Re: gpio irqchip initialization race

[Alexander Stein <alexander.stein@xxxxxxxxxxxxxxxxxxxxx>]

On Friday 01 April 2016 13:29:14, Linus Walleij wrote:
> On Fri, Apr 1, 2016 at 10:56 AM, Alexander Stein
> 
> <alexander.stein@xxxxxxxxxxxxxxxxxxxxx> wrote:
> > [Me]
> > 
> >> And in this case (if gpio_keys handle -EPROBE_DEFER gracefully)
> >> all should be fine with my oneliner patch.
> >> 
> >> I am more uncertain about the -EINVAL (-22) we might need some
> >> more analysis there.
> > 
> > I did 10 runs and got the following results:
> >> 3x  gpio-keys user_sw: Unable to claim irq 0; error -22
> >> 2x  gpio-keys user_sw: Unable to get irq number for GPIO 376, error -517
> >> 5x  ok
> > 
> > So, for one gpio-keys seems not to handle -EPROBE_DEFER gracefully
> 
> After reading the code the only problem seems to be that it prints that
> error. A small patch to silence that print should fix it then, can you
> confirm that in these cases the gpio-keys are retried later?

Ah, yes. You're right. I just checked for the error messages, but not if the 
device are actually absent. I just had a start where a (different) gpio-keys 
device failed with error -517 but is available when loggin in. So it really is 
just fix to silence on -DEFER_PROBE.

Best regards,
Alexander

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