[OpenWrt-Devel] Ethernet problem with R8000

Ian Kent raven at themaw.net
Wed Mar 4 06:35:37 EST 2015

On Wed, 2015-03-04 at 10:29 +0000, Conor O'Gorman wrote:
> On 04/03/15 05:29, Ian Kent wrote:
> > On Sat, 2015-02-28 at 23:07 +0800, Ian Kent wrote:
> >> The only things I can say for sure are, packets sent are seen by the
> >> bgmac driver and the driver gets a transmit completion interrupt which
> >> it processes. However, no packets is seen coming from the router switch
> >> port. Similarly no interrupts are seen by the driver for incoming
> >> packets at all.

Thanks for giving this some thought.

> Can you access switch chip registers?

Reckon so.

This device uses the bgmac driver.

What I've looked at so far is the DMA state and error registers and how
the Descriptor stop index (last posted descriptor for transmit, etc)
registers change for the DMA controller transmit and receive queues (see
below link). I've also done some printks to check some key values in the
driver and that looks ok too.

All looks as it should in that no error bits are set and the status
register shows the transmit and receive functions are enabled and AFAICS
the magic to poke the DMA engine is being done as it should.

It's puzzling.

Truth is I can't find anything that looks even a little wrong comparing
it to the router GPL source code and the brcmfmac DMA code referenced in
the link blow.

It's even stranger that network packets pass through the router when I
have a machine plugged into a port and into the network on another port,
just nothing ever passes from the router to the network and visa versa.

> There may be counters in there, that will indicate if packets are making 
> it that far, in or out. You may see counters indicating errors. You 
> might be able to work out the arangement of ports from that info.
> You may have to configure some of the switch registers to get the 
> correct arrangement of the ports and/or vlan settings.

Haven't seen counters as such.

There are a bunch of counters listed in the b53 switch driver (mib
entries, but I haven't checked the device registers actually hold these
values) that essentially reflect what I'm seeing but don't offer much

It would be good if someone could identify devices using bcm53xx that
are known to work and, if available point to a boot log.

And in case anyone is interested my most recent R8000 boot log is here:

But there are a bunch of other registers, maybe I should go hunting ....

I'm working from this http://bcm-v4.sipsolutions.net/mac-gbit/Registers
and this for the DMA

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