USB/Ethernet power down after boot

Hi all,

I’ve just bought a Beagleboard-xM. The board seems to work fine at boot, but after a couple of minutes after boot, USB host ports and Ethernet power down and it is impossible to raise them again without physical reboot of the board.

In detail, what happens is:

  1. when the board is booted, everything is fine: USB attached device like keyboard or mouse work, and Ethernet works (I can ping the board). The module smsc95xx is correctly loaded by kernel.

  2. After a time from approximately 2 to 4 min the kernel emits the following message on the console, and USB and Ethernet stop working. Also Ethernet leds shut down and there is no way to reactivate them, but rebooting the board removing power.

[ 88.825531] usb 1-2: USB disconnect, device number 2
[ 88.830780] usb 1-2.1: USB disconnect, device number 3
[ 88.836578] smsc95xx 1-2.1:1.0: eth0: unregister ‘smsc95xx’ usb-ehci-omap.0-2.1, smsc95xx USB 2.0 Ethernet
[ 88.857666] usb 1-2.4: USB disconnect, device number 4
[ 89.146179] usb 1-2: new high speed USB device number 5 using ehci-omap
[ 89.693023] usb 1-2: device not accepting address 5, error -71
[ 89.755554] hub 1-0:1.0: unable to enumerate USB device on port 2

  1. After that event, the board is still alive, since it is possible to login through RS232 port.

I’ve tried both the Angstrom version in the test microSD provided with the board and the latest version with kernel 3.0.17, but the problem is the same.

Looking through the forum, I initially thought that the problem may be related to a power supply issue, since I read of similar troubles related to insufficient input power to the board. So, I soldered a tip connector to a wire to power the board through my Kert stabilized power supply, which surely provides enough power. The problem repeats the same way. In addiction, using this supply I noted that when the problem occurs, the current drained drops immediately from about 0.6 A to 0.25 A. I don’t know if the current drop is a cause (not enough current → disable USB/Ethernet) or just a consequence (something disables USB/Ethernet, so power need lowers).

So, I’m not sure if this is a software issue or (as I suspect) an hardware problem. At least to understand if I have to send the board back to RMA or if I can fix the problem myself.

Davide Rondini

The reason the current drops is because those devices are being turned off. As they work intially, and stop later when they are turned off, it appears to me to be a SW issue. There is a pin that turns off the regulator and if that signal is changed via SW, then it will turn off.


The problem seems to be the same described in this thread, but for me the new kernel didn’t fix the problem: