From: Roel Kluin <roel.kluin@gmail.com>
Date: Wed, 25 Feb 2009 20:26:21 +0000 (+0100)
Subject: i2c: Timeouts reach -1
X-Git-Tag: v2.6.27.20~15
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=faccffd54fa78cc094740ccc902e0a1189c61c27;p=thirdparty%2Fkernel%2Fstable.git

i2c: Timeouts reach -1

commit a746b578d8406b2db0e9f0d040061bc1f78433cf upstream

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 condition we are waiting for should
also be tested before the timeout. With the current order, you could
exit with a timeout error while the job is actually done.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/i2c/busses/i2c-amd8111.c b/drivers/i2c/busses/i2c-amd8111.c
index 3972208876b3d..c688237388028 100644
--- a/drivers/i2c/busses/i2c-amd8111.c
+++ b/drivers/i2c/busses/i2c-amd8111.c
@@ -72,7 +72,7 @@ static unsigned int amd_ec_wait_write(struct amd_smbus *smbus)
 {
 	int timeout = 500;
 
-	while (timeout-- && (inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_IBF))
+	while ((inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_IBF) && --timeout)
 		udelay(1);
 
 	if (!timeout) {
@@ -88,7 +88,7 @@ static unsigned int amd_ec_wait_read(struct amd_smbus *smbus)
 {
 	int timeout = 500;
 
-	while (timeout-- && (~inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_OBF))
+	while ((~inb(smbus->base + AMD_EC_SC) & AMD_EC_SC_OBF) && --timeout)
 		udelay(1);
 
 	if (!timeout) {
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index 44d838410f158..cdbae973a4bf3 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -604,7 +604,7 @@ static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
 
 	i2c_pxa_start_message(i2c);
 
-	while (timeout-- && i2c->msg_num > 0) {
+	while (i2c->msg_num > 0 && --timeout) {
 		i2c_pxa_handler(0, i2c);
 		udelay(10);
 	}