ALSA: dice: fix fallback from protocol extension into limited functionality

commit 3e2dc6bdb56893bc28257e482e1dbe5d39f313df upstream.

At failure of attempt to detect protocol extension, ALSA dice driver
should be fallback to limited functionality. However it's not.

This commit fixes it.

Cc: <stable@vger.kernel.org> # v4.18+
Fixes: 58579c056c1c9 ("ALSA: dice: use extended protocol to detect available stream formats")
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20200113084630.14305-2-o-takashi@sakamocchi.jp
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/sound/firewire/dice/dice-extension.c b/sound/firewire/dice/dice-extension.c
index a63fcbc875adc3b9906f90d13fb3f5c8ea4ebbec..02f4a8318e38e7309da42b3274a59fee95d8349f 100644 (file)
--- a/sound/firewire/dice/dice-extension.c
+++ b/sound/firewire/dice/dice-extension.c
@@ -159,8 +159,11 @@ int snd_dice_detect_extension_formats(struct snd_dice *dice)
                int j;
 
                for (j = i + 1; j < 9; ++j) {
-                       if (pointers[i * 2] == pointers[j * 2])
+                       if (pointers[i * 2] == pointers[j * 2]) {
+                               // Fallback to limited functionality.
+                               err = -ENXIO;
                                goto end;
+                       }
                }
        }