On Fri, Jun 10, 2016 at 7:14 AM, Sergei Shtylyov
[off-list ref] wrote:

On 6/3/2016 3:14 PM, Rob Herring wrote:

quoted

quoted

of_irq_get() returns 0 iff irq_create_of_mapping() call fails. Returning
both error code  and 0 on failure is a sign of a misdesigned API. Return
-ENXIO instead like one of the callers, platform_get_irq(), does; fix up
the kernel-doc as well...

Signed-off-by: Sergei Shtylyov <redacted>

So I think this is done this way because of the variation in NO_IRQ
definition across architectures.

   I remember that NO_IRQ is "considered harmful" by Linus. Actually, I'm
nit sure what you mean, could you elaborate on that?

Calling locations could handle 0 vs. negative differently. The return
value propagates as well, so you can't easily audit how it is handled.
I'm being paranoid, but we need a better reason than "misdesigned
API". I'm pretty sure we misdesigned it on purpose.

Rob