[asterisk-users] tdm loosing interrupts and latency

[Lyle Giese]

Alex Samad wrote:
> Hi
>
> I have come across a problem, with my tdp410 and soekris board
> (basically pc on a chip amd geode cpu).
>
> I am using the box as a firewall/asterisk box. The problem occurs when I
> drop ppp and I get dead loop dectiotn going, I seem to lose interrupts
> and get lots of messages in syslog from wctdm24xx saying missed
> interrupt increasing latency
>
> its out lined here
> (http://forums.digium.com/viewtopic.php?p=126997&highlight=&sid=9de59f41f1a93ee8701b28fdd0cf6073)
>
> Seems like the driver (and this is in zaptel & dadhi code), increases
> latency by +1 until 30. and then the card seems to not work. In my case
> I have seen latency increase from 8m (I have this as a starting point in
> the module load) up to 17ms usually around here the fxs and fxo ports
> stop working ..... I have to unload and then reload the module. bummer.
>
>
> I can think of a couple of solutions 
>
> 1) build some intelligence to bring down the number when things are okay
> 2) build logic to say if a number is provided on module load to fix it
> to that
> 3) add a sysfs (/proc) interface to allow changing this value on the fly
>
> I could also try and solve my problem with the dead loop detection
>
>  cat /proc/interrupts 
>            CPU0       
>   0:   23809265    XT-PIC-XT        timer
>   1:          0    XT-PIC-XT        i8042
>   2:          0    XT-PIC-XT        cascade
>   4:        255    XT-PIC-XT        serial
>   5:     459544    XT-PIC-XT        eth1
>   8:          0    XT-PIC-XT        rtc0
>  10:   95177163    XT-PIC-XT        wctdm24xxp0
>  11:   28938443    XT-PIC-XT        eth0
>  12:   28938632    XT-PIC-XT        eth3
>  14:    3624228    XT-PIC-XT        ide0
>  15:          1    XT-PIC-XT        ehci_hcd:usb1, ohci_hcd:usb2
> NMI:          0   Non-maskable interrupts
> LOC:          0   Local timer interrupts
> TRM:          0   Thermal event interrupts
> SPU:          0   Spurious interrupts
> ERR:          0
> MIS:          0
>
>
> as you can see with the interrupts the wctdm24xxp0 is above eth0 (local
> lan) and eth3 (my adsl)
>
> eth1 is wireless and not heavily used
>
>
> So any one had this problems, any other possible solution to this ?
>
>
> How to engage digium to providing a fix for this ?
>
> Alex
>
>   
If your ppp is dropping, that means you have lost Internet connectivity,
correct?  If that is the case, then that is your problem as Asterisk
does not tolerate the lose of DNS resolution very well.

Lyle Giese
LCR Computer Services, Inc.