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@xxxxxxxxxxxxxx> Reviewed-by: Wolfram Sang <w.sang@xxxxxxxxxxxxxx> Index: b/drivers/i2c/busses/i2c-pca-platform.c =================================================================== --- a/drivers/i2c/busses/i2c-pca-platform.c 2010-09-22 09:31:12.000000000 +0200 +++ b/drivers/i2c/busses/i2c-pca-platform.c 2010-09-22 11:10:58.000000000 +0200 @@ -80,8 +80,8 @@ 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 @@ } 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; Index: b/drivers/i2c/busses/i2c-pca-isa.c =================================================================== --- a/drivers/i2c/busses/i2c-pca-isa.c 2010-08-27 01:47:12.000000000 +0200 +++ b/drivers/i2c/busses/i2c-pca-isa.c 2010-09-22 11:10:38.000000000 +0200 @@ -71,8 +71,8 @@ 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 @@ } 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; } -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html