Re: [PATCH v3] gpio: interrupt consistency check for OF GPIO IRQs

Stephen Warren
2013-09-03T17:22:23Z

On 08/31/2013 09:32 AM, anish singh wrote:
> On Sat, Aug 31, 2013 at 1:23 AM, Stephen Warren <swarren@wwwdotorg.org
> <mailto:swarren@wwwdotorg.org>> wrote:

> I still haven't seen an answer to why we really care about this; how
> many times has code actually allocated the same GPIO/IRQ when it
> shouldn't, in a way that it wasn't detectable by some other mechanism,
> i.e. the feature just not working? Why are we even trying to solve this
> issue? I'm not totally convinced it even makes sense to try and
> solve it.
>
>
> Probably this issue(same gpio/irq being used by multiple drivers) is
> very rare
> but debugging it is bit difficult.

Really? It's easy to just look in /proc/interrupts and
/sys/kernel/debug/gpio.

> This generally happens when we are working
> on latest revised boards where latest gpio number of some driver
> conflicts with the some other driver.

At least in the DT case, which is all that this patch solves, the DT is
describing the HW GPIO/IRQ numbers, so the Linux GPIO numbers are
irrelevant; everything is expressed as raw HW numbers, which are quite
easy to check.