[Buildroot] Alsa problem with arm 2.6.23.1 and uclibc

[ing. Federico Fuga <fuga@studiofuga.com>]

Hi,

Do you know of any problem with alsa and uclibc and kernel 2.6.23 on arm?
I built a uclibc buildroot, now all works fine except alsa. Aplay can
see the devices, but alsactl cannot change the mixer levels:

# aplay  -l
**** List of PLAYBACK Hardware Devices ****
card 0: EMX270 [EM-X270], device 0: AC97 HiFi AC97 HiFi-AC97-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: EMX270 [EM-X270], device 1: AC97 Aux AC97 Aux-AC97-1 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
# aplay  -L
default:CARD=EMX270
    EM-X270,
    Default Audio Device
null
    Discard all samples (playback) or generate zero samples (capture)
# alsactl restore
alsactl: set_control:1159: Cannot write control '2:0:0:Speaker Playback
Volume:0' : Inappropriate ioctl for device
# alsactl store -f /root/sample
alsactl: get_control:218: Cannot read control '2,0,0,Speaker Playback
Volume,0': Inappropriate ioctl for device

The devices in /dev/snd seems ok:

# ls /dev/snd/ -l
crw-rw-rw-    1 root     root     116,   0 Dec 31 17:00 controlC0
crw-rw-rw-    1 root     root     116,  24 Dec 31 17:00 pcmC0D0c
crw-rw-rw-    1 root     root     116,  16 Dec 31 17:00 pcmC0D0p
crw-rw-rw-    1 root     root     116,  17 Dec 31 17:00 pcmC0D1p
crw-rw-rw-    1 root     root     116,  33 Dec 31 17:00 timer

The strange thing is that in an Angstrom Linux based on glibc and the
same kernel and alsa-lib/utils/libasound version (same patches, same
all) it works without problems.
last few lines of strace output of alsactl restore :

open("/usr/lib/libasound.so.2", O_RDONLY) = 4
fstat(4, {st_mode=S_IFREG|0755, st_size=959649, ...}) = 0
close(4)                                = 0
open("/dev/snd/controlC0", O_RDONLY)    = 4
close(4)                                = 0
open("/dev/snd/controlC0", O_RDWR)      = 4
ioctl(4, USBDEVFS_CONTROL, 0xbef809cc)  = 0
ioctl(4, UI_DEV_CREATE, 0xbef80ab0)     = 0
ioctl(4, USBDEVFS_CONNECTINFO, 0xbef80634) = 0
ioctl(4, USBDEVFS_HUB_PORTINFO, 0xbef80748) = -1 ENOTTY (Inappropriate
ioctl for device)

Any idea?

Thank you in advance!
best regards,

ing. Federico Fuga