David Bauer 6d59f4eeb4 gpio-button-hotplug: unify polled and interrupt code ... This patch unifies the polled and interrupt-driven gpio_keys code paths as well implements consistent handling of the debounce interval set for the GPIO buttons and switches. Hotplug events will only be fired if 1. The input changes its state and remains stable for the duration of the debounce interval (default is 5 ms). 2. In the initial stable (no state-change for duration of the debounce interval) state once the driver module gets loaded. Switch type inputs will always report their stable state. Unpressed buttons will not trigger an event for the initial stable state. Whereas pressed buttons will trigger an event. This is consistent with upstream's gpio-key driver that uses the input subsystem (and dont use autorepeat). Prior to this patch, this was handled inconsistently for interrupt-based an polled gpio-keys. Hence this patch unifies the shared logic into the gpio_keys_handle_button() function and modify both implementations to handle the initial state properly. The changes described in 2. ) . can have an impact on the failsafe trigger. Up until now, the script checked for button state changes. On the down side, this allowed to trigger the failsafe by releasing a held button at the right time. On the plus side, the button's polarity setting didn't matter. Now, the failsafe will only engage when a button was pressed at the right moment (same as before), but now it can theoretically also trigger when the button was pressed the whole time the kernel booted and well into the fast-blinking preinit phase. However, the chances that this can happen are really small. This is because the gpio-button module is usually up and ready even before the preinit state is entered. So, the initial pressed button event gets lost and most devices behave as before. Bisectors: If this patch causes a device to permanently go into failsafe or experience weird behavior due to inputs, please check the following: - the GPIO polarity setting for the button - the software-debounce value Run-tested for 'gpio-keys' and 'gpio-keys-polled' on - devolo WiFi pro 1200e - devolo WiFi pro 1750c - devolo WiFi pro 1750x - Netgear WNDR4700 - Meraki MR24 - RT-AC58U Signed-off-by: David Bauer <mail@david-bauer.net> Signed-off-by: Christian Lamparter <chunkeey@gmail.com> [further cleanups, simplification and unification] (cherry picked from commit 27f3f493de)		2019-07-19 17:04:30 +02:00
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src	gpio-button-hotplug: unify polled and interrupt code	2019-07-19 17:04:30 +02:00
Makefile	build: use KERNEL_MAKE_FLAGS for kernel file compilations	2017-10-29 16:17:05 +01:00