kern/47451: gcscaudio distortion via Sun interface

[jakllsch%kollasch.net@localhost]

>Number:         47451
>Category:       kern
>Synopsis:       gcscaudio(4) reproduces samples too slowly via Sun audio(4) 
>interface but not via ossaudio(3)
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jan 15 06:20:00 +0000 2013
>Originator:     Jonathan A. Kollasch
>Release:        NetBSD 6.0.1
>Organization:
        
>Environment:
        
        
System: NetBSD yonada.kollasch.net 6.0.1 NetBSD 6.0.1 (GENERIC) i386
Architecture: i386
Machine: i386
>Description:

The following hardware (on MSI Fuzzy LX800 board):

gcscaudio0 at pci0 dev 15 function 3: AMD Geode CS5536 Audio
gcscaudio0: interrupting at irq 5
gcscaudio0: ac97: Avance Logic ALC650 codec; 20 bit DAC, 18 bit ADC, Realtek 3D
gcscaudio0: ac97: ext id 0x5c7<AC97_22,LDAC,SDAC,CDAC,SPDIF,DRA,VRA>
audio0 at gcscaudio0: full duplex, playback, capture, mmap, independent

plays samples too slowly via libao-sun, yet libao-oss sounds normal.

audioplay(1) acts similar to libao-sun.

Forcing 6 channel output with audioplay results in a closer to correct rate,
but is still noticably distorted.
>How-To-Repeat:
Attempt to reproduce audio via CS5536+ALC650 using alternatively audio(4) and
ossaudio(3) interfaces.
>Fix:
unknown

>Unformatted: