[PATCH v2] gpio: Add Avionic Design N-bit GPIO expander support

[Linus Walleij]

On Thu, Aug 9, 2012 at 10:20 PM, Thierry Reding
<thierry.reding at avionic-design.de> wrote:
> On Sun, Jul 29, 2012 at 07:13:57PM +0200, Linus Walleij wrote:
>> > +       client->irq = irq_of_parse_and_map(client->dev.of_node, 0);
>> > +       if (client->irq == NO_IRQ)
>>
>> Just if (!client->irq) since NO_IRQ is 0 nowadays.
>
> At the risk of seeming pedantic, NO_IRQ is in fact quite often not 0.

No. A year back, yes, but not anymore. We went to great lengths in the
ARM architecture to ensure NO_IRQ is *always 0. Russell spent
a lot of time on this.

Consult the following article on LWN:
http://lwn.net/Articles/470820/

Then grep your gitlog and you'll see we got rid of it from ARM.

If this driver is for some other arch like openrisc I might accept
it but please reconsider.

Yours,
Linus Walleij