Intel HDA/AD1986A without surround

Hello!

It seems the AD1986A patch (file sound/pci/hda/patch_analog.c) does not provide the AD1986A_SURR_DAC and AD1986A_CLFE_DAC channels on my laptop, where /proc/asound/Intel/codec#0 gives the following info:
Codec: Analog Devices AD1986A
Address: 0
Vendor Id: 0x11d41986
Subsystem Id: 0x0
Revision Id: 0x100400

Playing sound usually fails completely (in 2.6.12 up to 2.6.14 kernels) but works with the attached patch, which simply disables the two surround channels. This has been tested by at least three persons around the net who own the "Amilo Pro V2040" laptop.

Of course, this patch can not be included in the kernel as-is. I guess there are basically two options:
* turn support for the two extra channels into a config and module option, or
* somehow detect whether a given patch supports them.
The second option is probably the better, but unfortunately I don't know how to detect it. (Maybe the numbers above help?) In my opinion at least stereo sound should work out of the box, but surround sound does not necessarily have to. If you need more information on this, please tell me (cc please; I'm not subscribed).

Thank you.

P.S.: This is the relevant entry given by lspci -vvv:
0000:00:1b.0 0403: Intel Corporation 82801FB/FBM/FR/FW/FRW (ICH6 Family) High Definition Audio Controller (rev 04)
Subsystem: Wistron Corp.: Unknown device 2017
Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop-
ParErr- Stepping- SERR- FastB2B-
Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort-
<TAbort- <MAbort- >SERR- <PERR-

       Latency: 0, Cache Line Size: 0x08 (32 bytes)
       Interrupt: pin A routed to IRQ 22
       Region 0: Memory at b0000000 (64-bit, non-prefetchable) 

[size=16K]
Capabilities: [50] Power Management version 2
Flags: PMEClk- DSI- D1- D2- AuxCurrent=55mA PME(D0
+,D1-,D2-,D3hot+,D3cold+)
Status: D0 PME-Enable- DSel=0 DScale=0 PME-
Capabilities: [60] Message Signalled Interrupts: 64bit+
Queue=0/0 Enable-

               Address: 0000000000000000  Data: 0000
       Capabilities: [70] #10 [0091]

Sebastian Reichelt

@@ -1704,15 +1704,6 @@
 	if (mout->hp_nid)
 		/* headphone out will just decode front left/right (stereo) */
 		snd_hda_codec_setup_stream(codec, mout->hp_nid, stream_tag, 0, format);
-	/* surrounds */
-	for (i = 1; i < mout->num_dacs; i++) {
-		if (chs >= (i + 1) * 2) /* independent out */
-			snd_hda_codec_setup_stream(codec, nids[i], stream_tag, i * 2,
-						   format);
-		else /* copy front */
-			snd_hda_codec_setup_stream(codec, nids[i], stream_tag, 0,
-						   format);
-	}
 	return 0;
 }
 

@@ -1724,10 +1715,9 @@
 	hda_nid_t *nids = mout->dac_nids;
 	int i;
 
-	for (i = 0; i < mout->num_dacs; i++)
-		snd_hda_codec_setup_stream(codec, nids[i], 0, 0, 0);
 	if (mout->hp_nid)
 		snd_hda_codec_setup_stream(codec, mout->hp_nid, 0, 0, 0);
+	snd_hda_codec_setup_stream(codec, nids[HDA_FRONT], 0, 0, 0);
 	down(&codec->spdif_mutex);
 	if (mout->dig_out_nid && mout->dig_out_used == HDA_DIG_ANALOG_DUP) {
 		snd_hda_codec_setup_stream(codec, mout->dig_out_nid, 0, 0, 0);