From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 497A7B7085 for ; Fri, 17 Jul 2009 22:27:12 +1000 (EST) Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.10]) by ozlabs.org (Postfix) with ESMTP id 85A4CDDD0B for ; Fri, 17 Jul 2009 22:27:11 +1000 (EST) From: Wolfgang Denk To: linuxppc-dev@ozlabs.org Subject: [PATCH 2/2 v3] MPC52xx FEC: be more conservative when setting MII_SPEED register Date: Fri, 17 Jul 2009 14:27:08 +0200 Message-Id: <1247833628-15952-2-git-send-email-wd@denx.de> In-Reply-To: <1247780546-4426-1-git-send-email-wd@denx.de> References: <1247780546-4426-1-git-send-email-wd@denx.de> Cc: netdev@vger.kernel.org, Wolfgang Denk List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This patch adds error checking and prevents clobbering unrelated bits (reserved bits or the DIS_PREAMBLE bit) when writing the MII_SPEED register on MPC52xx systems. Signed-off-by: Wolfgang Denk Cc: Grant Likely Cc: Kumar Gala Cc: --- v3: - use maximum divider in case MPC512x IPS clock is unknown drivers/net/fec_mpc52xx.c | 2 +- drivers/net/fec_mpc52xx_phy.c | 23 ++++++++++++++++++++--- 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/drivers/net/fec_mpc52xx.c b/drivers/net/fec_mpc52xx.c index cc78633..b69d440 100644 --- a/drivers/net/fec_mpc52xx.c +++ b/drivers/net/fec_mpc52xx.c @@ -639,7 +639,7 @@ static void mpc52xx_fec_hw_init(struct net_device *dev) /* set phy speed. * this can't be done in phy driver, since it needs to be called * before fec stuff (even on resume) */ - out_be32(&fec->mii_speed, priv->mdio_speed); + clrsetbits_be32(&fec->mii_speed, 0x7E, priv->mdio_speed); } /** diff --git a/drivers/net/fec_mpc52xx_phy.c b/drivers/net/fec_mpc52xx_phy.c index 31e6d62..d3537e1 100644 --- a/drivers/net/fec_mpc52xx_phy.c +++ b/drivers/net/fec_mpc52xx_phy.c @@ -70,7 +70,7 @@ static int mpc52xx_fec_mdio_probe(struct of_device *of, struct mpc52xx_fec_mdio_priv *priv; struct resource res = {}; int err; - int i; + int i, clock, speed; bus = mdiobus_alloc(); if (bus == NULL) @@ -105,8 +105,25 @@ static int mpc52xx_fec_mdio_probe(struct of_device *of, dev_set_drvdata(dev, bus); /* set MII speed */ - out_be32(&priv->regs->mii_speed, - ((mpc5xxx_get_bus_frequency(of->node) >> 20) / 5) << 1); + clock = mpc5xxx_get_bus_frequency(of->node); + if (!clock) { + /* Use maximum divider if clock is unknown */ + dev_err(&of->dev, "could not determine IPB clock\n"); + clock = 0x3F * 5000000; + } + + /* + * Scale for a MII clock <= 2.5 MHz + * Note that only 6 bits (25:30) are available for MII speed. + */ + speed = (clock + 4999999) / 5000000; + if (speed > 0x3F) { + speed = 0x3F; + dev_err(&of->dev, "MII clock (%d Hz) exceeds max (2.5 MHz)\n", + clock / speed); + } + + clrsetbits_be32(&priv->regs->mii_speed, 0x7E, speed << 1); err = of_mdiobus_register(bus, np); if (err) -- 1.6.0.6