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authorRoel Kluin <roel.kluin@gmail.com>2009-03-28 16:34:42 -0400
committerJean Delvare <khali@linux-fr.org>2009-03-28 16:34:42 -0400
commit94d78e180c0323422854bc1718e657ac2d0cac1b (patch)
tree7db1c35614e593f80ee17c10915dda76d2ee2836 /drivers/i2c/algos
parent0c168ceb9e1898a7f2895e80ce9915835b083bd3 (diff)
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>
Diffstat (limited to 'drivers/i2c/algos')
-rw-r--r--drivers/i2c/algos/i2c-algo-pcf.c18
1 files changed, 10 insertions, 8 deletions
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)
115 115
116 status = get_pcf(adap, 1); 116 status = get_pcf(adap, 1);
117 117
118 while (timeout-- && !(status & I2C_PCF_BB)) { 118 while (!(status & I2C_PCF_BB) && --timeout) {
119 udelay(100); /* wait for 100 us */ 119 udelay(100); /* wait for 100 us */
120 status = get_pcf(adap, 1); 120 status = get_pcf(adap, 1);
121 } 121 }
122 122
123 if (timeout <= 0) 123 if (timeout == 0) {
124 printk(KERN_ERR "Timeout waiting for Bus Busy\n"); 124 printk(KERN_ERR "Timeout waiting for Bus Busy\n");
125 return -ETIMEDOUT;
126 }
125 127
126 return timeout <= 0; 128 return 0;
127} 129}
128 130
129static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status) 131static 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)
133 135
134 *status = get_pcf(adap, 1); 136 *status = get_pcf(adap, 1);
135 137
136 while (timeout-- && (*status & I2C_PCF_PIN)) { 138 while ((*status & I2C_PCF_PIN) && --timeout) {
137 adap->waitforpin(adap->data); 139 adap->waitforpin(adap->data);
138 *status = get_pcf(adap, 1); 140 *status = get_pcf(adap, 1);
139 } 141 }
@@ -142,10 +144,10 @@ static int wait_for_pin(struct i2c_algo_pcf_data *adap, int *status)
142 return -EINTR; 144 return -EINTR;
143 } 145 }
144 146
145 if (timeout <= 0) 147 if (timeout == 0)
146 return -1; 148 return -ETIMEDOUT;
147 else 149
148 return 0; 150 return 0;
149} 151}
150 152
151/* 153/*