[asterisk-users] TE410P (1st) without cables always green

[Shaun Ruffell]

On Thu, Feb 09, 2012 at 02:11:12PM -0200, Marcio Gomes wrote:
> Hello Shaun,
> 
> 1) dahdi-linux-complete-2.2.0.2+2.2.0 , is generatiing 1K int/s
> after patches..
> 
> 2) Looking in 2.2.1 code, i see to wct4xxp.c the alarmdebounce set
> in 2500 and in 2.2.0 the alarmdebounce seted to 0,
> 
> I load the module with alarmdebouce=0 paramter => the interrupts are
> up to 1000 int/s
> 
> After this, I test all versions until dahdi-linux-complete-2.6.0+2.6.0
> 
> cd version
> make distclean
> make
> make install
> /etc/init.d/dahdi stop ;sleep 3; modprobe dahdi;  modprobe wct4xxp
> debug=1 alarmdebounce=0  ; dahdi_cfg
> .itop =>  to see interrupts.
> 
> always are 1000 ints/s
> 
> I not touch in  losalarmdebounce=0 aisalarmdebounce=0
> yelalarmdebounce=0 module paramters.
> 
> 
> 3) Can you explain-me aboute how the alarmdebounce and its variants
> ( LOS, YEL, etcc ) impacts the system perfomance and how
> can i fine tune this ?

Marcio,

My understanding is that (and I don't have the spec in front of me)
is that AT&T 54016 defines a standard for how long a red alarm
condition should be on the span before the framer sends yellow alarm
to the remote side. Those changes for alarm debounce were put in to
comply with that standard.

It does surprise me to learn that on Gen1 cards, setting the
alarmdebounce module parameter to 0 allows those boards to function
normally. After looking through the differences between 2.2.0.2 and
2.2.1 the only change that looks related at the hardware level in
that case is whether the framer is commanded to send yellow alarm or
not when in alarm. When alarmdebounce is 0, the framer will start
sending yellow right after the first interrupts where red alarm is
detected. Perhaps the gen1 cards stop interrupting the host when in
alarm, so the driver debounce never trips, never starts sending
yellow, which *may* be what causes the interrupts to keep flowing
in?

Just thinking out loud here but I'm guessing it may be fair to just
set alarmdebounce to 0 by default on gen1 cards.

With dahdi-linux 2.2.0.2 does your card function if you set alarm
debounce to 2500?

-- 
Shaun Ruffell
Digium, Inc. | Linux Kernel Developer
445 Jan Davis Drive NW - Huntsville, AL 35806 - USA
Check us out at: www.digium.com & www.asterisk.org