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i2c-algo-pcf: Handle timeout correctly 

With a postfix decrement these timeouts reach -1 rather than 0, but after the
loop it is tested whether they have become 0.

As pointed out by Jean Delvare, the msg_num should be tested before the timeout.
With the current order, you could exit with a timeout error while all the
messages were successfully transferred.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Eric Brower <ebrower@gmail.com>
This commit is contained in:
Roel Kluin 2009-03-28 21:34:42 +01:00 committed by Jean Delvare
parent 0c168ceb9e
commit 94d78e180c
1 changed files with 10 additions and 8 deletions
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18
drivers/i2c/algos/i2c-algo-pcf.c
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@ -115,15 +115,17 @@ static int wait_for_bb(struct i2c_algo_pcf_data *adap)
status = get_pcf(adap, 1);
while (timeout-- && !(status & I2C_PCF_BB)) {
while (!(status & I2C_PCF_BB) && --timeout) {
udelay(100); /* wait for 100 us */
status = get_pcf(adap, 1);
}
if (timeout <= 0)
if (timeout == 0) {
printk(KERN_ERR "Timeout waiting for Bus Busy\n");
return -ETIMEDOUT;
}
return timeout <= 0;
return 0;
}
static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
@ -133,7 +135,7 @@ static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
*status = get_pcf(adap, 1);
while (timeout-- && (*status & I2C_PCF_PIN)) {
while ((*status & I2C_PCF_PIN) && --timeout) {
adap->waitforpin(adap->data);
*status = get_pcf(adap, 1);
}
@ -142,10 +144,10 @@ static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
return -EINTR;
}
if (timeout <= 0)
return -1;
else
return 0;
if (timeout == 0)
return -ETIMEDOUT;
return 0;
}
/*