERN_ERR "Delaying for test\n");
>>> + mdelay(600);
>>> + }
>>> complete(&io->complete);
>>> + }
>>>
>>> spin_unlock(&io->lock);
>>> }
>>>
>> I did so today on 2.6.36-rc8, without your other patch. I was still unable to
>> reproduce the bug. Forget the whole thing as unreproducible?
>
> What I said above wasn't quite right. This won't help trigger the
> oops, but it should trigger the line saying something like
>
> ehci_hcd 0000:00:12.2: qh ffff880208f07af0 (#00) state 5
>
> That's the real bug.

# grep ' qh ' /var/log/messages
Oct 11 22:29:21 stein kernel: ehci_hcd 0000:00:12.2: qh ffff880208f07af0 (#00)
state 5

I.e. there was none anymore since the one which I reported on Monday.
--
Stefan Richter
-=====-==-=- =-=- =----
http://arcgraph.de/sr/
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