[alsa-devel] [PATCH 1/3] dice: fix fallback from protocol extension into limited functionality

[Takashi Sakamoto]

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 at vger.kernel.org> # v4.18+
Fixes: 58579c056c1c9 ("ALSA: dice: use extended protocol to detect available stream formats")
Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 sound/firewire/dice/dice-extension.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sound/firewire/dice/dice-extension.c b/sound/firewire/dice/dice-extension.c
index a63fcbc875ad..02f4a8318e38 100644
--- 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;
+			}
 		}
 	}
 
-- 
2.20.1