[PATCH] Re: ep93xx_eth PHY problems
From: Oliver Martin <hidden>
Date: 2008-03-21 19:22:18
Am Tue, 04 Mar 2008 14:02:15 +0100 schrieb Oliver Martin [off-list ref]:
Now I'm having different problems: When auto-negotiation is enabled, it sometimes randomly changes the link state: PHY: 0:01 - Link is Down PHY: 0:01 - Link is Up - 100/Full
I've found at least one part of the problem. The MDIO clock divisor wasn't set again after the reset in ep93xx_start_hw. It was left at the default, resulting in a 12.5 MHz clock, which the PHY (Micrel KSZ8721BL) didn't like too much. Calling ep93xx_mdio_reset after the reset fixed it, the link is now perfectly stable in auto-negotiation mode. There still seems to be another bug with auto-negotiation disabled: It doesn't switch to 1000 Mbps any more, but most times it doesn't stay in the intended configuration either. I haven't done any extensive testing of this yet, though. Signed-off-by: Oliver Martin <redacted>
--- linux-2.6.24-phy/drivers/net/arm/ep93xx_eth.c.orig 2008-03-19 15:18:29.000000000 +0100
+++ linux-2.6.24-phy/drivers/net/arm/ep93xx_eth.c 2008-03-19 15:43:44.000000000 +0100@@ -535,6 +535,22 @@ err: return 1; } +static int ep93xx_mdio_reset(struct mii_bus *bus) +{ + struct ep93xx_priv *ep = bus->priv; + + u32 selfctl = rdl(ep, REG_SELFCTL); + + selfctl &= ~(REG_SELFCTL_MDCDIV_MSK | REG_SELFCTL_PSPRS); + + selfctl |= (ep->mdc_divisor - 1) << REG_SELFCTL_MDCDIV_OFS; + selfctl |= REG_SELFCTL_PSPRS; + + wrl(ep, REG_SELFCTL, selfctl); + + return 0; +} + static int ep93xx_start_hw(struct net_device *dev) { struct ep93xx_priv *ep = netdev_priv(dev);
@@ -553,6 +569,9 @@ static int ep93xx_start_hw(struct net_de return 1; } + /* The reset cleared REG_SELFCTL, so set the MDC divisor again */ + ep93xx_mdio_reset(&ep->mii_bus); + /* Receive descriptor ring. */ addr = ep->descs_dma_addr + offsetof(struct ep93xx_descs, rdesc); wrl(ep, REG_RXDQBADD, addr);
@@ -776,22 +795,6 @@ static int ep93xx_mdio_write(struct mii_ return 0; } -static int ep93xx_mdio_reset(struct mii_bus *bus) -{ - struct ep93xx_priv *ep = bus->priv; - - u32 selfctl = rdl(ep, REG_SELFCTL); - - selfctl &= ~(REG_SELFCTL_MDCDIV_MSK | REG_SELFCTL_PSPRS); - - selfctl |= (ep->mdc_divisor - 1) << REG_SELFCTL_MDCDIV_OFS; - selfctl |= REG_SELFCTL_PSPRS; - - wrl(ep, REG_SELFCTL, selfctl); - - return 0; -} - static void ep93xx_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info) {