From: Andre Noll <maan@systemlinux.org>
Date: Mon, 6 Jun 2011 06:24:08 +0000 (+0200)
Subject: alsa: Avoid busy loop at end of file.
X-Git-Tag: v0.4.8~29^2
X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=commitdiff_plain;h=8a5b6bf798581bdf49e39084f456bce07c01b498

alsa: Avoid busy loop at end of file.

During the drain period at the end of input the status of the alsa
buffer tree node is negative, yet we should not request a minimal
scheduler delay until the end of this period.
---

diff --git a/alsa_write.c b/alsa_write.c
index 047eeaa3..1c168e7b 100644
--- a/alsa_write.c
+++ b/alsa_write.c
@@ -150,8 +150,10 @@ static void alsa_write_pre_select(struct sched *s, struct task *t)
 
 	if (ret == 0)
 		return;
-	if (ret < 0 || !pad)
+	if (!pad)
 		return sched_min_delay(s);
+	if (ret < 0)
+		return sched_request_barrier_or_min_delay(&pad->drain_barrier, s);
 	/*
 	 * Data is available to be written to the alsa handle.  Compute number
 	 * of milliseconds until next buffer underrun would occur.