From 7b68d92c6224ba23a3250688afbf55c35ab106e4 Mon Sep 17 00:00:00 2001
From: notaz <notasas@gmail.com>
Date: Thu, 8 Sep 2022 18:17:06 +0300
Subject: [PATCH] dma: try more accurate timings

seems to help Legend of Mana
---
 libpcsxcore/cdrom.c  | 16 ++++++++--------
 libpcsxcore/mdec.c   | 35 ++++++++++++++---------------------
 libpcsxcore/psxdma.c |  4 ++--
 3 files changed, 24 insertions(+), 31 deletions(-)

diff --git a/libpcsxcore/cdrom.c b/libpcsxcore/cdrom.c
index 1e435152..bd013e3c 100644
--- a/libpcsxcore/cdrom.c
+++ b/libpcsxcore/cdrom.c
@@ -1462,9 +1462,8 @@ void psxDma3(u32 madr, u32 bcr, u32 chcr) {
 
 	CDR_LOG("psxDma3() Log: *** DMA 3 *** %x addr = %x size = %x\n", chcr, madr, bcr);
 
-	switch (chcr) {
+	switch (chcr & 0x71000000) {
 		case 0x11000000:
-		case 0x11400100:
 			if (cdr.Readed == 0) {
 				CDR_LOG_I("psxDma3() Log: *** DMA 3 *** NOT READY\n");
 				break;
@@ -1493,15 +1492,16 @@ void psxDma3(u32 madr, u32 bcr, u32 chcr) {
 				psxCpu->Clear(madr, size / 4);
 			}
 
-			if( chcr == 0x11400100 ) {
+			CDRDMA_INT((cdsize/4) * 24);
+
+			HW_DMA3_CHCR &= SWAPu32(~0x10000000);
+			if (chcr & 0x100) {
 				HW_DMA3_MADR = SWAPu32(madr + cdsize);
-				CDRDMA_INT( (cdsize/4) / 4 );
+				HW_DMA3_BCR &= SWAPu32(0xffff0000);
 			}
-			else if( chcr == 0x11000000 ) {
-				// CDRDMA_INT( (cdsize/4) * 1 );
+			else {
 				// halted
-				psxRegs.cycle += (cdsize/4) * 24/2;
-				CDRDMA_INT(16);
+				psxRegs.cycle += (cdsize/4) * 24 - 20;
 			}
 			return;
 
diff --git a/libpcsxcore/mdec.c b/libpcsxcore/mdec.c
index 61ed5ea5..4b93ffa5 100644
--- a/libpcsxcore/mdec.c
+++ b/libpcsxcore/mdec.c
@@ -33,12 +33,10 @@
  * so 2.0 to 4.0 should be fine.
  */
  
-/* Was set to 2 before but it would cause issues in R-types and Vandal Hearts videos. 
- * Setting it to 6 as dmitrysmagin did fix those... except for Galerians.
- * Galerians needs this to be set to 10 (!!) before it looks properly.
- * I've tried this with a few other games (including R-Types) and so far, this
- * has not backfired.
- * */
+/*
+ * >= 10 for Galerians
+ * <= 18 for "Disney's Treasure Planet"
+ */
 #define MDEC_BIAS 10
 
 #define DSIZE			8
@@ -487,7 +485,7 @@ void psxDma0(u32 adr, u32 bcr, u32 chcr) {
 	size = (bcr >> 16) * (bcr & 0xffff);
 
 	switch (cmd >> 28) {
-		case 0x3: // decode
+		case 0x3: // decode 15/24bpp
 			mdec.rl = (u16 *) PSXM(adr);
 			/* now the mdec is busy till all data are decoded */
 			mdec.reg1 |= MDEC1_BUSY;
@@ -495,10 +493,8 @@ void psxDma0(u32 adr, u32 bcr, u32 chcr) {
 			mdec.rl_end = mdec.rl + (size * 2);
 
 			/* sanity check */
-			if(mdec.rl_end <= mdec.rl) {
-				MDECINDMA_INT( size / 4 );
-				return;
-			}
+			if(mdec.rl_end <= mdec.rl)
+				break;
 
 			/* process the pending dma1 */
 			if(mdec.pending_dma1.adr){
@@ -517,23 +513,18 @@ void psxDma0(u32 adr, u32 bcr, u32 chcr) {
 				iqtab_init(iq_y, p);
 				iqtab_init(iq_uv, p + 64);
 			}
-
-			MDECINDMA_INT( size / 4 );
-      return;
+			break;
 
 		case 0x6: // cosine table
 			// printf("mdec cosine table\n");
-
-			MDECINDMA_INT( size / 4 );
-      return;
+			break;
 
 		default:
 			// printf("mdec unknown command\n");
 			break;
 	}
 
-	HW_DMA0_CHCR &= SWAP32(~0x01000000);
-	DMA_INTERRUPT(0);
+	MDECINDMA_INT(size);
 }
 
 void mdec0Interrupt()
@@ -629,8 +620,10 @@ void psxDma1(u32 adr, u32 bcr, u32 chcr) {
 		}
 	}
 	
-	/* define the power of mdec */
-	MDECOUTDMA_INT(words * MDEC_BIAS);
+		/* define the power of mdec */
+		MDECOUTDMA_INT(words * MDEC_BIAS);
+		/* some CPU stalling */
+		psxRegs.cycle += words;
 	}
 }
 
diff --git a/libpcsxcore/psxdma.c b/libpcsxcore/psxdma.c
index c888ecdf..df02b00f 100644
--- a/libpcsxcore/psxdma.c
+++ b/libpcsxcore/psxdma.c
@@ -54,7 +54,7 @@ void psxDma4(u32 madr, u32 bcr, u32 chcr) { // SPU
 			words = (bcr >> 16) * (bcr & 0xffff);
 			SPU_writeDMAMem(ptr, words * 2, psxRegs.cycle);
 			HW_DMA4_MADR = SWAPu32(madr + words * 4);
-			SPUDMA_INT(words / 2);
+			SPUDMA_INT(words * 4);
 			return;
 
 		case 0x01000200: //spu to cpu transfer
@@ -73,7 +73,7 @@ void psxDma4(u32 madr, u32 bcr, u32 chcr) { // SPU
 			psxCpu->Clear(madr, words);
 
 			HW_DMA4_MADR = SWAPu32(madr + words * 4);
-			SPUDMA_INT(words / 2);
+			SPUDMA_INT(words * 4);
 			return;
 
 #ifdef PSXDMA_LOG
-- 
2.39.5