[U-Boot-Users] ethact, ethprim and NET_MULTI

vb vb at vsbe.com
Fri Mar 9 23:49:27 CET 2007


what happens if all interfaces are failing - does it come back to
ethprime after trying them all and stops or does it keep trying until
stopped by the operator with an arbitrary interface as the current

That seemed to have happened to me: I tried using an interface, it did
not work, I went to see what happened, turned out the hub was down,
but after I brought the hub back online the thing still didn't work -
why - another interface became "current"!

Also, in some situations it is harmful to expose internal IP addresses
on an external network - but u-boot would never have a second though
about it :-)


On 3/9/07, Wolfgang Denk <wd at denx.de> wrote:
> In message <f608b67d0703090925v1714b02cm78ea07f8a8090ec2 at mail.gmail.com> you wrote:
> >
> > > Redundancy is useless? Maybe for you. Others pay alot of money for it.
> >
> > Hey Wolfgang, let's not get personal here, it's just business :-)
> I did not intend to get personal. I just tried to explicate my
> position.
> > I appreciate your point, *in certain setups* it is quite advantageous
> > to be able to try using a different interface.
> And I agree that in certain setups it may be not beneficial, but on
> the other hand I don't see why it would be harmful there.
> > But in some other setups (let's say there is a system with a
> > controller with two interfaces - once serving the external port, and
> > another one serving the backplane) it is completely pointless to try
> > to say tftpboot off any other interface but the external port.
> OK. So when does it hurt you? You define ethprime  such  that  U-Boot
> will  start  using  the  correct  interface. If you command U-Boot to
> perform a network download it will try doing this, using the  correct
> interface.  If  your  network  and  your  servers  are  OK, this will
> succeed. Fine. If your network connection or your servers  have  some
> temporary  glitches,  this  should  be  handled gracefully by U-Boots
> retry mechanism. So this situation is handled on, too. Only  if  your
> network  connection  and/or  your  servers are inoperative for a long
> time then U-Boot will try and switch interfaces, which will not  help
> in  your  setup.  But  then  -  what  sort of damage is done? If your
> network resp. server did not work for such a long time as the  U-Boot
> timeout,  then  chances  that they would start working after this are
> not exactly high. Continueing to try loading from  the  non-operative
> interface  is  not much better that trying to download from the other
> interface which does not work either. So what do you lose?
> Best regards,
> Wolfgang Denk
> --
> DENX Software Engineering GmbH, HRB 165235 Munich, CEO: Wolfgang Denk
> Office:  Kirchenstr. 5,       D-82194 Groebenzell,            Germany
> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
> The amount of time between slipping on the peel and  landing  on  the
> pavement is precisely 1 bananosecond.

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