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.