BeagleBone Rev. A4 ethernet issue

I can confirm, that ethernet works after reboot on my rev A4 board.
I've also noticed, that issue is not present if you connect the board
to a 10 mbps ethernet hub. In that case ethernet works every time.

Boris

Thanks for the suggestion. I eventually decided to smash the R219 and
ethnet works even since.

Sounds good. I hope we can get a SW fix soon!

Gerald

I can also confirm, that ethernet works only when typed "reboot" after
power on boot on my rev. A4 bbone :frowning:

Just got an A.4 board and spent an hour fiddling with the Ethernet.
Reboot did not do it. However, snapping off the resistor seems to have
fixed it.

At least I am able to see the IDE and ping. Haven't tried everything
but that should be it.

Al W.
http://www.ddj.com/embedded

For now at least. popping the resistor is going to be the recommended fix.

Gerald

Hi,
I do not mean to rush, but is there any ETA on this SW fix to have a
rough idea if I should consider removing R219 or preferably wait?
Are you really positive that if something goes wrong removing the
R219, it will not void the warranty (possible to return/exchange the
board) ?
Thanks
Kevin

I have no ETA on the SW fixed. So far everyone is baffeled. It may end up being something in the PHY itself. I would pop the resitor,. It will not affect the warranty.

http://circuitco.com/support/index.php?title=BeagleBone#Known_Issues

Gerald

Thanks a lot for your swift answer. I'll try to pop the resistor then!
Kevin

I attest that removing R219 fixes it.

This only confirms the old embedded theory that hardware problems have
software
solutions and vice versa :slight_smile:

Actually, it is not a fix. Ethernet does not work in u-boot even with
R219 removed.

It does resolve the problem once the kernel is up and running though.

Ned

Not working in UBoot is definitely a SW question.

Gerald

are you turning dcache off before trying it?

I'm surprised that you are recommending that users pop the resistor
off with an icepick. Aren't you concerned that the soldering pads
will come off with the resistor if they don't use an iron? I have
seen this happen unintentionally many times when a part is snagged
while sliding a board into a chassis. The part comes off, but the
pads come off as well. Then it is a major job ever putting the part
back on. Also this can tear the attached trace off all the way to the
next via.

Are the BB boards made differently so that the copper traces are glued
better and stronger than the solder joints? Even the process of
crushing the part with pliers can result in damaged pads.

Rick

If the pad comes off that is fine because the removal of the resistor is permanent. In other words it will not be reinstalled at a later date on this board. The next revision of the board, A5 will not have the resistor installed at all. Then we have a REV A6 coming in a month or two which will have it on there plus another change we are making.

Gerald

R219 mounting is quite interesting ....
my SMD (de)soldering tool blew away R16 before R219 gave way :slight_smile:

Well, I guess the low tech way is the easy way. The Yellow LED will be off when running at 100M, so removing R16 will not hurt anything. You will never miss it!

Gerald

Just got my A4 and had the same issue. I snapped off R219 but it
doesn't seem to have helped. Most of the time eth0 comes up in the
ifconfig section of info.txt -- but not always. Sometimes it's just
lo. And when it does show up, it never seems to obtain a DHCP
address.

I haven't yet set up the USB net connection, and I suppose that will
suffice, but it's a bit disappointing to have taken a drastic fix like
snapping off a component and still not have a fix.

This fix is required. Sounds like you may have another issue with your setup or configuration, but without this drastic fix I can promise, it will not work. So the drastic fix is not all that drastic.

Gerald

I used some 470R from an old hard disk board so it's back to yellow :slight_smile:

Turning the dcache really helps, now it works in u-boot too.
So the sequence in u-boot would be:

dcache off
tftp ..............
dcache on

Tried it a dozen times without a glitch.

Ned