Hi Abhishek, On Thu, Oct 26, 2023 at 11:23:20AM +0530, Abhishek Kumar Singh wrote: > Dear Mr. Dmitry, > Greetings! > > > The patch removes unused many APIs call chain for every suspend/resume of the device > if no key press event triggered. > > > There is a call back function gpio_keys_resume() called for > every suspend/resume of the device. and whenever this function called, it is > reading the status of the key. And gpio_keys_resume() API further calls the > below chain of API irrespective of key press event > > > APIs call chain: > static void gpio_keys_report_state(struct gpio_keys_drvdata *ddata) > static void gpio_keys_gpio_report_event(struct gpio_button_data *bdata) > gpiod_get_value_cansleep(bdata->gpiod); > input_event(input, type, *bdata->code, state); > input_sync(input); > > > The patch avoid the above APIs call chain if there is no key press event triggered. > It will save the device computational resources, power resources and optimize the suspend/resume time Unfortunately it also breaks the driver as button->value does not hold the current state of the GPIO but rather set one via device tree so that the driver can use that value when sending EV_ABS events. So with typical GPIO-backed keys or buttons you change results in no events reported on resume. I also wonder what kind of measurements you did on improvements to suspend/resume time with your change. Thanks. -- Dmitry
