From: Troy Kisky <troy.kisky@boundarydevices.com>
To: Shawn Guo <shawn.guo@linaro.org>
Cc: 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: Mon, 19 Sep 2011 15:39:30 -0700 [thread overview]
Message-ID: <4E77C4A2.1060802@boundarydevices.com> (raw)
In-Reply-To: <1316346852-17090-4-git-send-email-shawn.guo@linaro.org>
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?
Does this need a quirk? What boards has this been verified to fix?
Thanks
Troy
next prev parent reply other threads:[~2011-09-19 22:39 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 [this message]
2011-09-20 2:57 ` Shawn Guo
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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