Re: [linux-audio-user] latency questions

D R Holsbeck is on permanent record as saying: :On Tue, 2002-10-15 at 17:48, G. M. Bodnar wrote: :> First off, I'll mention that I'm using a Dell Inspiron 2650 laptop. :> I'm running debian unstable with 2.4.19. : :I a,m running the same setup on an IBM A31 Thinkpad, and do not have :problems with latencies. Even while running 24chs in Ardour, using a an :RME H-DSP interface. So I would venture that your problem has more to do :with Dell than Linux. I'm pretty certain of this actually. This is the first problem I've had with linux+alsa in quite some time. :> 1) DMA transer won't enable. I've enabled DMA transfers in the kernel :> as suggested by the howto. However, I'm unable to turn on dma access :> with hdparm. I'm told the operation is not permitted. : :More evidence that it is a hardware issue. Or hardeware/software :incompatibiliy to be more politicly correct. After a lot more poking around, it seems as if this is fixed in a prerelease for 2.4.20. I'll have to sneaker-net some patches home with me tonight. :> 2) IRQ mess. dmesg lists that almost every device that is detected is :> on irq 10, including the onboard sound (i8x0) and video card (nVidia). :> As a result, in X, I get static and pops as the audio is delayed. :> Searching further, I noticed a message saying the APIC wasn't being used :> due to a buggy bios provided by Dell. This could explain why everything :> is pushed to IRQ 10. : :All my devices end up on 11, but APIC takes care of things nicely. I'll have to do some more testing around this, then. Maybe buffering would clean things up a bit. --- -