[U-Boot] [PATCH] net: phy: do not read configuration register on reset

[Stefan Agner]

When doing a software reset, the reset flag should be written without
other bits set. Writing the current state will lead to restoring the
state of the PHY (e.g. Powerdown), which is not what is expected from
a software reset.

Signed-off-by: Stefan Agner <stefan at agner.ch>
---
This lead to the PHY staying powered down on a reboot when using a
Micrel PHY and not using hardware reset...

It also aligns with the behavior of Linux:
http://lxr.free-electrons.com/source/drivers/net/phy/phy_device.c#L1122

--
Stefan

 drivers/net/phy/phy.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 51b5746..ef9f13b 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -717,15 +717,7 @@ int phy_reset(struct phy_device *phydev)
 	}
 #endif
 
-	reg = phy_read(phydev, devad, MII_BMCR);
-	if (reg < 0) {
-		debug("PHY status read failed\n");
-		return -1;
-	}
-
-	reg |= BMCR_RESET;
-
-	if (phy_write(phydev, devad, MII_BMCR, reg) < 0) {
+	if (phy_write(phydev, devad, MII_BMCR, BMCR_RESET) < 0) {
 		debug("PHY reset failed\n");
 		return -1;
 	}
@@ -738,6 +730,7 @@ int phy_reset(struct phy_device *phydev)
 	 * auto-clearing).  This should happen within 0.5 seconds per the
 	 * IEEE spec.
 	 */
+	reg = phy_read(phydev, devad, MII_BMCR);
 	while ((reg & BMCR_RESET) && timeout--) {
 		reg = phy_read(phydev, devad, MII_BMCR);
 
-- 
2.6.3