Commit 72a956c5 authored by Alexander Sverdlin's avatar Alexander Sverdlin Committed by Wolfram Sang
Browse files

i2c: davinci: Refactor i2c_davinci_wait_bus_not_busy() 



There are several problems in the function:
- "to_cnt" variable does nothing
- schedule_timeout() call without setting current state does nothing
- "allow_sleep" parameter is not really used

Refactor the function so that it really tries to wait. In case of timeout try
to recover the bus.

Signed-off-by: default avatarAlexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: default avatarWolfram Sang <wsa@the-dreams.de>
parent dd1aa252

drivers/i2c/busses/i2c-davinci.c

+19 −23
Original line number Diff line number Diff line
@@ -350,29 +350,25 @@ static struct i2c_bus_recovery_info davinci_i2c_scl_recovery_info = { 
/*

 * Waiting for bus not busy

 */

static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev,

					 char allow_sleep)

static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev)

{

	unsigned long timeout;

	static u16 to_cnt;



	timeout = jiffies + dev->adapter.timeout;

	while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG)

	       & DAVINCI_I2C_STR_BB) {

		if (to_cnt <= DAVINCI_I2C_MAX_TRIES) {

			if (time_after(jiffies, timeout)) {

				dev_warn(dev->dev,

				"timeout waiting for bus ready\n");

				to_cnt++;

				return -ETIMEDOUT;

			} else {

				to_cnt = 0;

	unsigned long timeout = jiffies + dev->adapter.timeout;



	do {

		if (!(davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB))

			return 0;

		schedule_timeout_uninterruptible(1);

	} while (time_before_eq(jiffies, timeout));



	dev_warn(dev->dev, "timeout waiting for bus ready\n");

	i2c_recover_bus(&dev->adapter);

			}

		}

		if (allow_sleep)

			schedule_timeout(1);

	}



	/*

	 * if bus is still "busy" here, it's most probably a HW problem like

	 * short-circuit

	 */

	if (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB)

		return -EIO;



	return 0;

}
@@ -505,7 +501,7 @@ i2c_davinci_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 


	dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num);



	ret = i2c_davinci_wait_bus_not_busy(dev, 1);

	ret = i2c_davinci_wait_bus_not_busy(dev);

	if (ret < 0) {

		dev_warn(dev->dev, "timeout waiting for bus ready\n");

		return ret;

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