From 3133687e6820d98581855010ae772473666d2643 Mon Sep 17 00:00:00 2001
From: Lior Halphon <LIJI32@gmail.com>
Date: Sun, 16 Jan 2022 00:50:08 +0200
Subject: [PATCH] Potential logic bug fixes

---
 Core/display.c | 1 +
 Core/memory.c  | 6 +++++-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/Core/display.c b/Core/display.c
index de84999..1b90ddb 100644
--- a/Core/display.c
+++ b/Core/display.c
@@ -1613,6 +1613,7 @@ void GB_display_run(GB_gameboy_t *gb, unsigned cycles, bool force)
                     
                     if (unlikely(GB_is_dma_active(gb))) {
                         unsigned offset = cycles - gb->display_cycles; // Time passed in 8MHz ticks
+                        cycles = gb->display_cycles;
                         if (offset) {
                             if (!gb->cgb_double_speed) {
                                 offset >>= 1; // Convert to T-cycles
diff --git a/Core/memory.c b/Core/memory.c
index 8409490..572eae3 100644
--- a/Core/memory.c
+++ b/Core/memory.c
@@ -292,7 +292,11 @@ static uint8_t read_mbc_rom(GB_gameboy_t *gb, uint16_t addr)
 
 static uint8_t read_vram(GB_gameboy_t *gb, uint16_t addr)
 {
-    GB_display_sync(gb);
+    if (!GB_is_dma_active(gb)) {
+        /* Prevent syncing from a DMA read. Batching doesn't happen during DMA anyway. */
+        GB_display_sync(gb);
+    }
+    
     if (unlikely(gb->vram_read_blocked)) {
         return 0xFF;
     }