[34-longterm 185/260] i2c-pca: Fix waitforcompletion() return value

Paul Gortmaker
2011-01-02T07:41:34Z

From: Yegor Yefremov <yegor_sub1@visionsystems.de>

commit 6abb930af064fb1cf4177d32e2c7bfb89eee0fe5 upstream.

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>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/i2c/busses/i2c-pca-isa.c | 12 ++++++++----
drivers/i2c/busses/i2c-pca-platform.c | 11 +++++++----
2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-pca-isa.c b/drivers/i2c/busses/i2c-pca-isa.c
index f7346a9..62a5ce5 100644
--- a/drivers/i2c/busses/i2c-pca-isa.c
+++ b/drivers/i2c/busses/i2c-pca-isa.c
@@ -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;
}

diff --git a/drivers/i2c/busses/i2c-pca-platform.c b/drivers/i2c/busses/i2c-pca-platform.c
index 5b2213d..1d8c208 100644
--- a/drivers/i2c/busses/i2c-pca-platform.c
+++ b/drivers/i2c/busses/i2c-pca-platform.c
@@ -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;
--
1.7.3.3