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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: Alexander Sverdlin <alexander.sverdlin@nokia.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Alexander Sverdlin 2015-06-09 12:58:29 +02:00 committed by Wolfram Sang
parent dd1aa2524b
commit 72a956c556
1 changed files with 18 additions and 22 deletions
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40
drivers/i2c/busses/i2c-davinci.c
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@ -350,29 +350,25 @@ static struct i2c_bus_recovery_info davinci_i2c_scl_recovery_info = {
/* /*
* Waiting for bus not busy * Waiting for bus not busy
*/ */
static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev, static int i2c_davinci_wait_bus_not_busy(struct davinci_i2c_dev *dev)
char allow_sleep)
{ {
unsigned long timeout; unsigned long timeout = jiffies + dev->adapter.timeout;
static u16 to_cnt;
timeout = jiffies + dev->adapter.timeout; do {
while (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) if (!(davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB))
& DAVINCI_I2C_STR_BB) { return 0;
if (to_cnt <= DAVINCI_I2C_MAX_TRIES) { schedule_timeout_uninterruptible(1);
if (time_after(jiffies, timeout)) { } while (time_before_eq(jiffies, timeout));
dev_warn(dev->dev,
"timeout waiting for bus ready\n"); dev_warn(dev->dev, "timeout waiting for bus ready\n");
to_cnt++; i2c_recover_bus(&dev->adapter);
return -ETIMEDOUT;
} else { /*
to_cnt = 0; * if bus is still "busy" here, it's most probably a HW problem like
i2c_recover_bus(&dev->adapter); * short-circuit
} */
} if (davinci_i2c_read_reg(dev, DAVINCI_I2C_STR_REG) & DAVINCI_I2C_STR_BB)
if (allow_sleep) return -EIO;
schedule_timeout(1);
}
return 0; 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); 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) { if (ret < 0) {
dev_warn(dev->dev, "timeout waiting for bus ready\n"); dev_warn(dev->dev, "timeout waiting for bus ready\n");
return ret; return ret;