Remove these locks - they aren't strictly needed and cause measurable

performance issues.

* Access to the GPIO bus is already locked by requesting
  and releasing the bus - thus the lock isn't really needed
  for each GPIO pin change.
* Don't lock and unlock the GPIO bus for -each- i2c access -
  the i2c bus code is already doing this by calling the upper
  layer callback to request/release the bus. This thus locks
  the bus for the entirety of the transaction.

TODO:

* Further verify that everything is correctly requesting/
  releasing the GPIO bus.
* Look at how to lock the GPIO pin configuration stuff,
  potentially by locking/unlocking the bus at the gpiobus
  layer.

2 files changed, 0 insertions, 24 deletions

diff --git a/sys/dev/gpio/gpioiic.c b/sys/dev/gpio/gpioiic.c
index b5876b5..923b21f 100644
--- a/sys/dev/gpio/gpioiic.c
+++ b/sys/dev/gpio/gpioiic.c
@@ -55,7 +55,6 @@ struct gpioiic_softc
 {
 	device_t	sc_dev;
 	device_t	sc_busdev;
-	struct mtx	sc_mtx;
 	struct cdev	*sc_leddev;
 	int		scl_pin;
 	int		sda_pin;
@@ -148,7 +147,6 @@ gpioiic_setsda(device_t dev, int val)
 {
 	struct gpioiic_softc		*sc = device_get_softc(dev);
 
-	GPIOBUS_LOCK_BUS(sc->sc_busdev);
 	if (val == 0) {
 		GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 0);
 		GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin,
@@ -157,7 +155,6 @@ gpioiic_setsda(device_t dev, int val)
 		GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin,
 		    GPIO_PIN_INPUT);
 	}
-	GPIOBUS_UNLOCK_BUS(sc->sc_busdev);
 }
 
 static void
@@ -165,7 +162,6 @@ gpioiic_setscl(device_t dev, int val)
 {
 	struct gpioiic_softc		*sc = device_get_softc(dev);
 
-	GPIOBUS_LOCK_BUS(sc->sc_busdev);
 	if (val == 0) {
 		GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 0);
 		GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin,
@@ -174,7 +170,6 @@ gpioiic_setscl(device_t dev, int val)
 		GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin,
 		    GPIO_PIN_INPUT);
 	}
-	GPIOBUS_UNLOCK_BUS(sc->sc_busdev);
 }
 
 static int
@@ -183,11 +178,9 @@ gpioiic_getscl(device_t dev)
 	struct gpioiic_softc		*sc = device_get_softc(dev);
 	unsigned int			val;
 
-	GPIOBUS_LOCK_BUS(sc->sc_busdev);
 	GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin,
 	    GPIO_PIN_INPUT);
 	GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, &val);
-	GPIOBUS_UNLOCK_BUS(sc->sc_busdev);
 
 	return ((int)val);
 }
@@ -198,11 +191,9 @@ gpioiic_getsda(device_t dev)
 	struct gpioiic_softc		*sc = device_get_softc(dev);
 	unsigned int			val;
 
-	GPIOBUS_LOCK_BUS(sc->sc_busdev);
 	GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin,
 	    GPIO_PIN_INPUT);
 	GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, &val);
-	GPIOBUS_UNLOCK_BUS(sc->sc_busdev);
 
 	return ((int)val);
 }
@@ -212,13 +203,11 @@ gpioiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
 {
 	struct gpioiic_softc		*sc = device_get_softc(dev);
 
-	GPIOBUS_LOCK_BUS(sc->sc_busdev);
 	GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev);
 
 	gpioiic_reset_bus(sc->sc_dev);
 
 	GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev);
-	GPIOBUS_UNLOCK_BUS(sc->sc_busdev);
 
 	return (IIC_ENOADDR);
 }
diff --git a/sys/mips/atheros/ar71xx_gpio.c b/sys/mips/atheros/ar71xx_gpio.c
index 11906ff..592cd2b 100644
--- a/sys/mips/atheros/ar71xx_gpio.c
+++ b/sys/mips/atheros/ar71xx_gpio.c
@@ -89,17 +89,13 @@ static int ar71xx_gpio_pin_toggle(device_t dev, uint32_t pin);
 static void
 ar71xx_gpio_function_enable(struct ar71xx_gpio_softc *sc, uint32_t mask)
 {
-	GPIO_LOCK(sc);
 	GPIO_SET_BITS(sc, AR71XX_GPIO_FUNCTION, mask);
-	GPIO_UNLOCK(sc);
 }
 
 static void
 ar71xx_gpio_function_disable(struct ar71xx_gpio_softc *sc, uint32_t mask)
 {
-	GPIO_LOCK(sc);
 	GPIO_CLEAR_BITS(sc, AR71XX_GPIO_FUNCTION, mask);
-	GPIO_UNLOCK(sc);
 }
 
 static void
@@ -109,7 +105,6 @@ ar71xx_gpio_pin_configure(struct ar71xx_gpio_softc *sc, struct gpio_pin *pin,
 	uint32_t mask;
 
 	mask = 1 << pin->gp_pin;
-	GPIO_LOCK(sc);
 
 	/*
 	 * Manage input/output
@@ -125,8 +120,6 @@ ar71xx_gpio_pin_configure(struct ar71xx_gpio_softc *sc, struct gpio_pin *pin,
 			GPIO_CLEAR_BITS(sc, AR71XX_GPIO_OE, mask);
 		}
 	}
-
-	GPIO_UNLOCK(sc);
 }
 
 static int
@@ -253,12 +246,10 @@ ar71xx_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
 	if (i >= sc->gpio_npins)
 		return (EINVAL);
 
-	GPIO_LOCK(sc);
 	if (value)
 		GPIO_WRITE(sc, AR71XX_GPIO_SET, (1 << pin));
 	else
 		GPIO_WRITE(sc, AR71XX_GPIO_CLEAR, (1 << pin));
-	GPIO_UNLOCK(sc);
 
 	return (0);
 }
@@ -277,9 +268,7 @@ ar71xx_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *val)
 	if (i >= sc->gpio_npins)
 		return (EINVAL);
 
-	GPIO_LOCK(sc);
 	*val = (GPIO_READ(sc, AR71XX_GPIO_IN) & (1 << pin)) ? 1 : 0;
-	GPIO_UNLOCK(sc);
 
 	return (0);
 }
@@ -298,13 +287,11 @@ ar71xx_gpio_pin_toggle(device_t dev, uint32_t pin)
 	if (i >= sc->gpio_npins)
 		return (EINVAL);
 
-	GPIO_LOCK(sc);
 	res = (GPIO_READ(sc, AR71XX_GPIO_IN) & (1 << pin)) ? 1 : 0;
 	if (res)
 		GPIO_WRITE(sc, AR71XX_GPIO_CLEAR, (1 << pin));
 	else
 		GPIO_WRITE(sc, AR71XX_GPIO_SET, (1 << pin));
-	GPIO_UNLOCK(sc);
 
 	return (0);
 }