Conflict between CPU Frequency scaling and snd_intel8x0m ?

From: Leszek Koltunski
Date: Fri Nov 25 2005 - 01:36:06 EST



kernel: vanilla 2.6.14 , not tainted
OS: Debian Etch, udev 073
Thinkpad R51

*************************************************************************
The problem: after compiling in CPU_FREQ, sound stops working: xmms complains about

Failed to open audio device (/dev/dsp) No such device

'dsp' is indeed missing in /dev.

After a 'mknod -m 660 dsp c 14 0' it does not complain any more, but even though xmms appears to be playing, no actual sound can be heard.
*************************************************************************

Now, here's .config of a kernel which has sound working:
http://www.3miasto.net/~leszek/config-2.6.14-sound-working

In this one, sound does not work:
http://www.3miasto.net/~leszek/config-2.6.14-sound-not-working

The only difference between the two

utumno:/home/leszek/tmp# diff config-2.6.14-sound-working config-2.6.14-sound-not-working
4c4
< # Wed Nov 9 20:45:34 2005
---
# Fri Nov 25 12:35:25 2005
200c200,232
< # CONFIG_CPU_FREQ is not set
---
CONFIG_CPU_FREQ=y
CONFIG_CPU_FREQ_TABLE=y
# CONFIG_CPU_FREQ_DEBUG is not set
CONFIG_CPU_FREQ_STAT=y
# CONFIG_CPU_FREQ_STAT_DETAILS is not set
CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE=y
# CONFIG_CPU_FREQ_DEFAULT_GOV_USERSPACE is not set
CONFIG_CPU_FREQ_GOV_PERFORMANCE=y
CONFIG_CPU_FREQ_GOV_POWERSAVE=y
CONFIG_CPU_FREQ_GOV_USERSPACE=y
# CONFIG_CPU_FREQ_GOV_ONDEMAND is not set
CONFIG_CPU_FREQ_GOV_CONSERVATIVE=y

#
# CPUFreq processor drivers
#
# CONFIG_X86_ACPI_CPUFREQ is not set
# CONFIG_X86_POWERNOW_K6 is not set
# CONFIG_X86_POWERNOW_K7 is not set
# CONFIG_X86_POWERNOW_K8 is not set
# CONFIG_X86_GX_SUSPMOD is not set
# CONFIG_X86_SPEEDSTEP_CENTRINO is not set
# CONFIG_X86_SPEEDSTEP_ICH is not set
# CONFIG_X86_SPEEDSTEP_SMI is not set
# CONFIG_X86_P4_CLOCKMOD is not set
# CONFIG_X86_CPUFREQ_NFORCE2 is not set
# CONFIG_X86_LONGRUN is not set
# CONFIG_X86_LONGHAUL is not set

#
# shared options
#
# CONFIG_X86_SPEEDSTEP_LIB is not set

is the CPU_FREQ option.

*******************************************************************
utumno:/home/leszek/tmp# lsmod
Module Size Used by
kqemu 39112 0
radeon 103232 1
drm 62740 2 radeon
lirc_sir 15360 0
lirc_dev 12644 1 lirc_sir
ipt_MASQUERADE 3008 1
iptable_nat 7364 1
ip_nat 16052 2 ipt_MASQUERADE,iptable_nat
ip_conntrack 44048 3 ipt_MASQUERADE,iptable_nat,ip_nat
ip_tables 21824 2 ipt_MASQUERADE,iptable_nat
nls_iso8859_1 3776 1
nls_cp437 5440 1
ibm_acpi 24768 0
tun 8320 0
snd_intel8x0m 14404 0
snd_intel8x0 28256 0
snd_ac97_codec 86140 2 snd_intel8x0m,snd_intel8x0
snd_ac97_bus 1792 1 snd_ac97_codec
8139too 23360 0
mii 4224 1 8139too
snd_pcm 78280 3 snd_intel8x0m,snd_intel8x0,snd_ac97_codec
snd_timer 20228 1 snd_pcm
snd 44132 5 snd_intel8x0m,snd_intel8x0,snd_ac97_codec,snd_pcm,snd_timer
snd_page_alloc 8136 3 snd_intel8x0m,snd_intel8x0,snd_pcm
ehci_hcd 30152 0
uhci_hcd 30032 0
ipw2200 120808 0
i810_audio 33172 0
ac97_codec 16844 1 i810_audio
usbcore 105984 3 ehci_hcd,uhci_hcd
intel_agp 18780 1
agpgart 28232 2 drm,intel_agp
serial_core 17728 0
yenta_socket 22732 3
rsrc_nonstatic 11200 1 yenta_socket
ieee80211 19912 1 ipw2200
ieee80211_crypt 4228 1 ieee80211
soundcore 7392 2 snd,i810_audio

****************************************************************************

I fail to see what CPU_FREQ would have to do with a working sound, so I presume it might be a bug...

Leszek
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