[PATCH] Fix Dreamcast DMA issues

["Adrian McMenamin" <lkmladrian@gmail.com>]

The current SH DMA API is somewhat broken, not correctly matching
virtual channel to the correct SH DMAC. This wasn't noticeable when
using g2 DMA for the sound driver - one channel 0 is as good as any
other! - but caused the pvr2 driver to fail.

This patch fixes the pvr2 problem and consequently fixes the sound
driver to ensure it continues to function.

Signed-off by: Adrian McMenamin <adrian@mcmen.demon.co.uk>

diff --git a/arch/sh/drivers/dma/dma-api.c b/arch/sh/drivers/dma/dma-api.c
index cf8e119..76ed816 100644
--- a/arch/sh/drivers/dma/dma-api.c
+++ b/arch/sh/drivers/dma/dma-api.c
@@ -31,8 +31,8 @@ struct dma_info *get_dma_info(unsigned int chan)
 	 * the channel is.
 	 */
 	list_for_each_entry(info, &registered_dmac_list, list) {
-		if ((chan <  info->first_channel_nr) ||
-		    (chan >= info->first_channel_nr + info->nr_channels))
+		if ((chan <  info->first_vchannel_nr) ||
+		    (chan >= info->first_vchannel_nr + info->nr_channels))
 			continue;
 
 		return info;
@@ -82,7 +82,7 @@ struct dma_channel *get_dma_channel(unsigned int chan)
 
 	for (i = 0; i < info->nr_channels; i++) {
 		channel = &info->channels[i];
-		if (channel->chan == chan)
+		if (channel->vchan == chan)
 			return channel;
 	}
 
@@ -369,6 +369,7 @@ int register_dmac(struct dma_info *info)
 	}
 
 	total_channels = get_nr_channels();
+	info->first_vchannel_nr = total_channels;
 	for (i = 0; i < info->nr_channels; i++) {
 		struct dma_channel *chan = &info->channels[i];
 
diff --git a/include/asm-sh/dma.h b/include/asm-sh/dma.h
index 6034d4a..4c75b70 100644
--- a/include/asm-sh/dma.h
+++ b/include/asm-sh/dma.h
@@ -111,6 +111,7 @@ struct dma_info {
 
 	struct list_head list;
 	int first_channel_nr;
+	int first_vchannel_nr;
 };
 
 struct dma_chan_caps {
diff --git a/sound/sh/aica.h b/sound/sh/aica.h
index 8c11e3d..d098baa 100644
--- a/sound/sh/aica.h
+++ b/sound/sh/aica.h
@@ -52,7 +52,7 @@
 #define AICA_CHANNEL1_OFFSET 0x21000
 #define CHANNEL_OFFSET 0x10000
 
-#define AICA_DMA_CHANNEL 0
+#define AICA_DMA_CHANNEL 5
 #define AICA_DMA_MODE 5
 
 #define SND_AICA_DRIVER "AICA"