>>> You should trace the exception path in the I-pipe patch to find the
>>>  point where your exception handling callback is not called.
>>
>> will it be a large print work or there are another ways to do that?
>> :)
>
> Yes, a small printk works. There is not that much code involved.

I have found the problem.
I used a printf some instructions before the call to the asm blob.
Once removed seems to work as expected.
I've seen also that writing
      printf(expr); \
      rt_task_set_mode(0, T_PRIMARY, 0);
it works (I think printf does a switch to secondary domain).
Now I should use a user-space-no-problem print like rtdm_printk in kernel space.
The docs says rtdm_in_rt_context and rtdm_printk are avalaible but in the rtdm.h
there is no trace of them and I can't use rtdm_driver.h 'cause it's kernel only...

    Gabriele