From cf06497456cf576d8c68de67cf039a07160e0e49 Mon Sep 17 00:00:00 2001
From: Vicki Pfau <vi@endrift.com>
Date: Fri, 18 Feb 2022 20:31:05 -0800
Subject: [PATCH] GBA DMA: Enhanced logging (closes #2454)

---
 CHANGES                         |  1 +
 include/mgba/internal/gba/dma.h |  4 ++++
 src/gba/dma.c                   | 20 ++++++++++++++------
 3 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/CHANGES b/CHANGES
index 846ab2a3c..a76c5c7af 100644
--- a/CHANGES
+++ b/CHANGES
@@ -44,6 +44,7 @@ Misc:
  - Core: Suspend runloop when a core crashes
  - GB Video: Add default SGB border
  - GBA: Automatically skip BIOS if ROM has invalid logo
+ - GBA DMA: Enhanced logging (closes mgba.io/i/2454)
  - mGUI: Add margin to right-aligned menu text (fixes mgba.io/i/871)
  - Qt: Rearrange menus some
  - Qt: Clean up cheats dialog
diff --git a/include/mgba/internal/gba/dma.h b/include/mgba/internal/gba/dma.h
index 6f880c971..192b3995a 100644
--- a/include/mgba/internal/gba/dma.h
+++ b/include/mgba/internal/gba/dma.h
@@ -10,6 +10,8 @@
 
 CXX_GUARD_START
 
+#include <mgba/core/log.h>
+
 enum GBADMAControl {
 	GBA_DMA_INCREMENT = 0,
 	GBA_DMA_DECREMENT = 1,
@@ -34,6 +36,8 @@ DECL_BITS(GBADMARegister, Timing, 12, 2);
 DECL_BIT(GBADMARegister, DoIRQ, 14);
 DECL_BIT(GBADMARegister, Enable, 15);
 
+mLOG_DECLARE_CATEGORY(GBA_DMA);
+
 struct GBADMA {
 	GBADMARegister reg;
 
diff --git a/src/gba/dma.c b/src/gba/dma.c
index 5807e506f..759140da6 100644
--- a/src/gba/dma.c
+++ b/src/gba/dma.c
@@ -8,6 +8,8 @@
 #include <mgba/internal/gba/gba.h>
 #include <mgba/internal/gba/io.h>
 
+mLOG_DEFINE_CATEGORY(GBA_DMA, "GBA DMA", "gba.dma");
+
 static void _dmaEvent(struct mTiming* timing, void* context, uint32_t cyclesLate);
 
 static void GBADMAService(struct GBA* gba, int number, struct GBADMA* info);
@@ -43,10 +45,10 @@ static bool _isValidDMADAD(int dma, uint32_t address) {
 
 uint32_t GBADMAWriteSAD(struct GBA* gba, int dma, uint32_t address) {
 	struct GBAMemory* memory = &gba->memory;
-	address &= 0x0FFFFFFE;
 	if (_isValidDMASAD(dma, address)) {
-		memory->dma[dma].source = address;
+		memory->dma[dma].source = address & 0x0FFFFFFE;
 	} else {
+		mLOG(GBA_DMA, GAME_ERROR, "Invalid DMA source address: 0x%08X", address);
 		memory->dma[dma].source = 0;
 	}
 	return memory->dma[dma].source;
@@ -57,6 +59,8 @@ uint32_t GBADMAWriteDAD(struct GBA* gba, int dma, uint32_t address) {
 	address &= 0x0FFFFFFE;
 	if (_isValidDMADAD(dma, address)) {
 		memory->dma[dma].dest = address;
+	} else {
+		mLOG(GBA_DMA, GAME_ERROR, "Invalid DMA destination address: 0x%08X", address);
 	}
 	return memory->dma[dma].dest;
 }
@@ -78,7 +82,7 @@ uint16_t GBADMAWriteCNT_HI(struct GBA* gba, int dma, uint16_t control) {
 	currentDma->reg = control;
 
 	if (GBADMARegisterIsDRQ(currentDma->reg)) {
-		mLOG(GBA_MEM, STUB, "DRQ not implemented");
+		mLOG(GBA_DMA, STUB, "DRQ not implemented");
 	}
 
 	if (!wasEnabled && GBADMARegisterIsEnable(currentDma->reg)) {
@@ -87,11 +91,15 @@ uint16_t GBADMAWriteCNT_HI(struct GBA* gba, int dma, uint16_t control) {
 
 		uint32_t width = 2 << GBADMARegisterGetWidth(currentDma->reg);
 		if (currentDma->nextSource & (width - 1)) {
-			mLOG(GBA_MEM, GAME_ERROR, "Misaligned DMA source address: 0x%08X", currentDma->nextSource);
+			mLOG(GBA_DMA, GAME_ERROR, "Misaligned DMA source address: 0x%08X", currentDma->nextSource);
 		}
 		if (currentDma->nextDest & (width - 1)) {
-			mLOG(GBA_MEM, GAME_ERROR, "Misaligned DMA destination address: 0x%08X", currentDma->nextDest);
+			mLOG(GBA_DMA, GAME_ERROR, "Misaligned DMA destination address: 0x%08X", currentDma->nextDest);
 		}
+		mLOG(GBA_DMA, INFO, "Starting DMA %i 0x%08X -> 0x%08X (%04X:%04X)", dma,
+		     currentDma->nextSource, currentDma->nextDest,
+		     currentDma->reg, currentDma->count & 0xFFFF);
+
 		currentDma->nextSource &= -width;
 		currentDma->nextDest &= -width;
 
@@ -114,7 +122,7 @@ void GBADMASchedule(struct GBA* gba, int number, struct GBADMA* info) {
 	case GBA_DMA_TIMING_CUSTOM:
 		switch (number) {
 		case 0:
-			mLOG(GBA_MEM, WARN, "Discarding invalid DMA0 scheduling");
+			mLOG(GBA_DMA, WARN, "Discarding invalid DMA0 scheduling");
 			return;
 		case 1:
 		case 2: