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

[Mark Knecht]

On 11/10/05, Nathan <thegnu at gmail.com> 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 at lightning ~ $ 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 at lightning ~ $

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 at lightning ~ $ 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 at lightning ~ $

My interrupts are considerably different:

mark at lightning ~ $ 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 at lightning ~ $

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

mark at lightning ~ $ 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 at lightning ~ $

I hope this helps.

cheers,
Mark