diff --git a/sys/dev/sound/pci/hdspe-pcm.c b/sys/dev/sound/pci/hdspe-pcm.c
--- a/sys/dev/sound/pci/hdspe-pcm.c
+++ b/sys/dev/sound/pci/hdspe-pcm.c
@@ -540,7 +540,8 @@
 	struct sc_pcminfo *scp;
 	struct sc_info *sc;
 	uint32_t row, ports;
-	unsigned int pos;
+	uint32_t dma_pos;
+	unsigned int pos, length, offset;
 	unsigned int n;
 	unsigned int adat_width, pcm_width;
 
@@ -558,13 +559,35 @@
 	else
 		pcm_width = 8;
 
-	if (ch->dir == PCMDIR_PLAY)
-		pos = sndbuf_getreadyptr(ch->buffer);
-	else
-		pos = sndbuf_getfreeptr(ch->buffer);
+	/* Derive buffer position and length to be copied. */
+	if (ch->dir == PCMDIR_PLAY) {
+		/* Position per channel is n times smaller than PCM. */
+		pos = sndbuf_getreadyptr(ch->buffer) / n;
+		length = sndbuf_getready(ch->buffer) / n;
+		/* Copy no more than 2 periods in advance. */
+		if (length > (sc->period * 4 * 2))
+			length = (sc->period * 4 * 2);
+		/* Skip what was already copied last time. */
+		offset = (ch->position + HDSPE_CHANBUF_SIZE) - pos;
+		offset %= HDSPE_CHANBUF_SIZE;
+		if (offset <= length) {
+			pos = (pos + offset) % HDSPE_CHANBUF_SIZE;
+			length -= offset;
+		}
+	} else {
+		/* Position per channel is n times smaller than PCM. */
+		pos = sndbuf_getfreeptr(ch->buffer) / n;
+		/* Get DMA buffer write position. */
+		dma_pos = hdspe_read_2(sc, HDSPE_STATUS_REG);
+		dma_pos &= HDSPE_BUF_POSITION_MASK;
+		/* Copy what is newly available. */
+		length = (dma_pos + HDSPE_CHANBUF_SIZE) - pos;
+		length %= HDSPE_CHANBUF_SIZE;
+	}
 
-	pos /= 4; /* Bytes per sample. */
-	pos /= n; /* Destination buffer n-times smaller. */
+	/* Position and length in samples (4 bytes). */
+	pos /= 4;
+	length /= 4;
 
 	/* Iterate through rows of ports with contiguous slots. */
 	ports = ch->ports;
@@ -576,10 +599,10 @@
 	while (row != 0) {
 		if (ch->dir == PCMDIR_PLAY)
 			buffer_mux_port(sc->pbuf, ch->data, row, ch->ports, pos,
-			    sc->period * 2, adat_width, pcm_width);
+			    length, adat_width, pcm_width);
 		else
 			buffer_demux_port(sc->rbuf, ch->data, row, ch->ports,
-			    pos, sc->period * 2, adat_width, pcm_width);
+			    pos, length, adat_width, pcm_width);
 
 		ports &= ~row;
 		if (pcm_width == adat_width)
@@ -587,6 +610,8 @@
 		else
 			row = hdspe_port_first(ports);
 	}
+
+	ch->position = ((pos + length) * 4) % HDSPE_CHANBUF_SIZE;
 }
 
 static int
@@ -620,6 +645,8 @@
 		row = hdspe_port_first_row(ports);
 	}
 
+	ch->position = 0;
+
 	return (0);
 }
 
@@ -664,6 +691,7 @@
 	/* Allocate maximum buffer size. */
 	ch->size = HDSPE_CHANBUF_SIZE * hdspe_channel_count(ch->ports, 8);
 	ch->data = malloc(ch->size, M_HDSPE, M_NOWAIT);
+	ch->position = 0;
 
 	ch->buffer = b;
 	ch->channel = c;
diff --git a/sys/dev/sound/pci/hdspe.h b/sys/dev/sound/pci/hdspe.h
--- a/sys/dev/sound/pci/hdspe.h
+++ b/sys/dev/sound/pci/hdspe.h
@@ -184,6 +184,7 @@
 	/* Buffer */
 	uint32_t	*data;
 	uint32_t	size;
+	uint32_t	position;
 
 	/* Flags */
 	uint32_t	run;