[PATCH 4/4] ALSA: pcm: add notes to deprecate snd_pcm_sync_id in PCM interface for user space

[Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>]

In PCM core function, the snd_pcm_sync_id union is not used anymore.

This commit adds some notes about it in UAPI header.

Signed-off-by: Takashi Sakamoto <o-takashi@xxxxxxxxxxxxx>
---
 include/uapi/sound/asound.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
index 628d46a0da92..8252c7ac6896 100644
--- a/include/uapi/sound/asound.h
+++ b/include/uapi/sound/asound.h
@@ -142,7 +142,7 @@ struct snd_hwdep_dsp_image {
  *                                                                           *
  *****************************************************************************/
 
-#define SNDRV_PCM_VERSION		SNDRV_PROTOCOL_VERSION(2, 0, 17)
+#define SNDRV_PCM_VERSION		SNDRV_PROTOCOL_VERSION(2, 0, 18)
 
 typedef unsigned long snd_pcm_uframes_t;
 typedef signed long snd_pcm_sframes_t;
@@ -330,6 +330,7 @@ enum {
 #endif
 };
 
+/* This union is not used anymore since PCM interface version 2.18. */
 union snd_pcm_sync_id {
 	unsigned char id[16];
 	unsigned short id16[8];
@@ -348,7 +349,7 @@ struct snd_pcm_info {
 	int dev_subclass;		/* SNDRV_PCM_SUBCLASS_* */
 	unsigned int subdevices_count;
 	unsigned int subdevices_avail;
-	union snd_pcm_sync_id sync;	/* hardware synchronization ID */
+	union snd_pcm_sync_id sync;	/* Deprecated since PCM interface version 2.18. */
 	unsigned char reserved[64];	/* reserved for future... */
 };
 
-- 
2.43.0