[Avila] Gateworks and the Intel NPEs

Tue Jan 16 13:59:50 EST 2007

After digging through the modules/ixp425/net-2.0 code
the many interrupts for ethernet port seems to be
intentional as indicated by this comment in
ixp400_eth.c:

/*
 * TIMERS
 *
 * PMU Timer : This timer based on IRQ  will call the
qmgr dispatcher 
 * function a few thousand times per second.
 *
 * Maintenance Timer : This timer run the maintanance
action every 
 * 60 seconds approximatively.
 *
 */

Oh well . . .

--- devel <devel at oberonwireless.com> wrote:

> Tim,
> 
>     I don't have anything really formal to show the
> list as far as what is 
> happening when a wifi client loses connection (or
> appears to). We are using 
> madwifi, bridging, and hostapd. This occurs with no
> encryption as well as 
> over the bridge (ath0 & eth0 is promiscuous) so
> hostapd wouldn't be running 
> at that point of course. What I have seen using
> ethereal is, the client 
> can't get receive traffic back across the AP.
> Ethereal sees the request AND 
> the reply for a ping on a wired PC on the other side
> of the AP, but this 
> never gets back to the client. I put tcpdump on the
> AP and it never sees the 
> reply from the wired PC.
> 
>     Currently, I have gone back and stripped out any
> work I've done in the 
> NPE driver (which really wasn't much) and I do have
> this monitored as I let 
> this AP run with a console to a PC. So for over a
> week now, no problems. But 
> I will let this go awhile yet before I say things
> seem relsolved. And yes I 
> am using the npe_learing=0.
> 
> Dave....I too would like to know when the next
> release of the BSP would be. 
> We are seeing the interrupt problem that many on the
> list have noted. Also 
> I've heard madwifi bark about the improvements to
> the kernel build in the 
> 2.6.16+ kernels and they seem to like it.
> 
> Thanks guys.
> 
> Travis
> 
> 
> ----- Original Message ----- 
> From: "Tim Harvey" <tim_harvey at yahoo.com>
> To: "Avila" <avila at lists.unixstudios.net>
> Sent: Sunday, January 07, 2007 1:35 PM
> Subject: Re: [Avila] Gateworks and the Intel NPEs
> 
> 
> >I would have to agree with Dave here as to where
> the problem is.  I have 
> >been using the IAL (with npe_learning=0) for quite
> some time and I've never 
> >run into this problem (at least that I know of). 
> Travis, do you have a 
> >simple test case that shows this problem?  What
> other components are you 
> >using in your setup (madwifi/hostap/bridge?).
> >
> > Dave, any target date for your next BSP?
> >
> > I've been working on updating my kernel, however I
> use snapgear for 
> > userland with glibc.  I've found that the
> glibc-2.25 that snapgear uses is 
> > very outdated and has issues building with newer
> toolchains which are 
> > required to build the latest kernels.  Therefore,
> if your using 
> > snapgear+glibc+linux-2.6.18+ you have to use a
> different toolchain for 
> > building the kernel as you do for snapgear
> userland (glibc specifically). 
> > I'm not sure how easy it is to update glibc in
> snapgear (I notice that 
> > snapgear 3.4.0 does not even include glibc).
> >
> > So, what are you people using with your newer
> kernels with regards to 
> > userland?  buildroot?
> >
> > Thanks,
> >
> > Tim
> >
> > ----- Original Message ----
> > From: Dave G <daveg at unixstudios.net>
> > To: Avila <avila at lists.unixstudios.net>
> > Sent: Friday, January 5, 2007 12:00:00 PM
> > Subject: Re: [Avila] Gateworks and the Intel NPEs
> >
> > Hi Travis/List,
> >
> >
> > I can comment on the roadmap question. Our plans
> are to include latest IAL
> > as well as the GPL driver in our next BSP release
> so you can choose either
> > to use.
> > We currently don't have plans to dig into the IAL
> code to do repair work,
> > however if the next IAL release exhibits the same
> issues previous releases
> > have we likely would dig into it to see what we
> can find. As you all know
> > the IAL code is developed and provided by Intel
> and not by Gateworks.
> >
> >
> > My own thoughts on the reported IAL/NPE issues are
> probably not shared by
> > most. Because it seems that the reported IAL
> issues persist over different
> > versions of the IAL and also since Intel has
> failed to acknowledge and/or
> > repair the reported issues, I suspect that there
> may not be any issues
> > whatsoever in the IAL or if there are they may be
> very minor. I find it 
> > hard
> > to believe that Intel would continue to release
> IAL versions which exhibit
> > the same reported issues without Intel doing
> anything about it if such
> > issues indeed existed and were validated by Intel.
> I realize that many of
> > the IAL releases are just feature/cpu upgrades and
> not always fixes.
> >
> > IMHO I think that the reported issues could very
> well be related to the
> > environment or manner in which many of us use the
> NPEs.
> >
> > For example, the npe_learning=0 argument passed to
> the ixp400_eth module
> > turns off MAC learning in the IAL/driver. This
> argument MUST be used if 
> > the
> > NPE is to be a part of a bridge where MAC learning
> is already being done
> > (Linux ethernet bridging). Without turning off
> npe_learning in the IAL 
> > some
> > funky things happen.
> > Looking at the various available microcode (the
> microcode loaded into the
> > NPE) and the different features that each of them
> employ causes me to
> > suspect that I might have a problem down the road
> because the IAL is doing
> > something like:
> >
> >
> NPEA_ETH_SPAN_MASK_FIREWALL_VLAN_QOS_HDR_CONV_EXTMIB
> > NPEA_ETH_SPAN_VLAN_QOS_HDR_CONV_EXTMIB
> >
>
NPEA_ETH_LEARN_FILTER_SPAN_MASK_FIREWALL_VLAN_QOS_EXTMIB
> > NPEB_ETH_LEARN_FILTER_SPAN_FIREWALL_VLAN_QOS
> > NPEB_ETH_SPAN_FIREWALL_VLAN_QOS_HDR_CONV
> >
> > yet I am planning on doing some of the same in the
> kernel via iprout2,
> > iptables, etc, etc.
> >
> > I haven't looked deeply into even if the above
> features are actually being
> > performed in the NPE or how to control them,
> except that I know using
> > npe_learning=0 absolutely cleans up the bridging
> issues I was experiencing
> > when ixp0/ixp1 was part of a bridge group.
> Additionally I haven't looked
> > specifically at the ramifications of the NPE
> microcode doing something 
> > like
> > HDR_CONV while I am doing iptables -t mangle
> stuff.
> >
> > Anyway, if we end up experiencing IAL/NPE issues
> after this next BSP 
> > release
> > I would suspect that we would begin looking in the
> above described areas.
> >
> >
> > Thanks!
> >
> >
> > -Dave G
> >
> >
> >
> >
> >
> >
> >
> > Hey list,
> >
> >    I am just wondering where Gateworks stands with
> the 
=== message truncated ===

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