Re: [linux-audio-user] APIC, IRQ, and an HDSP9652

From: Mark Knecht <markknecht@email-addr-hidden>
Date: Thu Nov 10 2005 - 19:03:47 EET

On 11/10/05, Nathan <thegnu@email-addr-hidden> wrote:
> Hi all,
> This is my first post here, so hello everybody. I'm running
> PlanetCCRMA's FC3 distro (low-latency kernel
> 2.6.11-0.3.rdt.rhfc3.ccrma) on an Athlon 64 3000+ w. an NF4 chipset.
> As far as sound goes, I'm using the integrated CK804 (w. snd-intel8x0
> drivers) and an RME HDSP9652 (w. snd-hdsp).
>
> The questions:
> 1. I've read a lot about getting the IRQ of the soundcard to as high a
> priority as possible. How important is this? Is it possible with
> setpci if I reserve an IRQ in the BIOS, or only by swapping cards?
> 2. Should I enable or disable APIC? I've heard muddy answers, but
> what I know is that it always leaves my HDSP9652 at IRQ's from 16-20.
> Here's the output of cat /proc/interrupts.
> # cat /proc/interrupts
> CPU0
> 0: 1556590 XT-PIC timer 0/56590
> 1: 3324 XT-PIC i8042 0/3324
> 2: 0 XT-PIC cascade 0/0
> 3: 3948 XT-PIC NVidia CK804 0/3948
> 4: 0 XT-PIC hdsp 0/0
> 5: 97413 XT-PIC ohci_hcd, nvidia 0/97413
> 7: 0 XT-PIC parport0 0/0
> 8: 1 XT-PIC rtc 0/1
> 9: 0 XT-PIC acpi 0/0
> 10: 0 XT-PIC libata, ehci_hcd 0/0
> 11: 37516 XT-PIC libata, eth0 0/37516
> 12: 146561 XT-PIC i8042 0/46561
> 14: 15416 XT-PIC ide0 0/15416
> 15: 12105 XT-PIC ide1 0/12105
> NMI: 0
> LOC: 1556573
> ERR: 0
> MIS: 0
>
> 3. Would you recommend I set my first soundcard to be the CK804 or
> should I leave the RME as the first soundcard?
> 4. Should I just disable the CK804 and throw in an emu10k1? Becuase I
> could do that, too.
>
> Any help would be appreciated, and if I left something out, let me
> know. Thanks!
> -Nathan
>
>
Hi Nathan,
   It sounds like we have almost identical hardware. I've got an
NForce4 motherboard (A8N-E) and an AMD64 3000+ also. I have both sound
cards working fine. Here's my Alsa config stuff:

mark@email-addr-hidden ~ $ cat /etc/modules.d/alsa
# Alsa 0.9.X kernel modules' configuration file.
# $Header: /var/cvsroot/gentoo-x86/media-sound/alsa-utils/files/alsa-modules.con
f-rc,v 1.4 2004/11/16 01:31:22 eradicator Exp $

# ALSA portion
alias char-major-116 snd
# OSS/Free portion
alias char-major-14 soundcore

##
## IMPORTANT:
## You need to customise this section for your specific sound card(s)
## and then run `update-modules' command.
## Read alsa-driver's INSTALL file in /usr/share/doc for more info.
##
## ALSA portion
alias snd-card-0 snd-intel8x0
options snd-intel8x0 index=0
alias snd-card-1 snd-hdsp
options snd-hdsp index=1
## OSS/Free portion
alias sound-slot-0 snd-card-0
## alias sound-slot-1 snd-card-1
##

# OSS/Free portion - card #1
alias sound-service-0-0 snd-mixer-oss
alias sound-service-0-1 snd-seq-oss
alias sound-service-0-3 snd-pcm-oss
alias sound-service-0-8 snd-seq-oss
alias sound-service-0-12 snd-pcm-oss
## OSS/Free portion - card #2
## alias sound-service-1-0 snd-mixer-oss
## alias sound-service-1-3 snd-pcm-oss
## alias sound-service-1-12 snd-pcm-oss

alias /dev/mixer snd-mixer-oss
alias /dev/dsp snd-pcm-oss
alias /dev/midi snd-seq-oss

# Set this to the correct number of cards.
options snd cards_limit=2
mark@email-addr-hidden ~ $

This sets up the NVidia chip as the default sound device and the HDSP
9652 as secondary. I find this better for web browsing, etc.

mark@email-addr-hidden ~ $ cat /proc/asound/cards
0 [CK804 ]: NFORCE - NVidia CK804
                     NVidia CK804 with ALC850 at 0xda103000, irq 225
1 [DSP ]: H-DSP - Hammerfall DSP
                     RME Hammerfall HDSP 9652 at 0xda000000, irq 58
mark@email-addr-hidden ~ $

My interrupts are considerably different:

mark@email-addr-hidden ~ $ cat /proc/interrupts
           CPU0
  0: 7802062 IO-APIC-edge timer
  1: 1099 IO-APIC-edge i8042
  7: 2 IO-APIC-edge lpptest
  8: 100746 IO-APIC-edge rtc
  9: 0 IO-APIC-level acpi
 12: 47669 IO-APIC-edge i8042
 14: 48 IO-APIC-edge ide0
 50: 2 IO-APIC-level ehci_hcd:usb1
 58: 0 IO-APIC-level hdsp
 66: 2 IO-APIC-level ohci1394
217: 875032 IO-APIC-level ohci_hcd:usb2, eth0
225: 4615 IO-APIC-level libata, NVidia CK804
233: 71628 IO-APIC-level libata
NMI: 218
LOC: 7801003
ERR: 1
MIS: 0
mark@email-addr-hidden ~ $

Most likely this is due to my using a very new kernel:

mark@email-addr-hidden ~ $ uname -a
Linux lightning 2.6.14-rt9 #1 PREEMPT Wed Nov 9 08:47:47 PST 2005
x86_64 AMD Athlon(tm) 64 Processor 3000+ AuthenticAMD GNU/Linux
mark@email-addr-hidden ~ $

I hope this helps.

cheers,
Mark
Received on Thu Nov 10 20:15:10 2005

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