Re: [PATCH] i2c: test off by one in {piix4,vt596}_transaction()

From: Roel Kluin
Date: Tue Jan 05 2010 - 16:18:51 EST


With `while (timeout++ < MAX_TIMEOUT)' timeout reaches MAX_TIMEOUT + 1 after the loop
This is probably unlikely to produce a problem.

Signed-off-by: Roel Kluin <roel.kluin@xxxxxxxxx>
---
> That's right... but I'd rather change the loops to use "++timeout" and
> leave the conditions as is (or maybe change it to "=="). I think it's
> easier to read that way. Would that be OK with you?

Ok,

drivers/i2c/busses/i2c-piix4.c | 4 ++--
drivers/i2c/busses/i2c-viapro.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/i2c/busses/i2c-piix4.c b/drivers/i2c/busses/i2c-piix4.c
index 1e245e9..e56e4b6 100644
--- a/drivers/i2c/busses/i2c-piix4.c
+++ b/drivers/i2c/busses/i2c-piix4.c
@@ -324,12 +324,12 @@ static int piix4_transaction(void)
else
msleep(1);

- while ((timeout++ < MAX_TIMEOUT) &&
+ while ((++timeout < MAX_TIMEOUT) &&
((temp = inb_p(SMBHSTSTS)) & 0x01))
msleep(1);

/* If the SMBus is still busy, we give up */
- if (timeout >= MAX_TIMEOUT) {
+ if (timeout == MAX_TIMEOUT) {
dev_err(&piix4_adapter.dev, "SMBus Timeout!\n");
result = -ETIMEDOUT;
}
diff --git a/drivers/i2c/busses/i2c-viapro.c b/drivers/i2c/busses/i2c-viapro.c
index e4b1543..a84a909 100644
--- a/drivers/i2c/busses/i2c-viapro.c
+++ b/drivers/i2c/busses/i2c-viapro.c
@@ -165,10 +165,10 @@ static int vt596_transaction(u8 size)
do {
msleep(1);
temp = inb_p(SMBHSTSTS);
- } while ((temp & 0x01) && (timeout++ < MAX_TIMEOUT));
+ } while ((temp & 0x01) && (++timeout < MAX_TIMEOUT));

/* If the SMBus is still busy, we give up */
- if (timeout >= MAX_TIMEOUT) {
+ if (timeout == MAX_TIMEOUT) {
result = -ETIMEDOUT;
dev_err(&vt596_adapter.dev, "SMBus timeout!\n");
}
--
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