[Asterisk-Users] Sound quality issue in one direction and wctdm problem with APIC enabled kernel

[Chris Miller]

I'm chasing down a pop/click type of disturbance on a PBX system.
Strangely, the disturbance is only heard by the outside caller, the
internal recipient hears the caller crystal clear. This seems to have
crept up when upgrading the zaptel driver to the 1.2 series while
running 1.0.10. I went ahead and upgraded the entire system to 1.2.4.

The system is a ~2Ghz AMD 32bit system, with 512MB of memory and nothing
other than Asterisk running. Phone traffic is minimal, perhaps 3
simultaneous calls max, but the problem occurs with just one call. It's
located in a data center with ~20ms pings to the ITSP and ~20ms pings to
the remote office IP phones.

Up to this point, ztdummy was in use without problems, although the
timing (zttest) was a hair under the recommended threshold. I dropped in
a TDM400P for testing, and although the timing improved, the symptom
remained. The system has an IDE drive, and I verified the hdparm dma/irq
settings were enabled. The TDM card was sharing interrupts, so I
recompiled the kernel with APIC support. Unfortunately the wctdm module
will no longer load after recompile and install into the new kernel
directory. I went back to the ztdummy driver with the same problem.
Below is the relevant errors and info.

Chris

# modprobe wctdm
FATAL: Error inserting wctdm (/lib/modules/2.6.12-prep/misc/wctdm.ko):
Unknown symbol in module, or unknown parameter (see dmesg)
FATAL: Error running install command for wctdm

# dmesg
wctdm: disagrees about version of symbol zt_receive
wctdm: Unknown symbol zt_receive
wctdm: disagrees about version of symbol zt_qevent_lock
wctdm: Unknown symbol zt_qevent_lock
wctdm: disagrees about version of symbol zt_ec_chunk
wctdm: Unknown symbol zt_ec_chunk
wctdm: disagrees about version of symbol zt_transmit
wctdm: Unknown symbol zt_transmit
wctdm: disagrees about version of symbol zt_unregister
wctdm: Unknown symbol zt_unregister
wctdm: disagrees about version of symbol zt_hooksig
wctdm: Unknown symbol zt_hooksig
wctdm: disagrees about version of symbol zt_register
wctdm: Unknown symbol zt_register

# cat /proc/interrupts
            CPU0
   0:   34991774    IO-APIC-edge  timer
   1:         10    IO-APIC-edge  i8042
   8:          1    IO-APIC-edge  rtc
   9:          1   IO-APIC-level  acpi
  12:        111    IO-APIC-edge  i8042
  14:     170392    IO-APIC-edge  ide0
  15:     383872    IO-APIC-edge  ide1
  18:          0   IO-APIC-level  SiS SI7012, SiS SI7013 Modem
  19:     164220   IO-APIC-level  eth0
  20:          0   IO-APIC-level  ohci_hcd:usb2
  21:          0   IO-APIC-level  ohci_hcd:usb3
  22:          0   IO-APIC-level  ohci_hcd:usb4
  23:          0   IO-APIC-level  ehci_hcd:usb1
NMI:          0
LOC:   34991738
ERR:          0
MIS:          0