[cadcdev-svn-commits] SF.net SVN: cadcdev: [359] kos/kernel/arch/dreamcast/sound/arm

[<ba...@us...>]

Revision: 359
          http://svn.sourceforge.net/cadcdev/?rev=359&view=rev
Author:   bardtx
Date:     2006-09-17 16:48:43 -0700 (Sun, 17 Sep 2006)

Log Message:
-----------
kos: Patch #1552720 from SourceForge:
As discussed in the latter part of
http://sourceforge.net/mailarchive/message.php?msg_id=30315678.

There's one more thing I wanted to bring up. In FreeSCI I use more than 
two streaming sound channels, but the aica driver only updates the 
current playing position of the first two.

This is easy to fix by changing the "for (i=0; i<2; i++)" line into 
"for (i=0; i<64; i++)" in arm/main.c.

This exposes another problem, however. It seems that a delay is 
necessary between selecting the sound channel, and reading back its 
position. This is arm/aica.c, function aica_get_pos. Without the delay, 
the positions will "trail behind" by two channels (e.g. channel 2 
position is actually that of channel 0, etc). When you're only updating 
two channels you won't notice this as the two channel delay matches the 
numbers of channels, so even though you're reading old data, it'll be 
for the right channel. I hope I'm making sense here. ;) A simple for
(i=0; i<20; i++); loop seems to fix it, but there might be a better way 
to do the delay.

Modified Paths:
--------------
    kos/kernel/arch/dreamcast/sound/arm/aica.c
    kos/kernel/arch/dreamcast/sound/arm/main.c
    kos/kernel/arch/dreamcast/sound/arm/stream.drv

Modified: kos/kernel/arch/dreamcast/sound/arm/aica.c
===================================================================
--- kos/kernel/arch/dreamcast/sound/arm/aica.c	2006-09-17 23:44:08 UTC (rev 358)
+++ kos/kernel/arch/dreamcast/sound/arm/aica.c	2006-09-17 23:48:43 UTC (rev 359)
@@ -207,8 +207,13 @@
 
 /* Get channel position */
 int aica_get_pos(int ch) {
+	int i;
+
 	/* Observe channel ch */
 	SNDREG8(0x280d) = ch;
+
+	/* Wait a while */
+	for (i = 0; i < 20; i++);
 	
 	/* Update position counters */
 	chans[ch].pos = SNDREG32(0x2814) & 0xffff;

Modified: kos/kernel/arch/dreamcast/sound/arm/main.c
===================================================================
--- kos/kernel/arch/dreamcast/sound/arm/main.c	2006-09-17 23:44:08 UTC (rev 358)
+++ kos/kernel/arch/dreamcast/sound/arm/main.c	2006-09-17 23:48:43 UTC (rev 359)
@@ -178,7 +178,7 @@
 	/* Wait for a command */
 	for( ; ; ) {
 		/* Update channel position counters */
-		for (i=0; i<2; i++)
+		for (i=0; i<64; i++)
 			aica_get_pos(i);
 
 		/* Check for a command */

Modified: kos/kernel/arch/dreamcast/sound/arm/stream.drv
===================================================================
(Binary files differ)


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