Currently, drivers can bring XRUN state for PCM substreams when error to queue packets or detecting discontinuity of packet. The application may try to recover this state by calling snd_pcm_prepare().
Depending on each driver, .prepare() includes restart streaming. Then there is a state that PCM substreams are running but isochronous contexts are stopped. In this case, when .pointer() is called, it refers to error pointer.
This commit is for a prevention of this bug.
Signed-off-by: Takashi Sakamoto o-takashi@sakamocchi.jp --- sound/firewire/amdtp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c index ac8c358..7c814ace 100644 --- a/sound/firewire/amdtp.c +++ b/sound/firewire/amdtp.c @@ -898,7 +898,7 @@ EXPORT_SYMBOL(amdtp_stream_start); unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s) { /* this optimization is allowed to be racy */ - if (s->pointer_flush) + if (s->pointer_flush && amdtp_stream_running(s)) fw_iso_context_flush_completions(s->context); else s->pointer_flush = true;