[U-Boot] [PATCH] net: Use 0.5 sec timeout in miiphy_reset() instead of counting loop

[U-Boot] [PATCH] net: Use 0.5 sec timeout in miiphy_reset() instead of counting loop

[Stefan Roese]

This patch fixes a problem I've notived on a buggy PPC4xx system. This
system has problems with the PHY MDIO communication and seemed to be
stuck/crashed in miiphy_reset(). But degugging revealed, that the CPU
didn't crash, but "only" hung in this counting loop for about 2 minutes.

This patch now uses a real timeout of 0.5 seconds (as mentioned in the
comment in miiphy_reset).

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Ben Warren <biggerbadderben@gmail.com>
---
 common/miiphyutil.c |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/common/miiphyutil.c b/common/miiphyutil.c
index 196ef4a..856fbc7 100644
--- a/common/miiphyutil.c
+++ b/common/miiphyutil.c
@@ -293,7 +293,7 @@ int miiphy_info (char *devname, unsigned char addr, unsigned int *oui,
 int miiphy_reset (char *devname, unsigned char addr)
 {
 	unsigned short reg;
-	int loop_cnt;
+	int timeout = 500;
 
 	if (miiphy_read (devname, addr, PHY_BMCR, &reg) != 0) {
 		debug ("PHY status read failed\n");
@@ -311,13 +311,13 @@ int miiphy_reset (char *devname, unsigned char addr)
 	 * auto-clearing).  This should happen within 0.5 seconds per the
 	 * IEEE spec.
 	 */
-	loop_cnt = 0;
 	reg = 0x8000;
-	while (((reg & 0x8000) != 0) && (loop_cnt++ < 1000000)) {
-		if (miiphy_read (devname, addr, PHY_BMCR, &reg) != 0) {
-			debug ("PHY status read failed\n");
-			return (-1);
+	while (((reg & 0x8000) != 0) && timeout--) {
+		if (miiphy_read(devname, addr, PHY_BMCR, &reg) != 0) {
+			debug("PHY status read failed\n");
+			return -1;
 		}
+		udelay(1000);
 	}
 	if ((reg & 0x8000) == 0) {
 		return (0);
-- 
1.6.6.1

[U-Boot] [PATCH] net: Use 0.5 sec timeout in miiphy_reset() instead of counting loop

[Ladislav Michl]

On Tue, Feb 02, 2010 at 01:43:48PM +0100, Stefan Roese wrote:
> This patch fixes a problem I've notived on a buggy PPC4xx system. This
> system has problems with the PHY MDIO communication and seemed to be
> stuck/crashed in miiphy_reset(). But degugging revealed, that the CPU
> didn't crash, but "only" hung in this counting loop for about 2 minutes.
> 
> This patch now uses a real timeout of 0.5 seconds (as mentioned in the
> comment in miiphy_reset).

Well, so this also seems to fix watchdog reseting issue on few boards I see
there (udelay triggers watchdog). Thanks for fixing that!

	ladis

[U-Boot] [PATCH] net: Use 0.5 sec timeout in miiphy_reset() instead of counting loop

[Ben Warren]

Stefan,

On 2/2/2010 4:43 AM, Stefan Roese wrote:
> This patch fixes a problem I've notived on a buggy PPC4xx system. This
> system has problems with the PHY MDIO communication and seemed to be
> stuck/crashed in miiphy_reset(). But degugging revealed, that the CPU
> didn't crash, but "only" hung in this counting loop for about 2 minutes.
>
> This patch now uses a real timeout of 0.5 seconds (as mentioned in the
> comment in miiphy_reset).
>
> Signed-off-by: Stefan Roese<sr@denx.de>
> Cc: Ben Warren<biggerbadderben@gmail.com>
> ---
>   common/miiphyutil.c |   12 ++++++------
>   1 files changed, 6 insertions(+), 6 deletions(-)
>    
Applied to net repo.

thanks,
Ben