First experiences with Linux kernel 2.6.32

Last week Linux 2.6.32 was released. I’m currently using it with the bfs-scheduler patchset.

I experienced three glitches so far on my Gentoo installation. I hope these are not cases of RTFM.

Portaudio with ALSA cmipci-driver

With a freshly rebooted kernel I’m pretty quickly seeing these messages in /var/log/message.

pulseaudio[4338]: alsa-util.c: Dies ist wahrscheinlich ein Fehler im ALSA-Treiber 'snd_cmipci'. Bitte melden Sie diesen Punkt den ALSA-Entwicklern.
pulseaudio[4338]: alsa-util.c: snd_pcm_dump():
pulseaudio[4338]: alsa-util.c: Hardware PCM card 0 'C-Media CMI8738' device 0 subdevice 0
pulseaudio[4338]: alsa-util.c: Its setup is:
pulseaudio[4338]: alsa-util.c:   stream       : PLAYBACK
pulseaudio[4338]: alsa-util.c:   access       : MMAP_INTERLEAVED
pulseaudio[4338]: alsa-util.c:   format       : S16_LE
pulseaudio[4338]: alsa-util.c:   subformat    : STD
pulseaudio[4338]: alsa-util.c:   channels     : 2
pulseaudio[4338]: alsa-util.c:   rate         : 44100
pulseaudio[4338]: alsa-util.c:   exact rate   : 44100 (44100/1)
pulseaudio[4338]: alsa-util.c:   msbits       : 16
pulseaudio[4338]: alsa-util.c:   buffer_size  : 16384
pulseaudio[4338]: alsa-util.c:   period_size  : 8192
pulseaudio[4338]: alsa-util.c:   period_time  : 185759
pulseaudio[4338]: alsa-util.c:   tstamp_mode  : ENABLE
pulseaudio[4338]: alsa-util.c:   period_step  : 1
pulseaudio[4338]: alsa-util.c:   avail_min    : 15503
pulseaudio[4338]: alsa-util.c:   period_event : 0
pulseaudio[4338]: alsa-util.c:   start_threshold  : -1
pulseaudio[4338]: alsa-util.c:   stop_threshold   : 1073741824
pulseaudio[4338]: alsa-util.c:   silence_threshold: 0
pulseaudio[4338]: alsa-util.c:   silence_size : 0
pulseaudio[4338]: alsa-util.c:   boundary     : 1073741824
pulseaudio[4338]: alsa-util.c:   appl_ptr     : 231533
pulseaudio[4338]: alsa-util.c:   hw_ptr       : 212998

I think with Linux 2.6.30 I experienced these problem for the first time, both for the onboard 82801EB/ER (ICH5/ICH5R) audio controller and the add-on C-Media CM8738 controller. Since then I’ve been reinstalling the ALSA driver 1.0.20 from http://www.alsa-project.org each time I recompiled a new kernel. 1.0.21 showed the same problem. Pulseaudio progessed in this period from 0.9.15 to 0.9.21, the latest being the one I’m currently using.

What changed with 2.6.32 however is, that onboard 82801EB/ER (ICH5/ICH5R) now appears to be working. After listening with onboard audio for a bit, I remembered, why I installed an elcheapo PCI-card. The onboard audio carries such an amount of noise, that it is unbearable.

NFS

When I tried to mount a locally exported file system on a remote system, these segmentation fault showed up in /var/log/messages:

kernel: rpc.mountd[3885]: segfault at 13 ip 0804c133 sp bfc98530 error 4 in rpc.mountd[8048000+12000]

This could be fixed be recompiling net-fs/nfs-utils-1.2.1.

ACPI-Wakup

I’m using the below command sequence to let my PC wake-up and boot at 7:15 in the morning, so that it’s ready, when I come into the company. This worked flawlessly until I switched to 2.6.32.

# echo 0 > /sys/class/rtc/rtc0/wakealarm
# echo $(date -u '+%s' -d 'tomorrow 7:15') > /sys/class/rtc/rtc0/wakealarm
# cat /proc/driver/rtc 
rtc_time    : 17:07:41
rtc_date    : 2009-12-11
alrm_time   : 07:15:00
alrm_date   : 2009-12-12
alarm_IRQ   : yes
alrm_pending    : no
24hr        : yes
periodic_IRQ    : no
update_IRQ  : no
HPET_emulated   : yes
DST_enable  : no
periodic_freq   : 1024
batt_status : okay

Here is someone, who apparently experiences this as well.

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