Re: [PATCH 4/6] ALSA: hda: Keep the controller initialization even if no codecs found

[Roy Spliet <nouveau@spliet.org>]

Op 13-04-2020 om 09:20 schreef Takashi Iwai:
> Currently, when the HD-audio controller driver doesn't detect any
> codecs, it tries to abort the probe.  But this abort happens at the
> delayed probe, i.e. the primary probe call already returned success,
> hence the driver is never unbound until user does so explicitly.
> As a result, it may leave the HD-audio device in the running state
> without the runtime PM.  More badly, if the device is a HD-audio bus
> that is tied with a GPU, GPU cannot reach to the full power down and
> consumes unnecessarily much power.
> 
> This patch changes the logic after no-codec situation; it continues
> probing without the further codec initialization but keep the
> controller driver running normally.
> 
> BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=207043
> Signed-off-by: Takashi Iwai <tiwai@suse.de>

Tested-by: Roy Spliet <nouveau@spliet.org>

> ---
>   sound/pci/hda/hda_intel.c | 12 +++++++-----
>   1 file changed, 7 insertions(+), 5 deletions(-)
> 
> diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> index 692857904d49..aa0be85614b6 100644
> --- a/sound/pci/hda/hda_intel.c
> +++ b/sound/pci/hda/hda_intel.c
> @@ -2009,7 +2009,7 @@ static int azx_first_init(struct azx *chip)
>   	/* codec detection */
>   	if (!azx_bus(chip)->codec_mask) {
>   		dev_err(card->dev, "no codecs found!\n");
> -		return -ENODEV;
> +		/* keep running the rest for the runtime PM */
>   	}
>   
>   	if (azx_acquire_irq(chip, 0) < 0)
> @@ -2303,9 +2303,11 @@ static int azx_probe_continue(struct azx *chip)
>   #endif
>   
>   	/* create codec instances */
> -	err = azx_probe_codecs(chip, azx_max_codecs[chip->driver_type]);
> -	if (err < 0)
> -		goto out_free;
> +	if (bus->codec_mask) {
> +		err = azx_probe_codecs(chip, azx_max_codecs[chip->driver_type]);
> +		if (err < 0)
> +			goto out_free;
> +	}
>   
>   #ifdef CONFIG_SND_HDA_PATCH_LOADER
>   	if (chip->fw) {
> @@ -2319,7 +2321,7 @@ static int azx_probe_continue(struct azx *chip)
>   #endif
>   	}
>   #endif
> -	if ((probe_only[dev] & 1) == 0) {
> +	if (bus->codec_mask && !(probe_only[dev] & 1)) {
>   		err = azx_codec_configure(chip);
>   		if (err < 0)
>   			goto out_free;
>