2 files changed, 31 insertions, 7 deletions

diff --git a/sound/pci/au88x0/au88x0_core.c b/sound/pci/au88x0/au88x0_core.c
index 23f49f356e0f..16c0bdfbb164 100644
--- a/sound/pci/au88x0/au88x0_core.c
+++ b/sound/pci/au88x0/au88x0_core.c
@@ -1252,11 +1252,19 @@ static void vortex_adbdma_resetup(vortex_t *vortex, int adbdma) {
 static int inline vortex_adbdma_getlinearpos(vortex_t * vortex, int adbdma)
 {
 	stream_t *dma = &vortex->dma_adb[adbdma];
-	int temp;
+	int temp, page, delta;
 
 	temp = hwread(vortex->mmio, VORTEX_ADBDMA_STAT + (adbdma << 2));
-	temp = (dma->period_virt * dma->period_bytes) + (temp & (dma->period_bytes - 1));
-	return temp;
+	page = (temp & ADB_SUBBUF_MASK) >> ADB_SUBBUF_SHIFT;
+	if (dma->nr_periods >= 4)
+		delta = (page - dma->period_real) & 3;
+	else {
+		delta = (page - dma->period_real);
+		if (delta < 0)
+			delta += dma->nr_periods;
+	}
+	return (dma->period_virt + delta) * dma->period_bytes
+		+ (temp & (dma->period_bytes - 1));
 }
 
 static void vortex_adbdma_startfifo(vortex_t * vortex, int adbdma)
diff --git a/sound/pci/au88x0/au88x0_pcm.c b/sound/pci/au88x0/au88x0_pcm.c
index b9d2f202cf9b..5439d662d104 100644
--- a/sound/pci/au88x0/au88x0_pcm.c
+++ b/sound/pci/au88x0/au88x0_pcm.c
@@ -42,11 +42,7 @@ static struct snd_pcm_hardware snd_vortex_playback_hw_adb = {
 	.rate_min = 5000,
 	.rate_max = 48000,
 	.channels_min = 1,
-#ifdef CHIP_AU8830
-	.channels_max = 4,
-#else
 	.channels_max = 2,
-#endif
 	.buffer_bytes_max = 0x10000,
 	.period_bytes_min = 0x1,
 	.period_bytes_max = 0x1000,
@@ -115,6 +111,17 @@ static struct snd_pcm_hardware snd_vortex_playback_hw_wt = {
 	.periods_max = 64,
 };
 #endif
+#ifdef CHIP_AU8830
+static unsigned int au8830_channels[3] = {
+	1, 2, 4,
+};
+
+static struct snd_pcm_hw_constraint_list hw_constraints_au8830_channels = {
+	.count = ARRAY_SIZE(au8830_channels),
+	.list = au8830_channels,
+	.mask = 0,
+};
+#endif
 /* open callback */
 static int snd_vortex_pcm_open(struct snd_pcm_substream *substream)
 {
@@ -156,6 +163,15 @@ static int snd_vortex_pcm_open(struct snd_pcm_substream *substream)
 		if (VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_ADB
 		    || VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_I2S)
 			runtime->hw = snd_vortex_playback_hw_adb;
+#ifdef CHIP_AU8830
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK &&
+			VORTEX_PCM_TYPE(substream->pcm) == VORTEX_PCM_ADB) {
+			runtime->hw.channels_max = 4;
+			snd_pcm_hw_constraint_list(runtime, 0,
+				SNDRV_PCM_HW_PARAM_CHANNELS,
+				&hw_constraints_au8830_channels);
+		}
+#endif
 		substream->runtime->private_data = NULL;
 	}
 #ifndef CHIP_AU8810