On Mon, Aug 20, 2018 at 8:32 AM Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> wrote: > Trying to work out the right event if it's not sure that the examined > gpio actually moved is impossible. I applied the patch with the following reasoning. 1) Uwe has a usecase and hardware that needs this so he can do what he needs to do. I.e. the patch corresponds to a practical need of a user. 2) Only theoretical counter-arguments. 3) Uwe clarified that it is fine to put IRQ sharing back if/when we support level-triggered IRQs from userspace. This makes a lot of sense to me. 4) Rough consensus and running code. I edited the subject and commit message to reflect that we are talking about the userspace events here, not in-kernel users. Edge triggers are tricky and I feel a bit uncertain about how we handle all kinds of electronics out there. I can think about a few design mistakes. At one point I had the feeling level interrupts on GPIO lines are completely bogus, but I guess they make some sense for an intelligent peripheral (like on I2C) with it own internal status register that you then go and handle in a thread. Yours, Linus Walleij