Re: [PATCH] drm: adv7511: really enable interrupts for EDID detection

[Wolfram Sang <wsa@the-dreams.de>]

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On Thu, Nov 26, 2015 at 01:43:33PM +0100, Lars-Peter Clausen wrote:
> On 11/25/2015 09:27 AM, Wolfram Sang wrote:
> > 
> >> I guess you mean that the GPIO callbacks include Runtime PM handling
> >> however for irq_chip Runtime PM may not be hooked up so the GPIO block
> >> is in such case is not powered on / get clock enabled?
> > 
> > Yes. There is another drawback when GPIOs are not properly requested. It
> > is still possible to request them from userspace although a kernel
> > driver is using them. I am playing with the idea that the GPIO core
> > auto-requests GPIOs which are not already requested but still set up as
> > interrupts.
> 
> I think the GPIO core already reserves the pins that are requested as IRQs.
> See gpiochip_lock_as_irq().

I could still export them via sysfs. They were also not showing up in
/sys/kernel/debug/gpio.

> As for PM see this discussion
> http://lkml.iu.edu/hypermail/linux/kernel/1511.1/01645.html

Nice! Thanks for this pointer.


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