Ubiquiti EdgeRouter Lite works multi-user with -CURRENT.

[Joe Holden]

Juli Mallett wrote:
> On Thu, May 23, 2013 at 10:43 AM, Warner Losh <imp at bsdimp.com> wrote:
>> On May 23, 2013, at 5:42 AM, Milan Obuch wrote:
>>
>>> On Wed, 22 May 2013 22:59:36 -0700, Juli Mallett <jmallett at FreeBSD.org>
>>> wrote:
>>>
>>>> On Wed, May 22, 2013 at 10:55 PM, Milan Obuch <freebsd-mips at dino.sk>
>>>> wrote:
>>>>> Yes, you are right - now I checked with octe0 connected to 100
>>>>> megabit switch and it initializes correctly when booting. When I
>>>>> plug gigabit card now instead, it does not work - no communication
>>>>> on interface. Even if I do ifconfig octe down/ifconfig octe up, it
>>>>> does not transmit/receive packets. So I think problem is phy link
>>>>> speed change on live system. Reboot in this case is a big hackish
>>>>> 'workaround' for now - good for tests, not yet fully for real work
>>>>> (but if you know there will be no link speed change it is OK).
>>>> The link state management is crappy, I concede.  I kept it as it was
>>>> in the Linux code because I wanted to be able to merge driver updates
>>>> from Cavium, but that's not viable given how much they've changed the
>>>> driver anyway.  How long did you wait?  It could take between 5
>>>> seconds and a minute for link state to change at runtime in my
>>>> experience.  I looked into making this faster at one point and even
>>>> had a patch, but don't know where it is or why I didn't commit it.
>>>>
>>>> If either of you wants to take a crack at fixing it I can explain what
>>>> to instrument in the driver and what's likely to be the problem.  Let
>>>> me know if that might be useful.  (Apologies of the latency is high on
>>>> my responding.)
>>>>
>>>> Thanks,
>>>> Juli.
>>> If you have any patches to test, some how-to what to look for and try
>>> to change etc... I could try to work a bit on it. It seems there is not
>>> much freely available resources for Cavium CPUs (I found cnusers.org is
>>> of interest, it seems) so some leading will be good to have :)
>> cnusers is Cavium's release vehicle for GPL'd  code... There's lots of code available for the Cavium processor, but the docs are kinda hard to get a hold of...
> 
> And I'd add that the code is fairly complete and heavily-documented
> (well-documented is a different question; it can be a little obtuse.)
> Some people find code as useful or more useful than documentation, and
> in that case the code Cavium puts out is useful-enough, although most
> of it is already in src/sys/contrib/octeon-sdk, although I sometimes
> have found looking at the U-Boot code helpful, too.  I've never found
> Cavium's documentation to be as useful as their code, but that's just
> me.
> 
> In this case, I'd say that the most useful thing to instrument is
> likely cvm_do_timer in sys/mips/cavium/octe/ethernet.c.  I'd suggest
> first changing:
> 
> 138 if (priv->need_link_update) {
> 139 updated++;
> 140 taskqueue_enqueue(cvm_oct_link_taskq, &priv->link_task);
> 141 }
> 
> To be just
> 
> taskqueue_enqueue(cvm_oct_link_taskq, &priv->link_task);
> 
> If that helps, then I think there's two things that need to be done:
> 
> First, we shouldn't use slow-polling to do that anyway, we should just
> call taskqueue_enqueue whenever we set need_link_update to 1 if it was
> not 1 already.  This is mostly a structural-cosmetic kind of thing.
> 
> Second, cvm_oct_rgmii_poll in ethernet-rgmii.c is probably wrong in
> some way.  Instrumenting it to print out the various register states
> and see if a human can see link status changes even if it can't may be
> helpful.  Alternately, you may want/need to look at UBNT's patches for
> the ERLite.  I may have missed some change it requires (if so, please
> let me know rather than just committing the changes; I've tried to
> isolate and keep minimal vendor-specific changes since we support so
> many vendors; not every vendor shares my concern, and a lot of them
> make the code too complex, or other things we don't want.)  It could
> be just a matter of not using/programming/undermining RGMII in the way
> the hardware wants, or it could be that we need a PHY driver or
> something else.
> 
> Actually, looking at how the hardware is set up, it looks like we
> should be using a PHY driver already, so it may be that none of that
> is helpful (since the internal link status management is only used if
> we don't have a PHY) and the real fix needs to happen in atphy.c.  Or
> that for this hardware we should just use the internal link status
> management rather than using the PHY.
> 
> Thanks,
> Juli.

Yeah it doesn't appear to just be a delay as the link still hasn't 
started working since this morning - I did note that the atheros phy 
stuff in the UBNT release identifies itself as a modified ubnt one, so 
there may well be some slight change that needs doing - well outside of 
the scope of my skills though :(