Re: [PATCH] Re: ep93xx_eth PHY problems
From: Lennert Buytenhek <hidden>
Date: 2008-09-16 12:51:26
On Sun, Sep 14, 2008 at 02:11:10PM +0200, Oliver Martin wrote:
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Am Tue, 04 Mar 2008 14:02:15 +0100 schrieb Oliver Martin [off-list ref]:quoted
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/FullI'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>Testing feedback? Lennert ack?We're currently using a variation of my original patch, which didn't handle ifdown correctly (there's a similar reset there). With the current setup, everything seems stable, but we still have some rather hackish workarounds for the original issue in our startup scripts. I don't have the hardware right now, but we'll specifically test without them both with and without auto-negotiation next week and report the results.
OK, can you provide a commit message for this so that I can add it to http://git.wantstofly.org/?p=ep93xx_eth.git/.git;a=summary and ask Jeff to pull it?
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Index: linux-2.6.26/drivers/net/arm/ep93xx_eth.c ===================================================================--- linux-2.6.26.orig/drivers/net/arm/ep93xx_eth.c 2008-07-25 03:13:33.000000000 +0200 +++ linux-2.6.26/drivers/net/arm/ep93xx_eth.c 2008-07-25 03:14:52.000000000 +0200@@ -535,6 +535,22 @@ 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 @@ 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);@@ -625,6 +644,9 @@ if (i == 10) printk(KERN_CRIT DRV_MODULE_NAME ": hw failed to reset\n"); + + /* The reset cleared REG_SELFCTL, so set the MDC divisor again */ + ep93xx_mdio_reset(&ep->mii_bus); } static int ep93xx_open(struct net_device *dev)@@ -776,22 +798,6 @@ 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) {