5 Apr
2007
5 Apr
'07
10:17 a.m.
On Thu, 2007-04-05 at 02:00 -0400, Spencer Russell wrote:
Recently I posted regarding nice low latencies on my
brand-spankin-new
Thinkpad R60. I was a bit premature though, because when I actually
run any sound through jack I'm still getting lots of pops and clicks
in my audio. I am not, however, getting any Xruns. I'm not sure what
to look for as a culprit.
I already enabled "force 16 bit", which got rid of some nasty
distortion, maybe something wacky with my IRQs? One of my worries is
that the HDA card is on the same interrupt as my firewire and one of
my USB drives. When I remove the modules though, leaving only HDA on
its own interrupt, i still get the pops.
When I use audio without jack I get no clicks or pops, and changing
jackd to capture only doesn't seem to help. I also boosted the
priority of that interrupt thread with chrt --fifo --pid 99 `pidof
'IRQ 4'` without any change.
What could cause clicks without xruns? I'm baffled.
PCI bus hogging, for one thing. consider running a script like this
during system startup (mine is in /etc/rc.d/init.d/pcilatency). yours
would need adjusting to reflect the PCI IDs of the actual interfaces you
have installed.
#!/bin/sh
case $1 in
start)
# "open up" the PCI bus by allowing fairly long bursts for
all devices, increasing performance
setpci -v -s "*:*.*" latency_timer=b0
# maximise latency for RME Hammerfall, thus allowing
# more data per PCI transfer and minimizing xfuns
setpci -v -s 01:04.0 latency_timer=ff
# ditto for the onboard AC97 audio interface
setpci -v -s 00:07.5 latency_timer=ff
esac
exit 0