[linux-audio-user] soundcard sharing irq with idle devices

Lee Revell rlrevell at joe-job.com
Fri Dec 1 15:05:56 EST 2006

On Fri, 2006-12-01 at 11:39 -0800, st wrote:
> I found this.  It looks like it might be
> of interest to you.
> http://cae.best.vwh.net/irqtune/

Useless with -rt kernel which already lets you prioritize interrupts by
setting the RT priority of the handler.

IRQ sharing is hard wired in a laptop - it's not going to be possible
for you to get the soundcard on its own IRQ.  It will help if you don't
load drivers for other devices sharing that IRQ though.

Anyway having your soundcard on a non-shared IRQ is overrated - as long
as you aren't sharing it with a "heavy" device like a disk controller or
ethernet adapter.  If you find it impossible to eliminate xruns on a
laptop there's a good chance that SMI is the problem and you must use a
higher latency.


> Atte André Jensen wrote:
> > Hi
> > 
> > Reading the thread(s) on realtime-kernels, I decided to have another go
> > at putting my sound card (IBM T41 laptop) on it's own IRQ. Through luck,
> > some black BIOS-magic and help from linux thinkpad mailing list I
> > managed to move the sound card, PC-card, modem and SMBus
> > controller(whatever that is) to their own IRQ. I'm still trying to get
> > *only* the sound card's IRQ moved.
> > 
> > My question is: Since I don't use the pc-card or the modem, and provided
> > that SMBus is something I don't use, will having these extra stuff on
> > the same IRQ as the sound card be a problem? Will it make any difference
> > if I don't load the kernel modules for the pc card/modem thereby
> > disabling them?
> > 

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