Re: [PATCH] ALSA: intel8x0: keep AC97 PCM descriptors for ICH4 capture

[Takashi Iwai <tiwai@suse.de>]

On Wed, 04 Nov 2026 09:22:42 +0100,
raoxu wrote:
> 
> From: Xu Rao <raoxu@uniontech.com>
> 
> When S/PDIF uses the AC-link, spdif_idx is negative and the AC97
> PCM assignment drops its last descriptor.  On ICH4 this leaves five
> entries, but PCM2IN and MIC2 still use entries four and five.
> Opening MIC2 then reads beyond the allocated descriptor array.
> 
> Keep all six descriptors on ICH4 so the capture stream indices stay
> valid.  The S/PDIF descriptor occupies its fixed position but does
> not create a separate hardware PCM when S/PDIF uses the AC-link.
> Other controller types retain their existing descriptor counts.
> 
> Signed-off-by: Xu Rao <raoxu@uniontech.com>
> ---
>  sound/pci/intel8x0.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/sound/pci/intel8x0.c b/sound/pci/intel8x0.c
> index 339024182a26..75db97501c72 100644
> --- a/sound/pci/intel8x0.c
> +++ b/sound/pci/intel8x0.c
> @@ -2291,7 +2291,8 @@ static int snd_intel8x0_mixer(struct intel8x0 *chip, int ac97_clock,
>  	i = ARRAY_SIZE(ac97_pcm_defs);
>  	if (chip->device_type != DEVICE_INTEL_ICH4)
>  		i -= 2;		/* do not allocate PCM2IN and MIC2 */
> -	if (chip->spdif_idx < 0)
> +	/* ICH4 PCM2IN and MIC2 still need entries 4 and 5. */
> +	if (chip->spdif_idx < 0 && chip->device_type != DEVICE_INTEL_ICH4)
>  		i--;		/* do not allocate S/PDIF */

I'd rather move the spdif_idx check into the if block above, i.e.

  	if (chip->device_type != DEVICE_INTEL_ICH4) {
  		i -= 2;		/* do not allocate PCM2IN and MIC2 */
		if (chip->spdif_idx < 0)
	 		i--;	/* do not allocate S/PDIF */
	}

so that it's clearer.
If it's OK, could you resubmit with it?


thanks,

Takashi