[PATCH] fix PCA waitforcompletion() return value

Yegor Yefremov
2010-09-22T09:20:48Z

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-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
Reviewed-by: Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>

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;
}