[PATCH] Fix Dreamcast DMA issues

From: Adrian McMenamin
Date: Mon Jul 23 2007 - 17:05:59 EST

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@xxxxxxxxxxxxxxxxx> 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"