From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Guo Subject: Re: [PATCH 3/4] net/fec: set phy_speed to the optimal frequency 2.5 MHz Date: Tue, 20 Sep 2011 10:57:01 +0800 Message-ID: <20110920025700.GE28084@S2100-06.ap.freescale.net> References: <1316346852-17090-1-git-send-email-shawn.guo@linaro.org> <1316346852-17090-4-git-send-email-shawn.guo@linaro.org> <4E77C4A2.1060802@boundarydevices.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Cc: Shawn Guo , , "David S. Miller" , , To: Troy Kisky Return-path: Received: from db3ehsobe001.messaging.microsoft.com ([213.199.154.139]:3977 "EHLO DB3EHSOBE001.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753586Ab1ITCtx (ORCPT ); Mon, 19 Sep 2011 22:49:53 -0400 Content-Disposition: inline In-Reply-To: <4E77C4A2.1060802@boundarydevices.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Sep 19, 2011 at 03:39:30PM -0700, Troy Kisky wrote: > On 9/18/2011 4:54 AM, Shawn Guo wrote: > >With the unnecessary 1 bit left-shift on fep->phy_speed during the > >calculation, the phy_speed always runs at the half frequency of the > >optimal one 2.5 MHz. > > > >The patch removes that 1 bit left-shift to get the optimal phy_speed. > > > >Signed-off-by: Shawn Guo > >--- > > drivers/net/fec.c | 2 +- > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > >diff --git a/drivers/net/fec.c b/drivers/net/fec.c > >index 5ef0e34..04206e4 100644 > >--- a/drivers/net/fec.c > >+++ b/drivers/net/fec.c > >@@ -1007,7 +1007,7 @@ static int fec_enet_mii_init(struct platform_device *pdev) > > /* > > * Set MII speed to 2.5 MHz (= clk_get_rate() / 2 * phy_speed) > > */ > >- fep->phy_speed = DIV_ROUND_UP(clk_get_rate(fep->clk), 5000000)<< 1; > >+ fep->phy_speed = DIV_ROUND_UP(clk_get_rate(fep->clk), 5000000); > > writel(fep->phy_speed, fep->hwp + FEC_MII_SPEED); > > > > fep->mii_bus = mdiobus_alloc(); > Do you need to round up to an even value? Is the hardware > documentation wrong? The round up is something existed, and the patch does not touch that part. > Does this need a quirk? What boards has this been verified to fix? > I tested this on i.mx28, i.mx53 and i.mx6q. Do you see problem on your platform? -- Regards, Shawn