regression on imac G3: problems with sound

[Takashi Iwai]

At Wed, 1 Oct 2008 23:47:34 +0300,
risto.suominen at gmail.com wrote:
> 
> 2008/10/1, Mariusz Kozlowski <m.kozlowski at tuxland.pl>:
> > Hello,
> >
> > 	I found that on my old iMac G3 aumix behaves weird on newer (up to
> > 2.6.27-rc8) kernels. The sound is only present _when_ muted and is quiet
> > I'd say 10% of 'normal' max level. If you turn the volume up - the box is
> > silent.
> > If you unmute - the box is silent. 100% reproducible.
> >
> > Bisection result is a bit surprising as it seems it was introduced some time
> > ago,
> > in 2.6.25 ~ 2.6.26-rc1 window:
> >
> > commit a8c2a6bf464d983c642c8b8b001a57aabbf76673
> > Author: Risto Suominen <Risto.Suominen at gmail.com>
> > Date:   Thu Apr 17 17:55:30 2008 +0200
> >
> >     [ALSA] snd-powermac: AWACS and Screamer mixers for PM7500, Beige, and
> > iMac SL
> >
> >     Add mixer controls and correct headphone detection bits for PowerMacs
> >     7300/7500 (AWACS) and G3 Beige (Screamer), and iMac G3 Slot-loading
> >     (Screamer).
> >
> >
> > 	Mariusz
> >
> >
> >
> > processor       : 0
> > cpu             : 740/750
> > temperature     : 52 C (uncalibrated)
> > clock           : 400.000000MHz
> > revision        : 2.2 (pvr 0008 0202)
> > bogomips        : 49.79
> > timebase        : 24967326
> > platform        : PowerMac
> > model           : PowerMac2,1
> > machine         : PowerMac2,1
> > motherboard     : PowerMac2,1 MacRISC2 MacRISC Power Macintosh
> > detected as     : 66 (iMac FireWire)
> > pmac flags      : 00000014
> > L2 cache        : 512K unified
> > pmac-generation : NewWorld
> >
> > 0000:00:0b.0 Host bridge: Apple Computer Inc. UniNorth AGP
> > 0000:00:10.0 Display controller: ATI Technologies Inc Rage 128 RL/VR AGP
> > 0001:10:0b.0 Host bridge: Apple Computer Inc. UniNorth PCI
> > 0001:10:12.0 FireWire (IEEE 1394): Texas Instruments TSB12LV23 IEEE-1394
> > Controller
> > 0001:10:13.0 Ethernet controller: Digital Equipment Corporation DECchip
> > 21142/43 (rev 41)
> > 0001:10:17.0 Class ff00: Apple Computer Inc. KeyLargo Mac I/O (rev 02)
> > 0001:10:18.0 USB Controller: Apple Computer Inc. KeyLargo USB
> > 0001:10:19.0 USB Controller: Apple Computer Inc. KeyLargo USB
> > 0002:20:0b.0 Host bridge: Apple Computer Inc. UniNorth Internal PCI
> >
> >
> Mariusz, thank you for the report. This is my fault. Sorry.
> 
> PowerMac2,1 seems to have the mute bit reversed compared to later
> models, PowerMac2,2 and PowerMac4,1, which I was using for testing my
> changes.
> 
> This has been fixed in a later patch that should be included in kernel
> 2.6.27, I believe.
> 
> Takashi, when was this (or will be) included? I sent two patches on 2008-08-25.

No, it wasn't because it's not clear whether the patches are
regression fixes.

Mariusz, try sound git tree.  Risto's patches are already there.
    git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6.git
    
If it works, then try to cherry-pick the following two commits onto
the vanilla kernel:
- 8352a6fe67a0f804302b93178f2e13b66004a693
      ALSA: snd-powermac: mixers for PowerMac G4 AGP
- e25ae4fd3ccba79cfd5628642754a145394225f6
      ALSA: snd-powermac: HP detection for 1st iMac G3 SL

thanks,

Takashi