[PATCH 5.10 557/593] ALSA: firewire-lib: Fix amdtp_domain_start() when no AMDTP_OUT_STREAM stream is found

From: Greg Kroah-Hartman
Date: Mon Jul 12 2021 - 03:15:16 EST


From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

[ Upstream commit 0cbbeaf370221fc469c95945dd3c1198865c5fe4 ]

The intent here is to return an error code if we don't find what we are
looking for in the 'list_for_each_entry()' loop.

's' is not NULL if the list is empty or if we scan the complete list.
Introduce a new 'found' variable to handle such cases.

Fixes: 60dd49298ec5 ("ALSA: firewire-lib: handle several AMDTP streams in callback handler of IRQ target")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Acked-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/9c9a53a4905984a570ba5672cbab84f2027dedc1.1624560484.git.christophe.jaillet@xxxxxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
sound/firewire/amdtp-stream.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index 5805c5de39fb..7a282d8e7148 100644
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -1404,14 +1404,17 @@ int amdtp_domain_start(struct amdtp_domain *d, unsigned int ir_delay_cycle)
unsigned int queue_size;
struct amdtp_stream *s;
int cycle;
+ bool found = false;
int err;

// Select an IT context as IRQ target.
list_for_each_entry(s, &d->streams, list) {
- if (s->direction == AMDTP_OUT_STREAM)
+ if (s->direction == AMDTP_OUT_STREAM) {
+ found = true;
break;
+ }
}
- if (!s)
+ if (!found)
return -ENXIO;
d->irq_target = s;

--
2.30.2