| Message ID | 9c9a53a4905984a570ba5672cbab84f2027dedc1.1624560484.git.christophe.jaillet@wanadoo.fr |
|---|---|
| State | Accepted |
| Commit | 0cbbeaf370221fc469c95945dd3c1198865c5fe4 |
| Headers | show |
| Series | ALSA: firewire-lib: Fix 'amdtp_domain_start()' when no AMDTP_OUT_STREAM stream is found | expand |
On Fri, Jun 25, 2021 at 06:05:50AM +0900, Takashi Sakamoto wrote: > > In kernel v5.10 or later, we can use 'list_entry_is_head()' macro added > by a commit e130816164e2 ("include/linux/list.h: add a macro to test if > entry is pointing to the head"). Someone needs to backport that all the way back... regards, dan carpenter
diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c index aad9778d1c4d..9be2260e4ca2 100644 --- a/sound/firewire/amdtp-stream.c +++ b/sound/firewire/amdtp-stream.c @@ -1943,6 +1943,7 @@ int amdtp_domain_start(struct amdtp_domain *d, unsigned int tx_init_skip_cycles, unsigned int events_per_period = d->events_per_period; unsigned int queue_size; struct amdtp_stream *s; + bool found = false; int err; if (replay_seq) { @@ -1955,10 +1956,12 @@ int amdtp_domain_start(struct amdtp_domain *d, unsigned int tx_init_skip_cycles, // 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;
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@wanadoo.fr> --- We could test with" if (list_entry_is_head(s, &d->streams, list))" instead, but I find it much less readable. --- sound/firewire/amdtp-stream.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)