diff --git a/src/modules/alsa/alsa-sink.c b/src/modules/alsa/alsa-sink.c
index 63674e2..24cde74 100644
--- a/src/modules/alsa/alsa-sink.c
+++ b/src/modules/alsa/alsa-sink.c
@@ -642,7 +642,9 @@ static int mmap_write(struct userdata *u, pa_usec_t *sleep_usec, bool polled, bo
             chunk.length = pa_memblock_get_length(chunk.memblock);
             chunk.index = 0;
 
+            pa_log_debug("[%s]before pa_sink_render_into_full", u->sink->name);
             pa_sink_render_into_full(u->sink, &chunk);
+            pa_log_debug("[%s]after pa_sink_render_into_full", u->sink->name);
             pa_memblock_unref_fixed(chunk.memblock);
 
             if (PA_UNLIKELY((sframes = snd_pcm_mmap_commit(u->pcm_handle, offset, frames)) < 0)) {
@@ -1713,8 +1715,11 @@ static void thread_func(void *userdata) {
             pa_usec_t sleep_usec = 0;
             bool on_timeout = pa_rtpoll_timer_elapsed(u->rtpoll);
 
-            if (u->use_mmap)
+            if (u->use_mmap) {
+                pa_log_debug("[%s]before mmap_write", u->sink->name);
                 work_done = mmap_write(u, &sleep_usec, revents & POLLOUT, on_timeout);
+                pa_log_debug("[%s]after mmap_write", u->sink->name);
+            }
             else
                 work_done = unix_write(u, &sleep_usec, revents & POLLOUT, on_timeout);