[patch 82/96] i2c: Timeouts reach -1

Greg KH
2009-03-14T00:46:58Z

[-- Attachment #1: i2c-timeouts-reach-1.patch --]
[-- Type: text/plain, Size: 1717 bytes --]

2.6.27-stable review patch. If anyone has any objections, please let us know.

------------------

From: Roel Kluin <roel.kluin@gmail.com>

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>

---
drivers/i2c/busses/i2c-amd8111.c | 4 ++--
drivers/i2c/busses/i2c-pxa.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)

--- 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(st
{
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(str
{
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) {
--- 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 px

i2c_pxa_start_message(i2c);

- while (timeout-- && i2c->msg_num > 0) {
+ while (i2c->msg_num > 0 && --timeout) {
i2c_pxa_handler(0, i2c);
udelay(10);
}