From 18ca2ce160ffff977f28456039f2475a3b500bc0 Mon Sep 17 00:00:00 2001 From: Jie Li Date: Mon, 11 May 2026 13:37:26 +0200 Subject: [PATCH] i2c: core: support recovery for single-ended GPIOs Currently, i2c_init_recovery() only assigns the set_sda/set_scl hooks if gpiod_get_direction() returns GPIO_LINE_DIRECTION_OUT. This logic fails on certain SoC controllers where open-drain lines in a high-impedance state are physically reported as inputs. This leads to a "deadlock" where the I2C core refuses to assign the recovery hooks because it incorrectly assumes the pins are input-only, even though they are fully capable of driving the bus low for recovery. Update the recovery initialization to use the new gpiod_is_single_ended() helper. If a GPIO is configured as open-drain or open-source in the firmware, it is safe to assume it can be used for bus recovery, even if the current hardware direction is reported as input. Signed-off-by: Jie Li Reviewed-by: Linus Walleij Acked-by: Wolfram Sang Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20260511113726.49041-3-jie.i.li@nokia.com --- drivers/i2c/i2c-core-base.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 3ec04787a737..fb25704219c7 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -446,7 +446,8 @@ static int i2c_init_recovery(struct i2c_adapter *adap) bri->set_scl = set_scl_gpio_value; if (bri->sda_gpiod) { bri->get_sda = get_sda_gpio_value; - if (gpiod_get_direction(bri->sda_gpiod) == GPIO_LINE_DIRECTION_OUT) + if (gpiod_get_direction(bri->sda_gpiod) == GPIO_LINE_DIRECTION_OUT || + gpiod_is_single_ended(bri->sda_gpiod)) bri->set_sda = set_sda_gpio_value; } } else if (bri->recover_bus == i2c_generic_scl_recovery) {