S/PDIF indication wrong?

Hello!

On my ASUS P5P800-VM motherboard, the onboard AC97-chip (Realtek ALC655) does not indicate that there are any S/PDIF functionality available.

However, the manufacturer (Asus) claim that there are S/PDIF output on the board, and of course there is.

I created a patch that check the PCI subsystem vendor id and device id, and if it's a match to this board it ignores the AC97_EI_SPDIF bit when the controls are built.
This allows me to get the desired S/PDIF output to work just as expected.

I'm not sure this is good practise to just ignore this bit or force the bit to 1?

I have checked the BIOS for settings regarding S/PDIF, but there are none. The only audio setting available is to control if the chip shall be enabled or disabled.

What do you recommend in this case?

At Sat, 19 Aug 2006 09:37:01 +0200,

Quoted 13 lines · Magnus Sandin

Hello!

On my ASUS P5P800-VM motherboard, the onboard AC97-chip (Realtek ALC655) does not indicate that there are any S/PDIF functionality available.

However, the manufacturer (Asus) claim that there are S/PDIF output on the board, and of course there is.

I created a patch that check the PCI subsystem vendor id and device id, and if it's a match to this board it ignores the AC97_EI_SPDIF bit when the controls are built.
This allows me to get the desired S/PDIF output to work just as expected.

Quoted 7 lines

I'm not sure this is good practise to just ignore this bit or force the bit to 1?

I have checked the BIOS for settings regarding S/PDIF, but there are none. The only audio setting available is to control if the chip shall be enabled or disabled.

Well, I'd call it a BIOS bug. But such a thing can always happen, of course...

Quoted 2 lines

What do you recommend in this case?

I think your approach is OK. The only concern is that the board with the same PCI SSID might have a codec without SPDIF, but I guess the probability of this regression is quite low.

So, just send a patch for merging (maybe after 1.0.12 release).

Thanks,

Takashi

Hello!

The attached patch will force building the S/PDIF controls on the PCU SSID for Asus P5P800-VM motherboard, even if the AC97_EI_SPDIF bit is not set.

Is this approach OK or do you guys want to have the check somewhere else?

Signed-off-by Magnus Sandin ([email protected])

At Mon, 21 Aug 2006 22:11:29 +0200,

Quoted 10 lines · Magnus Sandin

Hello!

The attached patch will force building the S/PDIF controls on the PCU SSID for Asus P5P800-VM motherboard, even if the AC97_EI_SPDIF bit is not set.

Is this approach OK or do you guys want to have the check somewhere else?

Signed-off-by Magnus Sandin ([email protected])

I prefer the one like below. Could you check whether it works?

Takashi

diff -r 2359af36395e pci/ac97/ac97_codec.c

pci/ac97/ac97_codec.c +0 -0

@@ -1573,6 +1573,12 @@ static int snd_ac97_mixer_build(struct s
 	}
 

I can confirm that that approach works as well!

Will this patch go into 1.0.12?

Regards
// Magnus Sandin

Quoted 26 lines · Takashi Iwai

At Mon, 21 Aug 2006 22:11:29 +0200,

Quoted 10 lines · Magnus Sandin

Hello!

The attached patch will force building the S/PDIF controls on the PCU SSID for Asus P5P800-VM motherboard, even if the AC97_EI_SPDIF bit is not set.

Is this approach OK or do you guys want to have the check somewhere else?

Signed-off-by Magnus Sandin ([email protected])

I prefer the one like below. Could you check whether it works?

Takashi

diff -r 2359af36395e pci/ac97/ac97_codec.c

pci/ac97/ac97_codec.c +0 -0

@@ -1573,6 +1573,12 @@ static int snd_ac97_mixer_build(struct s
 	}
 

pci/ac97/ac97_codec.c static int snd_ac97_mixer_build(struct s · line 1584

Quoted 10 lines

pci/ac97/ac97_codec.c +6 -0

 	/* build S/PDIF controls */
+
+	/* Hack for ASUS P5P800-VM, which does not indicate S/PDIF capability */
+	if (ac97->subsystem_vendor == 0x1043 &&
+	    ac97->subsystem_device == 0x810f)
+		ac97->ext_id |= AC97_EI_SPDIF;
+
 	if ((ac97->ext_id & AC97_EI_SPDIF) && !(ac97->scaps & AC97_SCAP_NO_SPDIF)) {
 		if (ac97->build_ops->build_spdif) {
 			if ((err = ac97->build_ops->build_spdif(ac97)) < 0)

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