[PATCH 1/1] gpio: twl4030: Fix regression for twl gpio LED output
From: tony@atomide.com (Tony Lindgren)
Date: 2013-12-04 17:37:13
Also in:
linux-gpio, linux-omap, lkml
* Roger Quadros [off-list ref] [131204 03:35]:
Commit 0b2aa8be introduced a regression that causes failure in setting LED GPO direction to OUT. This causes USB host probe failures for Beagleboard C4. [ 2.075469] platform usb_phy_gen_xceiv.2: Driver usb_phy_gen_xceiv requests probe deferral [ 2.090454] hsusb2_vcc: Failed to request enable GPIO510: -22 [ 2.100982] reg-fixed-voltage reg-fixed-voltage.0.auto: Failed to register regulator: -22 [ 2.109954] reg-fixed-voltage: probe of reg-fixed-voltage.0.auto failed with error -22 direction_out/direction_in must return 0 if the operation succeeded.
Uh, OK, sorry that was an unexpected side effect. We still should keep the return values though instead of just ignoring them.
quoted hunk ↗ jump to hunk
1 file changed, 9 insertions(+), 6 deletions(-)diff --git a/drivers/gpio/gpio-twl4030.c b/drivers/gpio/gpio-twl4030.c index b97d6a6..0999ed1 100644 --- a/drivers/gpio/gpio-twl4030.c +++ b/drivers/gpio/gpio-twl4030.c@@ -294,13 +294,13 @@ out: static int twl_direction_in(struct gpio_chip *chip, unsigned offset) { struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); - int ret; + int ret = 0; mutex_lock(&priv->mutex); if (offset < TWL4030_GPIO_MAX) - ret = twl4030_set_gpio_direction(offset, 1); + twl4030_set_gpio_direction(offset, 1); else - ret = -EINVAL; + ret = -EINVAL; /* LED outputs can't be set as input */ if (!ret) priv->direction &= ~BIT(offset);
This looks OK to me.
quoted hunk ↗ jump to hunk
@@ -354,18 +354,21 @@ static void twl_set(struct gpio_chip *chip, unsigned offset, int value) static int twl_direction_out(struct gpio_chip *chip, unsigned offset, int value) { struct gpio_twl4030_priv *priv = to_gpio_twl4030(chip); - int ret = -EINVAL;
Can't you just have: int ret = 0;
mutex_lock(&priv->mutex); if (offset < TWL4030_GPIO_MAX) - ret = twl4030_set_gpio_direction(offset, 0); + twl4030_set_gpio_direction(offset, 0); + + /* + * LED gpio's i.e. offset >= TWL4030_GPIO_MAX are always output + */ priv->direction |= BIT(offset); mutex_unlock(&priv->mutex); twl_set(chip, offset, value); - return ret; + return 0; }
Then the rest of this change is not needed and we check the return value for twl4030_set_gpio_direction. Makes sense to keep the comment there though. Regards, Tony