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@xxxxxxxxx>
---
Changes in v2:
- rebased on 110bc76729d4 of Linus's tree;
drivers/i2c/busses/i2c-davinci.c | 42 +++++++++++++++++--------------------
1 files changed, 19 insertions(+), 23 deletions(-)
diff --git a/drivers/i2c/busses/i2c-davinci.c b/drivers/i2c/busses/i2c-davinci.c
index df96ab6..03afdee 100644
--- a/drivers/i2c/busses/i2c-davinci.c
+++ b/drivers/i2c/busses/i2c-davinci.c
@@ -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;
- i2c_recover_bus(&dev->adapter);
- }
- }
- if (allow_sleep)
- schedule_timeout(1);
- }
+ 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);
+
+ /*
+ * 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;
}
@@ -508,7 +504,7 @@ 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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