From: Shawn Guo <shawn.guo@freescale.com>
To: Troy Kisky <troy.kisky@boundarydevices.com>
Cc: Shawn Guo <shawn.guo@linaro.org>, <netdev@vger.kernel.org>,
"David S. Miller" <davem@davemloft.net>,
<linux-arm-kernel@lists.infradead.org>, <patches@linaro.org>
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 [thread overview]
Message-ID: <20110920025700.GE28084@S2100-06.ap.freescale.net> (raw)
In-Reply-To: <4E77C4A2.1060802@boundarydevices.com>
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<shawn.guo@linaro.org>
> >---
> > 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
next prev parent reply other threads:[~2011-09-20 2:49 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-18 11:54 [PATCH 0/4] add fec support for imx6q Shawn Guo
2011-09-18 11:54 ` [PATCH 1/4] net/fec: change phy-reset-gpio request warning to debug message Shawn Guo
2011-09-18 11:54 ` [PATCH 2/4] net/fec: fix fec1 check in fec_enet_mii_init() Shawn Guo
2011-09-18 11:54 ` [PATCH 3/4] net/fec: set phy_speed to the optimal frequency 2.5 MHz Shawn Guo
2011-09-19 22:39 ` Troy Kisky
2011-09-20 2:57 ` Shawn Guo [this message]
2011-09-20 20:05 ` Troy Kisky
2011-09-20 20:10 ` Troy Kisky
2011-09-20 7:50 ` Lothar Waßmann
2011-09-20 8:14 ` Shawn Guo
2011-09-20 19:11 ` David Miller
2011-09-18 11:54 ` [PATCH 4/4] net/fec: add imx6q enet support Shawn Guo
2011-09-18 18:09 ` Francois Romieu
2011-09-19 9:08 ` Shawn Guo
2011-09-20 19:08 ` [PATCH 0/4] add fec support for imx6q David Miller
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