PCM: A bugfix that was reintroduced in r4352:

After this change, the echo-canceler buffers were not cleared
in some cases. As a result when one FXS is put ONHOOK, the other side 
could hear noise for a second or two until full disconnect is done.


git-svn-id: http://svn.digium.com/svn/zaptel/branches/1.2@4407 5390a7c7-147a-4af0-8ec9-7488f05a26cb

1 files changed, 18 insertions, 11 deletions

diff --git a/xpp/xbus-pcm.c b/xpp/xbus-pcm.c
index 644f1b9..ff4bee1 100644
--- a/xpp/xbus-pcm.c
+++ b/xpp/xbus-pcm.c
@@ -865,23 +865,30 @@ void generic_card_pcm_tospan(xbus_t *xbus, xpd_t *xpd, xpacket_t *pack)
 	pcm = RPACKET_FIELD(pack, GLOBAL, PCM_READ, pcm);
 	pcm_mask = RPACKET_FIELD(pack, GLOBAL, PCM_READ, lines);
 	spin_lock_irqsave(&xpd->lock, flags);
-	pcm_mute = xpd->mute_dtmf | xpd->silence_pcm;
+	/*
+	 * Calculate the channels we want to mute
+	 */
+	pcm_mute = ~xpd->wanted_pcm_mask;
+	pcm_mute |= xpd->mute_dtmf | xpd->silence_pcm;
 	if(!SPAN_REGISTERED(xpd))
 		goto out;
 	for (i = 0; i < xpd->channels; i++) {
 		volatile u_char	*r = xpd->span.chans[i].readchunk;
 		bool		got_data = IS_SET(pcm_mask, i);
 
-		if(IS_SET(xpd->wanted_pcm_mask, i)) {
-			/* Must fill zaptel buffers */
-			if(got_data && !IS_SET(pcm_mute, i)) {
-				/* We have and want real data */
-				// memset((u_char *)r, 0x5A, ZT_CHUNKSIZE);	// DEBUG
-				// fill_beep((u_char *)r, 1, 1);	// DEBUG: BEEP
-				memcpy((u_char *)r, pcm, ZT_CHUNKSIZE);
-			} else {
-				/* Inject SILENCE */
-				memset((u_char *)r, 0x7F, ZT_CHUNKSIZE);
+		if(got_data && !IS_SET(pcm_mute, i)) {
+			/* We have and want real data */
+			// memset((u_char *)r, 0x5A, ZT_CHUNKSIZE);	// DEBUG
+			// fill_beep((u_char *)r, 1, 1);	// DEBUG: BEEP
+			memcpy((u_char *)r, pcm, ZT_CHUNKSIZE);
+		} else if(IS_SET(xpd->wanted_pcm_mask | xpd->silence_pcm, i)) {
+			/* Inject SILENCE */
+			memset((u_char *)r, 0x7F, ZT_CHUNKSIZE);
+			if(IS_SET(xpd->silence_pcm, i)) {
+				/*
+				 * This will clear the EC buffers until next tick
+				 * So we don't have noise residues from the past.
+				 */
 				memset(xpd->ec_chunk2[i], 0x7F, ZT_CHUNKSIZE);
 				memset(xpd->ec_chunk1[i], 0x7F, ZT_CHUNKSIZE);
 			}