Audio fixes, round 1 (inspired in large part by openbsd changes by Jacob
Mauser) 

1284: audio_init_ringbuffer() can be called at times when the pause
      attribute must not be reset.

1702: respect the pause attribute prior to audiostartr(sc)

1759: The audio_clear() function seems to be called in nearly all the
      places where the pause attribute should be reset, so add this here.

2313: Poll conditions should match those found elsewhere!  Prior to this change,
      audio_poll was quite problematic for me.

2205: We have an AUDIO_WSEEK ioctl, so why not AUDIO_RSEEK?  It's easy,
      cheap, and consistent.  (If no one objects this will be ioctl 36).

2960: the pause attribute defaults to false! (I was not 100% sure about this
      one, but I have tested it extensively and found no untoward effects)

4050: In audio_resume(), be sure to heed the pause attribute.


--- sys/dev/audio.c.orig	2008-05-05 18:33:03.000000000 -0400
+++ sys/dev/audio.c	2008-04-30 23:08:50.000000000 -0400
@@ -1284,7 +1284,6 @@
 	rp->stamp_last = 0;
 	rp->fstamp = 0;
 	rp->drops = 0;
-	rp->pause = false;
 	rp->copying = false;
 	rp->needfill = false;
 	rp->mmapped = false;
@@ -1702,7 +1701,7 @@
 	while (uio->uio_resid > 0 && !error) {
 		s = splaudio();
 		while ((used = audio_stream_get_used(sc->sc_rustream)) <= 0) {
-			if (!sc->sc_rbus) {
+			if (!sc->sc_rbus && !sc->sc_rr.pause) {
 				error = audiostartr(sc);
 				if (error) {
 					splx(s);
@@ -1759,11 +1758,13 @@
 		audio_wakeup(&sc->sc_rchan);
 		sc->hw_if->halt_input(sc->hw_hdl);
 		sc->sc_rbus = false;
+		sc->sc_rr.pause = false;
 	}
 	if (sc->sc_pbus) {
 		audio_wakeup(&sc->sc_wchan);
 		sc->hw_if->halt_output(sc->hw_hdl);
 		sc->sc_pbus = false;
+		sc->sc_pr.pause = false;
 	}
 	splx(s);
 }
@@ -2205,6 +2206,10 @@
 		*(u_long *)addr = audio_stream_get_used(sc->sc_pustream);
 		break;
 
+	case AUDIO_RSEEK:
+		*(u_long *)addr = audio_stream_get_used(sc->sc_rustream);
+		break;
+
 	case AUDIO_SETINFO:
 		DPRINTF(("AUDIO_SETINFO mode=0x%x\n", sc->sc_mode));
 		error = audiosetinfo(sc, (struct audio_info *)addr);
@@ -2313,7 +2318,8 @@
 		 * mark.
 		 */
 		if ((!sc->sc_full_duplex && (sc->sc_mode & AUMODE_RECORD)) ||
-		    used <= sc->sc_pr.usedlow)
+		    (!(sc->sc_mode & AUMODE_PLAY_ALL) && sc->sc_playdrop > 0) ||
+		    (used <= sc->sc_pr.usedlow))
 			revents |= events & (POLLOUT | POLLWRNORM);
 	}
 
@@ -2468,13 +2474,13 @@
 					   cb->s.bufsize);
 			s = splaudio();
 			sc->sc_pustream = &cb->s;
-			if (!sc->sc_pbus)
+			if (!sc->sc_pbus && !sc->sc_pr.pause)
 				(void)audiostartp(sc);
 			splx(s);
 		} else {
 			s = splaudio();
 			sc->sc_rustream = &cb->s;
-			if (!sc->sc_rbus)
+			if (!sc->sc_rbus && !sc->sc_rr.pause)
 				(void)audiostartr(sc);
 			splx(s);
 		}
@@ -2960,10 +2966,12 @@
 	ai.record.encoding    = sc->sc_rparams.encoding;
 	ai.record.channels    = sc->sc_rparams.channels;
 	ai.record.precision   = sc->sc_rparams.precision;
+	ai.record.pause	      = false;
 	ai.play.sample_rate   = sc->sc_pparams.sample_rate;
 	ai.play.encoding      = sc->sc_pparams.encoding;
 	ai.play.channels      = sc->sc_pparams.channels;
 	ai.play.precision     = sc->sc_pparams.precision;
+	ai.play.pause         = false;
 	ai.mode		      = mode;
 
 	return audiosetinfo(sc, &ai);
@@ -4050,9 +4058,9 @@
 	if (sc->sc_lastinfovalid)
 		audiosetinfo(sc, &sc->sc_lastinfo);
 	audio_mixer_restore(sc);
-	if (sc->sc_pbus == true)
+	if ((sc->sc_pbus == true) && !sc->sc_pr.pause)
 		audiostartp(sc);
-	if (sc->sc_rbus == true)
+	if ((sc->sc_rbus == true) && !sc->sc_rr.pause)
 		audiostartr(sc);
 	splx(s);