SiS7012(snd_ich) and interrupt storms?

Hi,

I installed FreeBSD -CURRENT on a friend's laptop. The laptop has a SiS
7012 audio chip. Whenever I load snd_ich, the machine instantly uses
~20% cpu power for interrupt handling of irq10:pcm (according to top and
systat). Unloading the module brings everything back to normal.

This is /dev/sndstat when the snd_ich is loaded:
FreeBSD Audio Driver (newpcm)
Installed devices:
pcm0: <SiS 7012> at io 0xdc00, 0xd800 irq 10 bufsz 16384 kld snd_ich
(1p/1r/0v channels duplex default)

pciconf:
none1_at_pci0:2:7: class=0x040100 card=0x52031584 chip=0x70121039 rev=0xa0
hdr=0x00
    vendor   = 'Silicon Integrated Systems (SiS)'
    device   = 'SiS7012 PCI Audio Accelerator'
    class    = multimedia
    subclass = audio

Are there any known problems in snd_ich that I should be aware of?

Regards,
Andreas