From 94d78e180c0323422854bc1718e657ac2d0cac1b Mon Sep 17 00:00:00 2001 From: Roel Kluin Date: Sat, 28 Mar 2009 21:34:42 +0100 Subject: 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 Signed-off-by: Jean Delvare Acked-by: Eric Brower --- drivers/i2c/algos/i2c-algo-pcf.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) (limited to 'drivers/i2c/algos') diff --git a/drivers/i2c/algos/i2c-algo-pcf.c b/drivers/i2c/algos/i2c-algo-pcf.c index 5906986d013b..65a769f3ae79 100644 --- a/drivers/i2c/algos/i2c-algo-pcf.c +++ b/drivers/i2c/algos/i2c-algo-pcf.c @@ -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; } /* -- cgit v1.2.3