From: Takashi Sakamoto <o-takashi@sakamocchi.jp> 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> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- 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 a63fcbc..02f4a83 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; + } } } -- 1.8.3