Beaglebone A4, u-boot ethernet phy question


I have some problems connecting a BeagleBone A4 to the network. I'm not
sure if I have all known issues fix so
this is merely for confirming I have everything applied which is needed
before digging deeper into this.

Some background:

- u-boot version is 2012.10-rc3
- R219 is removed
- Pin 10 on P9 measures 3.2V
- Linux kernel is taken from
"git://" with "git
checkout -f v3.2-staging" applied.
  I used the standard configuration coming with it (CONFIG_PREEMPT_NONE)
but changed:
     - ext4 support compiled into the kernel
     - power governor set to "ondemand"
- Distribution used is gentoo with latest stage3. Beside configuration
no additional packages have been installed yet.
- Network is configured statically with IP,Netmask, Broadcast and
default route

Network problems:
- can't ping the BeagleBone. The green LED indicates traffic is
recognized but no reply is sent back.

I wonder if the configuration for mode2 pin problem mentioned here

is present in u-boot 2012.10-rc3. I found this code in u-boot:

arch/arm/cpu/armv7/am33x/board.c in function "board_eth_init()":

       if (board_is_bone()) {
                writel(MII_MODE_ENABLE, &cdev->miisel);
                cpsw_slaves[0].phy_if = cpsw_slaves[1].phy_if =

which might indicate the configuration value is applied.

Is this the needed configuration or do I need to add some code here to
work around the Pin14/Pin15 problem?


Hi Thomas,

I see an issue like this intermittently, I currently have one bone out of service due to this problem. I have a bone on standby for cases like this, as to fix it I just leave it unplugged for an exenteded period of time, usually about a week. The only explanation I have for this is that the silicon gets into an odd state somewhere and it takes a full power down, with no residing current to clear whatever it is that is going wrong.

I would first suggest trying with the officially shipped sd card image, if it still doesn't work, leave it unplugged for a week and see if it springs back to life.


Hi Jack,

thanks for the reply. It seems this is an intermittent issue for me as well.
I started the bone today - no USB cable connected on the serial/FDTI
port and no ethernet cable connected either -,
plugged the cable in after the current consumption indicated the system
is idle and now ethernet connection works.

I'll see if this procedure will work 100% later this week.


Quite often mine will work for a couple of hours and then give up, keep me informed!