problems tuning pci latency for linux audio

andy baxter andy at
Thu Jul 24 20:48:41 UTC 2008


I am trying to get the jackd audio daemon to work without xruns on my 
system (a thinkpad X61s). At the moment it is not working at all because 
there are too many xruns (more than one a second). I was following the 
advice on a web page which said to use setpci to change the interrupt 
priority like this:

setpci -v -s 00:1b.0 latency_timer=ff

lspci shows:

00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio 
Controller (rev 03)
        Subsystem: Lenovo ThinkPad T61
        Flags: bus master, fast devsel, latency 0, IRQ 19
        Memory at f8220000 (64-bit, non-prefetchable) [size=16K]
        Capabilities: [50] Power Management version 2
        Capabilities: [60] Message Signalled Interrupts: Mask- 64bit+ 
Queue=0/0 Enable-
        Capabilities: [70] Express Unknown type IRQ 0

However, the listing from lspci doesn't change after running setpci. Am 
I doing something wrong, and is this the right way to improve audio 
performance anyway?

Also, there is an option in the BIOS settings to change the IRQ used by 
various devices; is this worth looking at?

any help appreciated.


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