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Commit 94d78e18 authored by Roel Kluin's avatar Roel Kluin Committed by Jean Delvare
Browse files

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: default avatarRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
Acked-by: default avatarEric Brower <ebrower@gmail.com>
parent 0c168ceb

drivers/i2c/algos/i2c-algo-pcf.c

+10 −8
Original line number Diff line number Diff line
@@ -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);

	}
@@ -142,9 +144,9 @@ static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) 
		return -EINTR;

	}



	if (timeout <= 0)

		return -1;

	else

	if (timeout == 0)

		return -ETIMEDOUT;



	return 0;

}