[PATCH] ALSA: dice: fix null pointer dereference when node is disconnected

[Takashi Sakamoto]

When node is removed from IEEE 1394 bus, any transaction fails to the node.
In the case, ALSA dice driver doesn't stop isochronous contexts even if
they are running. As a result, null pointer dereference occurs in callback
from the running context.

This commit fixes the bug to release isochronous contexts always.

Cc: <stable at vger.kernel.org> # v5.4 or later
Fixes: e9f21129b8d8 ("ALSA: dice: support AMDTP domain")
Signed-off-by: Takashi Sakamoto <o-takashi at sakamocchi.jp>
---
 sound/firewire/dice/dice-stream.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/sound/firewire/dice/dice-stream.c b/sound/firewire/dice/dice-stream.c
index 8e0c0380b4c4..1a14c083e8ce 100644
--- a/sound/firewire/dice/dice-stream.c
+++ b/sound/firewire/dice/dice-stream.c
@@ -493,11 +493,10 @@ void snd_dice_stream_stop_duplex(struct snd_dice *dice)
 	struct reg_params tx_params, rx_params;
 
 	if (dice->substreams_counter == 0) {
-		if (get_register_params(dice, &tx_params, &rx_params) >= 0) {
-			amdtp_domain_stop(&dice->domain);
+		if (get_register_params(dice, &tx_params, &rx_params) >= 0)
 			finish_session(dice, &tx_params, &rx_params);
-		}
 
+		amdtp_domain_stop(&dice->domain);
 		release_resources(dice);
 	}
 }
-- 
2.27.0