From 29041c522071172af2c6bf086b3a0c19510a6660 Mon Sep 17 00:00:00 2001
From: "sylvain.bertrand@gmail.com" <sylvain.bertrand@gmail.com>
Date: Tue, 28 Apr 2020 12:09:18 +0000
Subject: [PATCH 20/21] fix infinite draining of the rate plugin in
 SND_PCM_NONBLOCK mode

The draining function of the rate plugin does not handle properly the
SND_PCM_NONBLOCK case. It can write data to the slave plugin each time the
function is called, but does not update its internal state in order to
reach a stopping condition. Use a last_commit_ptr workaround to reach such
condition.

Signed-off-by: Sylvain BERTRAND <sylvain.bertrand@legeek.net>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>
---
 src/pcm/pcm_rate.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/pcm/pcm_rate.c b/src/pcm/pcm_rate.c
index 21611f62c370..4f99a95b325f 100644
--- a/src/pcm/pcm_rate.c
+++ b/src/pcm/pcm_rate.c
@@ -1051,6 +1051,7 @@ static int snd_pcm_rate_drain(snd_pcm_t *pcm)
 		/* commit the remaining fraction (if any) */
 		snd_pcm_uframes_t size, ofs, saved_avail_min;
 		snd_pcm_sw_params_t sw_params;
+		int commit_err;
 
 		__snd_pcm_lock(pcm);
 		/* temporarily set avail_min to one */
@@ -1079,14 +1080,29 @@ static int snd_pcm_rate_drain(snd_pcm_t *pcm)
 				if (! spsize)
 					break;
 			}
-			snd_pcm_rate_commit_area(pcm, rate, ofs,
+			commit_err = snd_pcm_rate_commit_area(pcm, rate, ofs,
 						 psize, spsize);
+			if (commit_err == 1) {
+				rate->last_commit_ptr += psize;
+				if (rate->last_commit_ptr >= pcm->boundary)
+					rate->last_commit_ptr = 0;
+			} else if (commit_err == 0) {
+				if (pcm->mode & SND_PCM_NONBLOCK != 0) {
+					commit_err = -EAGAIN;
+					break;
+				}
+				continue;
+			} else
+				break;
+
 			ofs = (ofs + psize) % pcm->buffer_size;
 			size -= psize;
 		}
 		sw_params.avail_min = saved_avail_min;
 		snd_pcm_sw_params(rate->gen.slave, &sw_params);
 		__snd_pcm_unlock(pcm);
+		if (commit_err < 0)
+			return commit_err;
 	}
 	return snd_pcm_drain(rate->gen.slave);
 }
-- 
2.16.4