ALSA: usb-audio: fix missing input volume controls in MAYA44 USB(+)

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@gmail.com>
Tested-by: nightmixes <nightmixes@gmail.com>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 4256fdedbd800938a0f1aa9a6f864e8619df34d7..8b7e391dd0b80193d49f8634bb69fa45814593f0 100644 (file)
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -1583,12 +1583,6 @@ static int parse_audio_mixer_unit(struct mixer_build *state, int unitid,
                              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;
@@ -1596,6 +1590,9 @@ static int parse_audio_mixer_unit(struct mixer_build *state, int unitid,
                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)
                        return err;