Re: [PATCH 2/2] powerpc/powernv/opal-dump : Use IRQ_HANDLED instead of numbers in interrupt handler

[Mukesh Ojha <mukesh02@linux.vnet.ibm.com>]

Hi Jeremy,


On Wednesday 15 February 2017 08:48 AM, Jeremy Kerr wrote:
> Hi Mukesh,
>
>> Converts all the return explicit number to a more proper IRQ_HANDLED,
>> which looks proper incase of interrupt handler returning case.
> This looks good to me, but can you describe the effects of those changes
> to the interrupt handler's return code? ie, what happened in the
> erroneous case where we returned 0 (== IRQ_NONE) - does this fix a
> user-visible issue?
>
> Cheers,

The return value of an interrupt handler is the special type 
irqreturn_t. An interrupt handler can return two special values,
IRQ_NONE or IRQ_HANDLED. The former is returned when the interrupt 
handler detects an interrupt for which its device was not
the originator. The latter is returned if the interrupt handler was 
correctly invoked, and its device did indeed cause the interrupt.

No, this is not user visible issue..and also here it does not matter 
what we return from here as we
are not handling the return value of the handler. This handler gets 
triggered when we get interrupt
from opal and in handler we do a opal call which on successful scenario 
disable the interrupt bit which
was set.

-Mukesh

>
>
> Jeremy
>