Chipidea USB device goes infinite loop due to interrupt while hw_ep_prime

Hi.

We found an infinite loop inside the function hw_ep_set_halt
(drivers/usb/chipidea/udc.c) if a cablle is repeatedly
connnected/disconnected while ping through RNDIS with chipidea USB
device.

Using ftrace tracing, we found that hw_ep_set_halt is called due to
error return of hw_ep_prime(drivers/usb/chipidea/udc.c:202) which is
called from isr_tr_complete_handler -> isr_setup_status_phase ->
_ep_queue.

The comment of function hw_ep_prime says (execute without
interruption) but timer interrupt is occurred while hw_ep_prime is
executing. We believe that the interrupt causes an error return of
hw_ep_prime. We tried to protect hw_ep_prime from irqs and then no
case of the infinite loop is occurred.

I want ask if it is appropriate way that turning off irq inside
(threaded) irq handlers. And should we explicitly turn off irqs before
calling hw_ep_prime?

Thanks.

-- 
황재호, Jay Hwang, linux team manager of RTst
010-7242-1593