Re: [PATCH] pinctrl: armada-37xx: Add edge both type gpio irq support

From: Andrew Lunn
Date: Tue Oct 31 2017 - 09:16:25 EST


> Patch applied.
>
> The discussion here is interesting, it is customary for GPIO drivers
> to implement double-edge detection emulation by swapping the
> edge detector around like this.

Hi Linus

I was not aware this was customary.

> It might be possible to collect some generic information about
> this in the Documentation/gpio/driver.txt document.

Yes, i think it should be documented somewhere. Even in the use case
here, detecting an SD card being inserted/removed, you could get some
bounce on the microswitch, miss an edge, and be in the wrong state.

Andrew