ALSA sound and pnp [was Re: /dev/dsp not found: KDE/ALSA - pls help!]
Stephan, thanks for your efforts. I have some more info that may narrow
down the problem (namely no sound with KDE/ALSA 0.9/kernel 2.4.16), which I
think centers on pnp. The card, a Soundblaster AWE 64 is ISAPNP. I
actually haven't been able to get sound out of it for anything for awhile.
I found that if I used modprobe to remove the driver and then reinstall, I
had sound as long as I turned the mixer up. Note that the mixer didn't
help before (because sound was not detected).
Before I did the modprobe cat /proc/isapnp showed the sound card was not
active. Originally I thought this meant it hadn't been turned on, but I
think it means that commands directed to /proc/isapnp would not effect this
device (unless they changed the active device). True?
After the remove/load sequence /proc/isapnp showed the card was
active. This also disconnected my modem.
My 2.4.16 is compiled with isapnp support; so is the alsa driver; and I
have enabled it in the alsa load options. Those options also specify IRQ
etc for the soundcard. Those specifications are the same as those shown
from /proc/isapnp before the load/unload.
I think I now understand that the alsa pnp options mean that alsa will use
pnp to *set* the card parameters. Only setting seems consistent with
disabling the modem. I was assuming it was using it to *read* the
values. Is the setting interpretation correct? Why doesn't it just read
the parameters, which seems much saner?
To get this to work properly it seems I need to tell the kernel what
resources to use for the card, but the kernel pnp options only seem to
exclude resources from assignment to any card. And telling it where to
assign resources seems a step back to the old isapnp tools.
So there are 2 issues:
DIAGNOSIS. None of this quite explains what's going wrong. Here's a
theory: the alsa driver sets the resources of the card, and then something
else does some more pnp stuff that knocks it out.
CURE: How do I get it to work? Obviously I would prefer to have the alsa
driver figure out what resources the card is using, but at this point I'll
take anything that works.