[alsa-devel] [PATCH] ALSA: usb-audio: fix missing input volume controls in MAYA44 USB(+)

[Takashi Iwai]

At Wed, 03 Jun 2015 11:36:51 +0200,
Clemens Ladisch wrote:
> 
> The driver worked around an error in the MAYA44 USB(+)'s mixer unit
> descriptor by aborting before parsing the missing field.  However,
> aborting parsing too early prevented parsing of the other units
> connected to this unit, so the capture mixer controls would be missing.
> 
> Fix this by moving the check for this descriptor error after the parsing
> of the unit's input pins.
> 
> Reported-by: nightmixes <nightmixes at gmail.com>
> Tested-by: nightmixes <nightmixes at gmail.com>
> Signed-off-by: Clemens Ladisch <clemens at ladisch.de>

Applied, thanks.


Takashi

> 
> --- a/sound/usb/mixer.c
> +++ b/sound/usb/mixer.c
> @@ -1583,18 +1583,15 @@ static int parse_audio_mixer_unit(struct
>  			      unitid);
>  		return -EINVAL;
>  	}
> -	/* no bmControls field (e.g. Maya44) -> ignore */
> -	if (desc->bLength <= 10 + input_pins) {
> -		usb_audio_dbg(state->chip, "MU %d has no bmControls field\n",
> -			      unitid);
> -		return 0;
> -	}
> 
>  	num_ins = 0;
>  	ich = 0;
>  	for (pin = 0; pin < input_pins; pin++) {
>  		err = parse_audio_unit(state, desc->baSourceID[pin]);
>  		if (err < 0)
> +			continue;
> +		/* no bmControls field (e.g. Maya44) -> ignore */
> +		if (desc->bLength <= 10 + input_pins)
>  			continue;
>  		err = check_input_term(state, desc->baSourceID[pin], &iterm);
>  		if (err < 0)
>