Philippe Gerum wrote:
> Jan Kiszka wrote:
> 
> <snip>
> 
> Don't you mean this instead?
> 
>> -int ipipe_catch_event(struct ipipe_domain *ipd,
>> -              unsigned event,
>> -              int (*handler)(unsigned event, struct ipipe_domain
>> *ipd, void *data))
>> +ipipe_event_handler_t ipipe_catch_event(struct ipipe_domain *ipd,
>> +                    unsigned event,
>> +                    ipipe_event_handler_t handler)
>>  {
> +       ipipe_event_handler_t old_handler;
>>      int self = 0;
>>  
>> @@ -278,7 +278,7 @@
>>      }
>>  
>>      if (event >= IPIPE_NR_EVENTS)
>> -        return -EINVAL;
>> +        return NULL;
>>  
> -      if (!xchg(&ipd->evhand[event],handler))    {
> +      if (!(old_handler = xchg(&ipd->evhand[event],handler)))    {
>>          if (handler) {
>> @@ -301,7 +301,7 @@
>>              ipd->evself |= (1LL << event);
>>      }
>>  
>> -    return 0;
>> +    return handler;
> -    return handler;
> +    return old_handler;
>>  }
>>  
>>  cpumask_t ipipe_set_irq_affinity (unsigned irq, cpumask_t cpumask)
>>
>>

Ouch, obviously. A quick hack which was only tested for not breaking
existing software.

Jan