Felipe W Damasio wrote:

>     Hi Manfred,
>
> Manfred Spraul wrote:
>
>> Additionally, you must replace the sleep_on calls with wait_event, or 
>> an open-coded wait queue: sleep_on is racy, it only works with cli().
>
>
>     Oh, I didn't no that..
>
>> IMHO the right way to fix cli() is
>> - add a single spinlock to the driver or the device structure. Do not 
>> forget the spin_lock_init().
>> - replace cli/sti with spin_lock_irqsave/spin_unlock_irqsave.
>
>
>     Yes.
>
>> - Additionally acquire the spinlock in every interrupt handler (cli() 
>> stops all interrupts, spinlocks only stop interrupt on the current cpu).
>> - check if there were recursive cli() calls. Fix them.
>> - replace all sleep_on calls with wait queue calls.
>> - check if there are any kmalloc or schedule calls in the area now 
>> under the spinlock, and reorganize the code.
>
>
>     But doesn't wait_queue call schedule()?

Yes, it does. You need a larger change to fix that. Something like the 
attached patch.

--
    Manfred