sungem: limit reaches -1, but 0 tested

With a postfix decrement these reach -1 rather than 0, but after the loop it is tested to have become 0.

---

index 61843fd..78f8cee 100644
@@ -79,7 +79,7 @@ static int reset_one_mii_phy(struct mii_phy* phy, int phy_id)
 
 	udelay(100);
 
-	while (limit--) {
+	while (--limit) {
 		val = __phy_read(phy, phy_id, MII_BMCR);
 		if ((val & BMCR_RESET) == 0)
 			break;

From: Roel Kluin <[email protected]>
Date: Sat, 31 Jan 2009 13:42:36 +0100

Just like the case just pointed out in your 'net' version of this patch, it is being tested "<= 0" so this fix is not necessary at all.

Please carefully review all of your changes of this kind to make sure the test is strictly equality to zero rather than <= 0.

I'm dropping all of these postfix decrement patches.

The change is correct although the changelog is not clear. This is also true for the cassini patch, here included as well.

How about:

------------------>8----------------8<------------------------- while (limit--)

	if (test())
		break;

if (limit <= 0)

	goto test_failed;

In the last iteration, limit is decremented after the test to 0. If just thereafter test() succeeds and a break occurs, the goto still occurs because limit is 0.

---
 drivers/net/cassini.c    |    4 ++--
 drivers/net/sungem_phy.c |    2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

index 840b3d1..bbbc3bb 100644
@@ -806,7 +806,7 @@ static int cas_reset_mii_phy(struct cas *cp)
 
 	cas_phy_write(cp, MII_BMCR, BMCR_RESET);
 	udelay(100);
-	while (limit--) {
+	while (--limit) {
 		val = cas_phy_read(cp, MII_BMCR);
 		if ((val & BMCR_RESET) == 0)
 			break;

@@ -979,7 +979,7 @@ static void cas_phy_init(struct cas *cp)
 		writel(val, cp->regs + REG_PCS_MII_CTRL);
 
 		limit = STOP_TRIES;
-		while (limit-- > 0) {
+		while (--limit > 0) {
 			udelay(10);
 			if ((readl(cp->regs + REG_PCS_MII_CTRL) &
 			     PCS_MII_RESET) == 0)

index 61843fd..78f8cee 100644
@@ -79,7 +79,7 @@ static int reset_one_mii_phy(struct mii_phy* phy, int phy_id)
 
 	udelay(100);
 
-	while (limit--) {
+	while (--limit) {
 		val = __phy_read(phy, phy_id, MII_BMCR);
 		if ((val & BMCR_RESET) == 0)
 			break;

From: Roel Kluin <[email protected]>
Date: Sun, 01 Feb 2009 18:15:27 +0100

Also applied, thanks.