Re: [linux-usb-devel] Re: serious 2.6 bug in USB subsystem?

From: David Mosberger
Date: Mon Nov 03 2003 - 16:26:42 EST

>>>>> On Sun, 02 Nov 2003 19:46:38 -0800, David Brownell <david-b@xxxxxxxxxxx> said:

David> I'm not sure that if the HID driver were to pass a null
David> buffer pointer, it would be caught anywhere.
>> OK, I'll try to find some time to trace the I/O MMU calls to see
>> if something isn't kosher at that level. Is there a good way of
>> getting a relatively high-level of tracing in the USB subsystem
>> that would some me what's going on between the HID and the core
>> USB level?

Dave.B> Most of that story is just submitting and completing URBs.

Yeah. And it appears that it's the very first call to
hid_submit_ctrl() that's triggering the problem (not always, but about
9 out of 10 times). I dumped some of the key fields for the URB being
submitted and they all looked saned to me.

Dave.B> I'd either try changing the spots in drivers/usb/core/hcd.c
Dave.B> marked as appropriate for generic MONITOR_URB hooks (printk
Dave.B> if it's your HID device, maybe), or manually turn on
Dave.B> whatever HCD-specific hooks exist (maybe use a VERBOSE
Dave.B> message level).

OK, thanks for the suggestion. I'll keep looking, but will be on
travel this week, so I may not be able to spend much time on this

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