Re: [patch 2.6.25-rc5 1/2] gpiolib: dynamic gpio number allocation

[Andrew Morton]

On Thu, 13 Mar 2008 15:18:58 -0800
David Brownell <david-b@xxxxxxxxxxx> wrote:

> On Thursday 13 March 2008, Andrew Morton wrote:
> 
> > hm.  I suppose that if someone want a huge number of GPIOs then we can
> > convert this to a bitmap or an IDR tree easily enough.
> 
> Actually, I tried IDRs for a while and they broke platforms
> which needed to initialize and use GPIOs early: before kmalloc
> would work.  A real PITA that was -- and slow too.

If IDRs were slow, that linear search will be glacial.

> 
> > Shouldn't ARCH_NR_GPIOS be CONFIG_NR_GPIOS?
> 
> No more than NR_IRQS is settable via Kconfig.  And for
> rather similar reasons.  :)

What are those reasons?
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