axfer: return ETIMEDOUT when no event occurs after waiter expiration

Although the waiter abstraction handles timeout as success, it should
report for callers to know timeout.

This commit takes the waiter to return -ETIMEDOUT when timeout expires.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

axfer/xfer-libasound.c

@@ -343,29 +343,36 @@ static int prepare_waiter(struct libasound_state *state)
 int xfer_libasound_wait_event(struct libasound_state *state, int timeout_msec,
 			      unsigned short *revents)
 {
-	int err;
+	int count;
 
 	if (state->waiter_type != WAITER_TYPE_DEFAULT) {
 		struct waiter_context *waiter = state->waiter;
+		int err;
 
-		err = waiter_context_wait_event(waiter, timeout_msec);
-		if (err < 0)
-			return err;
+		count = waiter_context_wait_event(waiter, timeout_msec);
+		if (count < 0)
+			return count;
+		if (count == 0 && timeout_msec > 0)
+			return -ETIMEDOUT;
 
 		err = snd_pcm_poll_descriptors_revents(state->handle,
 				waiter->pfds, waiter->pfd_count, revents);
-	} else {
-		err = snd_pcm_wait(state->handle, timeout_msec);
 		if (err < 0)
 			return err;
+	} else {
+		count = snd_pcm_wait(state->handle, timeout_msec);
+		if (count < 0)
+			return count;
+		if (count == 0 && timeout_msec > 0)
+			return -ETIMEDOUT;
 
 		if (snd_pcm_stream(state->handle) == SND_PCM_STREAM_PLAYBACK)
 			*revents = POLLOUT;
 		else
 			*revents = POLLIN;
 	}
 
-	return err;
+	return 0;
 }
 
 static int configure_hw_params(struct libasound_state *state,