From de339c2aa7fea18410b1abeab5674bfbd4073a63 Mon Sep 17 00:00:00 2001 From: Trent Piepho Date: Wed, 19 Nov 2008 15:52:41 -0800 Subject: [PATCH] phylib: Fix auto-negotiation restart avoidance A previous patch, 51e2a3846eab18711f4eb59cd0a4c33054e2980a, made genphy_config_aneg() not restart aneg by calling genphy_restart_aneg() if the advertisement hadn't changed. But, genphy_restart_aneg() doesn't just restart aneg, it may also *enable* aneg or un-isolate the PHY from the MII (those functions are controlled by the same register). The code to avoid calling genphy_restart_aneg() didn't consider this. So, modify genphy_config_aneg() to also check if the PHY needs to have aneg enabled or be un-isolated before deciding not to restart aneg. This caused a problem with certain Davicom PHYs, as that driver isolates the PHY (why?) before calling genphy_config_aneg() and expects the PHY to be un-isolated by that function. Signed-off-by: Trent Piepho Reported-by: Scott Wood Signed-off-by: David S. Miller --- drivers/net/phy/phy_device.c | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c index 8fb1fac..55bc24b 100644 --- a/drivers/net/phy/phy_device.c +++ b/drivers/net/phy/phy_device.c @@ -564,20 +564,32 @@ EXPORT_SYMBOL(genphy_restart_aneg); */ int genphy_config_aneg(struct phy_device *phydev) { - int result = 0; + int result; - if (AUTONEG_ENABLE == phydev->autoneg) { - int result = genphy_config_advert(phydev); + if (AUTONEG_ENABLE != phydev->autoneg) + return genphy_setup_forced(phydev); + + result = genphy_config_advert(phydev); + + if (result < 0) /* error */ + return result; - if (result < 0) /* error */ - return result; + if (result == 0) { + /* Advertisment hasn't changed, but maybe aneg was never on to + * begin with? Or maybe phy was isolated? */ + int ctl = phy_read(phydev, MII_BMCR); + + if (ctl < 0) + return ctl; + + if (!(ctl & BMCR_ANENABLE) || (ctl & BMCR_ISOLATE)) + result = 1; /* do restart aneg */ + } - /* Only restart aneg if we are advertising something different - * than we were before. */ - if (result > 0) - result = genphy_restart_aneg(phydev); - } else - result = genphy_setup_forced(phydev); + /* Only restart aneg if we are advertising something different + * than we were before. */ + if (result > 0) + result = genphy_restart_aneg(phydev); return result; } -- 2.7.4