The default configuration of a pin is often with a value in the pull-up/down field at chip reset. So, even if the internal logic of the controller prevents writing a configuration with pull-up and pull-down at the same time, we must ensure explicitly this condition before writing the register. This was leading to a pull-down condition not taken into account for instance. Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx> Fixes: 776180848b57 ("pinctrl: introduce driver for Atmel PIO4 controller") Cc: stable@xxxxxxxxxxxxxxx #v4.4 and later --- drivers/pinctrl/pinctrl-at91-pio4.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/pinctrl/pinctrl-at91-pio4.c b/drivers/pinctrl/pinctrl-at91-pio4.c index 629b6fe..75093d7 100644 --- a/drivers/pinctrl/pinctrl-at91-pio4.c +++ b/drivers/pinctrl/pinctrl-at91-pio4.c @@ -722,9 +722,11 @@ static int atmel_conf_pin_config_group_set(struct pinctrl_dev *pctldev, break; case PIN_CONFIG_BIAS_PULL_UP: conf |= ATMEL_PIO_PUEN_MASK; + conf &= (~ATMEL_PIO_PDEN_MASK); break; case PIN_CONFIG_BIAS_PULL_DOWN: conf |= ATMEL_PIO_PDEN_MASK; + conf &= (~ATMEL_PIO_PUEN_MASK); break; case PIN_CONFIG_DRIVE_OPEN_DRAIN: if (arg == 0) -- 2.5.0 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html