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

commit ea114fc27dc0cb9a550b6add5426720feb66262a upstream.

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>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index b4283660d430f5ec850832a5460cc6aff2de7dde..f6d4967a652a85e5a51575bfe2b233a7ff1d6097 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;