asterisk users - May 2011 - Multiple cards using same IRQ - getting IRQ errors and hissing

I am running Asterisk 1.16.2.13, dahdi 2.4.0 and libpri 1.4.11.4 on an
HP ML110 G6 using Ubuntu Linux 10.04 LTS.

I have two Digium TE121 single T1 port cards and a Digium AEX800
8-port FXS card.  All PCI Express cards.

Co-workers are hearing hissing sounds on some calls, and I am getting
IRQ errors when running "dahdi show status".

I see that sharing IRQs for Digium cards isn't recommended, so I'm
trying to set it so each card gets its own.  From the few web sites
I've read so far, including Digium's FAQ site, I've added ACPI and
verified that the BIOS does not give me the ability to manually set
the IRQ.  I've even taken one of the TE121's out of the server (it
isn't being used anyways).  Everything I've done so far has not fixed
it.  All the cards (as well as USB1) all use IRQ 16.

The other option given was to use setpci, but I am unfamiliar with
that command.  I did what I could to try and find the setting (based
on what the man page on Ubuntu's web site) where I could see the value
16, but not getting anywhere.

I know that this is more of an Asterisk forum than Digium.  If I need
to put in a case at Digium I will, but wanted to see if there were any
suggestions here before I pursued that.

Any help would be appreciated.

Dean Hoover

On Tue, May 03, 2011 at 09:32:06AM -0500, Dean Hoover
wrote:
> I am running Asterisk 1.16.2.13, dahdi 2.4.0 and libpri 1.4.11.4 on an
> HP ML110 G6 using Ubuntu Linux 10.04 LTS.
> 
> I have two Digium TE121 single T1 port cards and a Digium AEX800
> 8-port FXS card.  All PCI Express cards.
> 
> Co-workers are hearing hissing sounds on some calls, and I am getting
> IRQ errors when running "dahdi show status".
> 
> I see that sharing IRQs for Digium cards isn't recommended, so I'm
> trying to set it so each card gets its own.  From the few web sites
> I've read so far, including Digium's FAQ site, I've added ACPI
and
> verified that the BIOS does not give me the ability to manually set
> the IRQ.  I've even taken one of the TE121's out of the server (it
> isn't being used anyways).  Everything I've done so far has not
fixed
> it.  All the cards (as well as USB1) all use IRQ 16.
With the TE121 and AEX800, sharing interrupts really isn't a problem
anymore.  The 'voicebus' cards, which the TE122 and AEX800 are, will in
most cases be able to accomodate most IRQ sharing situations.
> The other option given was to use setpci, but I am unfamiliar with
> that command.  I did what I could to try and find the setting (based
> on what the man page on Ubuntu's web site) where I could see the value
> 16, but not getting anywhere.
> 
> I know that this is more of an Asterisk forum than Digium.  If I need
> to put in a case at Digium I will, but wanted to see if there were any
> suggestions here before I pursued that.
> 
> Any help would be appreciated.
I would recommend updating to dahdi-linux version 2.4.1.2.  Commit r9687
[1] on the 2.4 branch addresses something similar to what you have
reported.

[1] http://svn.asterisk.org/view/dahdi?view=revision&revision=9687

I would also *highly* recommend ensuring that your BIOS on your
motherboard is the latest. There have been several cases recently where
the PCI Express root complex was misconfigured by BIOS which resulted in
corrupted data transfers.

Cheers,
Shaun

---
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

On 2011-05-03 16:32, Dean Hoover wrote:
> I am running Asterisk 1.16.2.13, dahdi 2.4.0 and libpri 1.4.11.4 on an
> HP ML110 G6 using Ubuntu Linux 10.04 LTS.
>
> I have two Digium TE121 single T1 port cards and a Digium AEX800
> 8-port FXS card.  All PCI Express cards.
>
> Co-workers are hearing hissing sounds on some calls, and I am getting
> IRQ errors when running "dahdi show status".
>
> I see that sharing IRQs for Digium cards isn't recommended, so I'm
> trying to set it so each card gets its own.  From the few web sites
> I've read so far, including Digium's FAQ site, I've added ACPI
and
> verified that the BIOS does not give me the ability to manually set
> the IRQ.  I've even taken one of the TE121's out of the server (it
> isn't being used anyways).  Everything I've done so far has not
fixed
> it.  All the cards (as well as USB1) all use IRQ 16.
>
> The other option given was to use setpci, but I am unfamiliar with
> that command.  I did what I could to try and find the setting (based
> on what the man page on Ubuntu's web site) where I could see the value
> 16, but not getting anywhere.
>
> I know that this is more of an Asterisk forum than Digium.  If I need
> to put in a case at Digium I will, but wanted to see if there were any
> suggestions here before I pursued that.
>
> Any help would be appreciated.
>
> Dean Hoover
>
A month ago I had similar problems with a HP DL360g6 and a HP DL380g7 
running Debian 5 "Lenny".
In the HP DL360g6 I had one TE121. I noticed IRQ misses and the problem 
was easily reproduced
by running dahdi_maint to enable loopback and patlooptest while 
compiling asterisk to create some i/o.

When I installed Debian 6 "Squeeze" instead the problem went away. 
Tested with both servers above.
On this page I found some information about APIC (Advanced Programmable 
Interupt Controller)
http://www.asteriskguru.com/tutorials/pci_irq_apic_tdm_ticks_te410p_te405p_noise.html
(quite old but informative)

I haven't got the time to verify the root cause of the problem yet (I've
planned to do this at the end of this month)
but my theory is that it has something to do with the kernels APIC 
handling that was fixed between Debian 5 and 6.

Maybe you experience something similar?

/Johan

-- 
Johan Wilfer                 email: johan at jttech.se
JT Tech | Utvecklare         webb: http://jttech.se
direkt: +46 31 380 91 01  support: +46 31 380 91 00