This is a note to let you know that I've just added the patch titled gpio: pcf857x: Fix missing first interrupt to the 5.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: gpio-pcf857x-fix-missing-first-interrupt.patch and it can be found in the queue-5.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a8002a35935aaefcd6a42ad3289f62bab947f2ca Mon Sep 17 00:00:00 2001 From: Maxim Kiselev <bigunclemax@xxxxxxxxx> Date: Wed, 17 Feb 2021 14:10:00 +0100 Subject: gpio: pcf857x: Fix missing first interrupt From: Maxim Kiselev <bigunclemax@xxxxxxxxx> commit a8002a35935aaefcd6a42ad3289f62bab947f2ca upstream. If no n_latch value will be provided at driver probe then all pins will be used as an input: gpio->out = ~n_latch; In that case initial state for all pins is "one": gpio->status = gpio->out; So if pcf857x IRQ happens with change pin value from "zero" to "one" then we miss it, because of "one" from IRQ and "one" from initial state leaves corresponding pin unchanged: change = (gpio->status ^ status) & gpio->irq_enabled; The right solution will be to read actual state at driver probe. Cc: stable@xxxxxxxxxxxxxxx Fixes: 6e20a0a429bd ("gpio: pcf857x: enable gpio_to_irq() support") Signed-off-by: Maxim Kiselev <bigunclemax@xxxxxxxxx> Signed-off-by: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpio/gpio-pcf857x.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/gpio/gpio-pcf857x.c +++ b/drivers/gpio/gpio-pcf857x.c @@ -332,7 +332,7 @@ static int pcf857x_probe(struct i2c_clie * reset state. Otherwise it flags pins to be driven low. */ gpio->out = ~n_latch; - gpio->status = gpio->out; + gpio->status = gpio->read(gpio->client); status = devm_gpiochip_add_data(&client->dev, &gpio->chip, gpio); if (status < 0) Patches currently in stable-queue which might be from bigunclemax@xxxxxxxxx are queue-5.4/gpio-pcf857x-fix-missing-first-interrupt.patch