i2c-pca: Fix waitforcompletion() return value
Yegor Yefremov [Thu, 30 Sep 2010 12:14:22 +0000 (14:14 +0200)]
ret is still -1, if during the polling read_byte() returns at once
with I2C_PCA_CON_SI set. So ret > 0 would lead *_waitforcompletion()
to return 0, in spite of the proper behavior.

The routine was rewritten, so that ret has always a proper value,
before returning.

Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Cc: stable@kernel.org
Signed-off-by: Jean Delvare <khali@linux-fr.org>

drivers/i2c/busses/i2c-pca-isa.c
drivers/i2c/busses/i2c-pca-platform.c

index bbd7760..29933f8 100644 (file)
@@ -71,8 +71,8 @@ static int pca_isa_readbyte(void *pd, int reg)
 
 static int pca_isa_waitforcompletion(void *pd)
 {
-       long ret = ~0;
        unsigned long timeout;
+       long ret;
 
        if (irq > -1) {
                ret = wait_event_timeout(pca_wait,
@@ -81,11 +81,15 @@ static int pca_isa_waitforcompletion(void *pd)
        } else {
                /* Do polling */
                timeout = jiffies + pca_isa_ops.timeout;
-               while (((pca_isa_readbyte(pd, I2C_PCA_CON)
-                               & I2C_PCA_CON_SI) == 0)
-                               && (ret = time_before(jiffies, timeout)))
+               do {
+                       ret = time_before(jiffies, timeout);
+                       if (pca_isa_readbyte(pd, I2C_PCA_CON)
+                                       & I2C_PCA_CON_SI)
+                               break;
                        udelay(100);
+               } while (ret);
        }
+
        return ret > 0;
 }
 
index ef5c784..5f6d7f8 100644 (file)
@@ -80,8 +80,8 @@ static void i2c_pca_pf_writebyte32(void *pd, int reg, int val)
 static int i2c_pca_pf_waitforcompletion(void *pd)
 {
        struct i2c_pca_pf_data *i2c = pd;
-       long ret = ~0;
        unsigned long timeout;
+       long ret;
 
        if (i2c->irq) {
                ret = wait_event_timeout(i2c->wait,
@@ -90,10 +90,13 @@ static int i2c_pca_pf_waitforcompletion(void *pd)
        } else {
                /* Do polling */
                timeout = jiffies + i2c->adap.timeout;
-               while (((i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
-                               & I2C_PCA_CON_SI) == 0)
-                               && (ret = time_before(jiffies, timeout)))
+               do {
+                       ret = time_before(jiffies, timeout);
+                       if (i2c->algo_data.read_byte(i2c, I2C_PCA_CON)
+                                       & I2C_PCA_CON_SI)
+                               break;
                        udelay(100);
+               } while (ret);
        }
 
        return ret > 0;