netdev - [PATCH] gianfar: Fix error in mdio reset timeout

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Date:	Mon, 22 Sep 2008 10:03:56 -0700
From:	Trent Piepho <tpiepho@...escale.com>
To:	netdev@...r.kernel.org
Cc:	Trent Piepho <tpiepho@...escale.com>
Subject: [PATCH] gianfar: Fix error in mdio reset timeout

The loop with the timeout used "while (...  && timeout--)", which means
than when the timeout occurs, "timeout" will be -1 after the loop has
exited.  The code that checks if the looped exited because of a timeout
used "if (timeout <= 0)".  Seems ok, except timeout is unsigned, and
(unsigned)-1 isn't less than zero!

Using "--timeout" in the loop fixes this problem, as now "timeout" will be
0 when the loop times out.

This also fixes a bug in the existing code, where it will erroneously think
a timeout occurred if the condition the loop was waiting for is satisfied
on the final iteration before a timeout.

Signed-off-by: Trent Piepho <tpiepho@...escale.com>
Acked-by: Andy Fleming <afleming@...escale.com>
---
 drivers/net/gianfar_mii.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/gianfar_mii.c b/drivers/net/gianfar_mii.c
index ebcfb27..906aba2 100644
--- a/drivers/net/gianfar_mii.c
+++ b/drivers/net/gianfar_mii.c
@@ -136,12 +136,12 @@ static int gfar_mdio_reset(struct mii_bus *bus)

 	/* Wait until the bus is free */
 	while ((gfar_read(&regs->miimind) & MIIMIND_BUSY) &&
-			timeout--)
+			--timeout)
 		cpu_relax();

 	mutex_unlock(&bus->mdio_lock);

-	if(timeout <= 0) {
+	if(timeout == 0) {
 		printk(KERN_ERR "%s: The MII Bus is stuck!\n",
 				bus->name);
 		return -EBUSY;
-- 
1.5.4.1

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