From 175cfc6c883811ec5ad7862a3a5a270a2597e465 Mon Sep 17 00:00:00 2001
From: Adrian Knoth <adi@drcomp.erfurt.thur.de>
Date: Mon, 15 Aug 2011 00:22:54 +0200
Subject: [PATCH] --- yaml --- r: 270405 b: refs/heads/master c:
 2e61027079ed70f54fec41ddb8fa8af37d79d8d8 h: refs/heads/master i:   270403:
 5996e1fca6a444892fc9173700ecea5b9d3185bd v: v3

---
 [refs]                          |  2 +-
 trunk/sound/pci/rme9652/hdspm.c | 25 ++++++++++++++++++++-----
 2 files changed, 21 insertions(+), 6 deletions(-)

diff --git a/[refs] b/[refs]
index 29853bafeafe..9ca8ccbc6c0a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7cb155ff3e4645188c42d707300e36cfce44e28a
+refs/heads/master: 2e61027079ed70f54fec41ddb8fa8af37d79d8d8
diff --git a/trunk/sound/pci/rme9652/hdspm.c b/trunk/sound/pci/rme9652/hdspm.c
index 1a52a1ae1f4c..92ac64ced29a 100644
--- a/trunk/sound/pci/rme9652/hdspm.c
+++ b/trunk/sound/pci/rme9652/hdspm.c
@@ -1323,12 +1323,27 @@ static int hdspm_set_interrupt_interval(struct hdspm *s, unsigned int frames)
 
 	spin_lock_irq(&s->lock);
 
-	frames >>= 7;
-	n = 0;
-	while (frames) {
-		n++;
-		frames >>= 1;
+	if (32 == frames) {
+		/* Special case for new RME cards like RayDAT/AIO which
+		 * support period sizes of 32 samples. Since latency is
+		 * encoded in the three bits of HDSP_LatencyMask, we can only
+		 * have values from 0 .. 7. While 0 still means 64 samples and
+		 * 6 represents 4096 samples on all cards, 7 represents 8192
+		 * on older cards and 32 samples on new cards.
+		 *
+		 * In other words, period size in samples is calculated by
+		 * 2^(n+6) with n ranging from 0 .. 7.
+		 */
+		n = 7;
+	} else {
+		frames >>= 7;
+		n = 0;
+		while (frames) {
+			n++;
+			frames >>= 1;
+		}
 	}
+
 	s->control_register &= ~HDSPM_LatencyMask;
 	s->control_register |= hdspm_encode_latency(n);