From ddf9599542692ab3747f138ac73a777adde2de64 Mon Sep 17 00:00:00 2001
From: Jaroslav Kysela <perex@perex.cz>
Date: Mon, 23 Oct 2006 11:34:00 +0200
Subject: [PATCH] pcm: fix ipc offset calculation for direct plugins

Also add more accurate description to x24 formats.
---
 include/pcm.h        |  8 ++++----
 src/pcm/pcm_direct.c | 21 ++++++++++++++++++---
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/include/pcm.h b/include/pcm.h
index 5aca759b..23b98aac 100644
--- a/include/pcm.h
+++ b/include/pcm.h
@@ -120,13 +120,13 @@ typedef enum _snd_pcm_format {
 	SND_PCM_FORMAT_U16_LE,
 	/** Unsigned 16 bit Big Endian */
 	SND_PCM_FORMAT_U16_BE,
-	/** Signed 24 bit Little Endian */
+	/** Signed 24 bit Little Endian using low three bytes in 32-bit word */
 	SND_PCM_FORMAT_S24_LE,
-	/** Signed 24 bit Big Endian */
+	/** Signed 24 bit Big Endian using low three bytes in 32-bit word */
 	SND_PCM_FORMAT_S24_BE,
-	/** Unsigned 24 bit Little Endian */
+	/** Unsigned 24 bit Little Endian using low three bytes in 32-bit word */
 	SND_PCM_FORMAT_U24_LE,
-	/** Unsigned 24 bit Big Endian */
+	/** Unsigned 24 bit Big Endian using low three bytes in 32-bit word */
 	SND_PCM_FORMAT_U24_BE,
 	/** Signed 32 bit Little Endian */
 	SND_PCM_FORMAT_S32_LE,
diff --git a/src/pcm/pcm_direct.c b/src/pcm/pcm_direct.c
index 93ff2a98..07567102 100644
--- a/src/pcm/pcm_direct.c
+++ b/src/pcm/pcm_direct.c
@@ -1426,12 +1426,12 @@ static int _snd_pcm_direct_get_slave_ipc_offset(snd_config_t *root,
 						int hop)
 {
 	snd_config_iterator_t i, next;
+	snd_config_t *pcm_conf;
 	int err;
 	long card = 0, device = 0, subdevice = 0;
 	const char *str;
 
 	if (snd_config_get_string(sconf, &str) >= 0) {
-		snd_config_t *pcm_conf;
 		if (hop > SND_CONF_MAX_HOPS) {
 			SNDERR("Too many definition levels (looped?)");
 			return -EINVAL;
@@ -1448,6 +1448,21 @@ static int _snd_pcm_direct_get_slave_ipc_offset(snd_config_t *root,
 		return err;
 	}
 
+#if 0	/* for debug purposes */
+	{
+		snd_output_t *out;
+		snd_output_stdio_attach(&out, stderr, 0);
+		snd_config_save(sconf, out);
+		snd_output_close(out);
+	}
+#endif
+
+	if (snd_config_search(sconf, "slave", &pcm_conf) >= 0 &&
+	    snd_config_search(pcm_conf, "pcm", &pcm_conf) >= 0)
+		return _snd_pcm_direct_get_slave_ipc_offset(root, pcm_conf,
+							    direction,
+							    hop + 1);
+
 	snd_config_for_each(i, next, sconf) {
 		snd_config_t *n = snd_config_iterator_entry(i);
 		const char *id, *str;
@@ -1631,7 +1646,7 @@ int snd_pcm_direct_parse_open_conf(snd_config_t *root, snd_config_t *conf,
 		SNDERR("Unknown field %s", id);
 		return -EINVAL;
 	}
-	if (! rec->slave) {
+	if (!rec->slave) {
 		SNDERR("slave is not defined");
 		return -EINVAL;
 	}
@@ -1641,7 +1656,7 @@ int snd_pcm_direct_parse_open_conf(snd_config_t *root, snd_config_t *conf,
 	}
 	if (ipc_key_add_uid)
 		rec->ipc_key += getuid();
-	err = snd_pcm_direct_get_slave_ipc_offset(root, rec->slave, stream);
+	err = snd_pcm_direct_get_slave_ipc_offset(root, conf, stream);
 	if (err < 0)
 		return err;
 	rec->ipc_key += err;
-- 
2.47.1