Re: imx6q: force 100 mbps network

[Gary Thomas <gary@mlbassoc.com>]

On 2014-02-26 06:12, Prasant J wrote:
> 
> On Wed, Feb 26, 2014 at 5:59 PM, Prasant J <pj0585@gmail.com <mailto:pj0585@gmail.com>> wrote:
> 
> 
> 
>     On Wed, Feb 26, 2014 at 5:37 PM, Gary Thomas <gary@mlbassoc.com <mailto:gary@mlbassoc.com>> wrote:
> 
>         On 2014-02-26 05:03, Prasant J wrote:
>         > Hi,
>         >
>         > I'm using linux-3.0.35 on my custom hardware (uses imx6 quad) based on sabresd platform. I'm using yocto root filesystem (this is a soft float build).
>         >
>         > I want to force my system to use 100 mbps ethernet speed even if the network supports 1000 mbps link. How can I enable this ?
>         >
>         > My custom hardware uses Micrel's Gigabit Ethernet PHY KSZ9021RNI.
>         >
>         > I can change the network speed (by ssh-ing into the linux system) using:
>         > ethtool -s eth0 autoneg off speed 100
>         > but I want network speed of 100 mbps when network is initialized during startup.
>         >
>         > Any inputs will be of help.
> 
>         If you are using init-ifupdown to manage the network, you can
>         change /etc/network/interfaces to look something like this:
> 
>         auto eth0
>         iface eth0 inet dhcp
>               pre-up ethtool -s eth0 speed 100 duplex full autoneg off
> 
> 
>     Hi Gary,
> 
>     That will help.
>     I guess the same will work when I configure staticip by modifying the /etc/network/interfaces file.
> 
>     I will try this one. Thanks once again!
> 
> 
> This did not work :(
> 
> This is from the serial log:
> 
> Configuring network interfaces... Cannot get current device settings: No such device
>   not setting speed
>   not setting duplex
>   not setting autoneg
> 
>  
> I guess before ifup is executed, ethtool cannot get eth0.
> 
> Any other suggestions?

Just add another line to force the network up.  I just ran this on
my SabreLite and it worked fine:

# Wired or wireless interfaces
auto eth0
iface eth0 inet dhcp
      pre-up ifconfig eth0 up
      pre-up ethtool -s eth0 speed 10 duplex full autoneg on

I chose 10Mbps so I could make sure the settings were from what
I set, not the automatic ones.

-- 
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Gary Thomas                 |  Consulting for the
MLB Associates              |    Embedded world
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