ALSA: firewire-lib: replace ack callback to flush isoc contexts in AMDTP domain

[linux-2.6-microblaze.git] / sound / firewire / amdtp-stream.c

diff --git a/sound/firewire/amdtp-stream.c b/sound/firewire/amdtp-stream.c
index 23677b8..3d27d4c 100644 (file)
--- a/sound/firewire/amdtp-stream.c
+++ b/sound/firewire/amdtp-stream.c
@@ -1139,23 +1139,29 @@ unsigned long amdtp_domain_stream_pcm_pointer(struct amdtp_domain *d,
 EXPORT_SYMBOL_GPL(amdtp_domain_stream_pcm_pointer);
 
 /**
- * amdtp_stream_pcm_ack - acknowledge queued PCM frames
+ * amdtp_domain_stream_pcm_ack - acknowledge queued PCM frames
+ * @d: the AMDTP domain.
  * @s: the AMDTP stream that transfers the PCM frames
  *
  * Returns zero always.
  */
-int amdtp_stream_pcm_ack(struct amdtp_stream *s)
+int amdtp_domain_stream_pcm_ack(struct amdtp_domain *d, struct amdtp_stream *s)
 {
-       /*
-        * Process isochronous packets for recent isochronous cycle to handle
-        * queued PCM frames.
-        */
-       if (amdtp_stream_running(s))
-               fw_iso_context_flush_completions(s->context);
+       struct amdtp_stream *irq_target = d->irq_target;
+
+       // Process isochronous packets for recent isochronous cycle to handle
+       // queued PCM frames.
+       if (irq_target && amdtp_stream_running(irq_target)) {
+               // Queued packet should be processed without any kernel
+               // preemption to keep latency against bus cycle.
+               preempt_disable();
+               fw_iso_context_flush_completions(irq_target->context);
+               preempt_enable();
+       }
 
        return 0;
 }
-EXPORT_SYMBOL(amdtp_stream_pcm_ack);
+EXPORT_SYMBOL_GPL(amdtp_domain_stream_pcm_ack);
 
 /**
  * amdtp_stream_update - update the stream after a bus reset