Hi Marc.

2017-09-07 21:39 GMT+09:00 Marc Zyngier [off-list ref]:

quoted

I think there is a possibility where a device tries to get IRQ
after irq_domain_create_hierarchy(), but before irq_domain_push_irq().

      priv->domain = irq_domain_create_hierarchy(...)
      if (!priv->domain)
              return -ENOMEM;

        [  *** What if a irq consumer device request the irq here? *** ]

We've explicitly forbidden such a use case. There is a (not exactly fool
proof) check in irq_domain_push_irq(), but it is pretty easy to bypass
it. "Don't do it" is the conclusion we reached with David Daney.

If you don't want these interrupts to be requested, you might as well
flag them as IRQ_NOREQUEST, and unflag them when the hierarchy is ready.

Would that work for you?

Sorry if my description was unclear.

I do not think IRQ_NOREQUEST is equivalent
to IRQ_DOMAIN_FLAG_NO_CREATE I am trying to add in 5/6.


My intention is to prevent platform_get_irq()
from allocating a new virq.

I think IRQ_NOREQUEST only affects request_irq().



Having said that, this series got negative response
as a whole.

My motivation is to get my GPIO driver (6/6) in
by hook or by crook.
If you do not like this series, please feel free to throw it away.




-- 
Best Regards
Masahiro Yamada