Hi,

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On my AthlonXP single CPU laptop I experience random lockups when I 
access the external USB harddrive with kernels >2.6.23. The problem 
doesn't appear with 2.6.23.

Debugging revealed that a routine was called twice that takes a 
spinlock. But this actually shouldn't happen, because the function 
should only be invoked with interrupts disabled. A little more debugging 
revealed that apparently sometimes interrupts are enabled when the USB 
HCD interrupt handlers are called, although they are registered with 
IRQF_DISABLED.

With the attached patch ontop of 2.6.26-rc8 I get these messages:

kernel: USB_HCD_IRQ interrupts disabled 14206 enabled 6289
kernel: USB_HCD_IRQ interrupts disabled 14761 enabled 6290
kernel: USB_HCD_IRQ interrupts disabled 14761 enabled 6291

I also attached the contents from /proc/interrupts from the machine.

Any ideas what could be wrong or any suggestions in which direction I 
should continue debugging?

Regards,

	Stefan

---
Stefan Becker   Nokia-TP/Salo            Senior Specialist, EE SW
E-Mail: Stefan.Becker@nokia.com          SMS: 4871554@???.??
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