From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from www84.your-server.de (www84.your-server.de [213.133.104.84]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 15DDBB7D8F for ; Mon, 1 Mar 2010 10:00:43 +1100 (EST) Subject: [PATCH] fix PHY polling system blocking From: Stefani Seibold To: linux-kernel , linuxppc-dev , Thomas Gleixner Content-Type: text/plain; charset="ISO-8859-15" Date: Sun, 28 Feb 2010 23:39:09 +0100 Message-ID: <1267396749.20057.62.camel@wall-e> Mime-Version: 1.0 List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This patch fix the PHY poller, which can block the whole system. On a Freescale PPC 834x this result in a delay of 450 us due the slow communication with the PHY chip. For PHY chips without interrupts, the status of the ethernet will be polled every 2 sec. The poll function will read some register of the MII PHY. The time between the sending the MII_READ_COMMAND and receiving the result is more the 100 us on a PPC 834x. The patch modifies the poller a lit bit. Only a link status state change will result in a successive detection of the connection type. The poll cycle on the other hand will be increased to every seconds. Together this patch will prevent a blocking of nearly 400 us every two seconds of the whole system on a PPC 834x. The patch is against kernel 2.6.33. Please merge it. Signed-off-by: Stefani Seibold --- phy.c | 5 ++--- phy_device.c | 12 +++++++++--- 2 files changed, 11 insertions(+), 6 deletions(-) diff -u -N -r -p linux-2.6.33.orig/drivers/net/phy/phy.c linux-2.6.33/drivers/net//phy/phy.c --- linux-2.6.33.orig/drivers/net/phy/phy.c 2010-02-24 19:52:17.000000000 +0100 +++ linux-2.6.33/drivers/net//phy/phy.c 2010-02-28 22:53:14.725464101 +0100 @@ -871,9 +871,8 @@ void phy_state_machine(struct work_struc case PHY_RUNNING: /* Only register a CHANGE if we are * polling */ - if (PHY_POLL == phydev->irq) - phydev->state = PHY_CHANGELINK; - break; + if (PHY_POLL != phydev->irq) + break; case PHY_CHANGELINK: err = phy_read_status(phydev); diff -u -N -r -p linux-2.6.33.orig/drivers/net/phy/phy_device.c linux-2.6.33/drivers/net//phy/phy_device.c --- linux-2.6.33.orig/drivers/net/phy/phy_device.c 2010-02-24 19:52:17.000000000 +0100 +++ linux-2.6.33/drivers/net//phy/phy_device.c 2010-02-28 22:53:14.726464145 +0100 @@ -161,7 +161,7 @@ struct phy_device* phy_device_create(str dev->speed = 0; dev->duplex = -1; dev->pause = dev->asym_pause = 0; - dev->link = 1; + dev->link = 0; dev->interface = PHY_INTERFACE_MODE_GMII; dev->autoneg = AUTONEG_ENABLE; @@ -694,10 +694,16 @@ int genphy_update_link(struct phy_device if (status < 0) return status; - if ((status & BMSR_LSTATUS) == 0) + if ((status & BMSR_LSTATUS) == 0) { + if (phydev->link==0) + return 1; phydev->link = 0; - else + } + else { + if (phydev->link==1) + return 1; phydev->link = 1; + } return 0; }