From 363869f8a340ef2c11e725a70e2b803585b30cb9 Mon Sep 17 00:00:00 2001
From: Rix <rix@nobis-crew.org>
Date: Sat, 10 Oct 2026 08:59:18 -0700
Subject: [PATCH] tests: GPUSTAT.24 survives a save state

Raises IRQ1 from code poked into RAM, saves, acks with GP1(02h), loads, and checks the flag is back. Fails with the restore in GPU::deserialize removed.
---
 tests/pcsxrunner/gpu-irq.cc | 50 +++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/tests/pcsxrunner/gpu-irq.cc b/tests/pcsxrunner/gpu-irq.cc
index 18836417..65081afa 100644
--- a/tests/pcsxrunner/gpu-irq.cc
+++ b/tests/pcsxrunner/gpu-irq.cc
@@ -28,3 +28,53 @@ TEST(GPUIRQ, RequestAcknowledge) {
     int ret = invoker.invoke();
     EXPECT_EQ(ret, 0);
 }
+
+// IRQ1 survives a save state. Code poked into RAM raises it with GP0(1Fh) and keeps copying
+// GPUSTAT to 0x80100100; a state is saved, GP1(02h) acks the flag, the state is loaded, and
+// GPUSTAT.24 must be set again. Loading replays GP1 writes that clear the flag before
+// GPU::deserialize puts it back.
+static const char c_irq1SaveState[] = R"(
+local ram = ffi.cast('uint32_t*', PCSX.getMemPtr())
+local base = 0x100000 / 4
+local out = 0x100100 / 4
+local stubs = {
+    -- 0x80100000: GP0(1Fh) raises IRQ1, then GPUSTAT -> 0x80100100 forever
+    0x3c081f80, 0x3c091f00, 0xad091810, 0x3c0b8010,
+    0x8d0a1814, 0x00000000, 0xad6a0100, 0x08040004, 0x00000000,
+    0, 0, 0, 0, 0, 0, 0,
+    -- 0x80100040: GP1(02h) acks IRQ1, then the same loop
+    0x3c081f80, 0x3c090200, 0xad091814, 0x3c0b8010,
+    0x8d0a1814, 0x00000000, 0xad6a0100, 0x08040014, 0x00000000,
+}
+local sentinel = 0xdeadbeef
+local frames = 0
+local state
+local function irq1() return bit.band(ram[out], 0x01000000) ~= 0 and ram[out] ~= sentinel end
+IRQ1SaveStateListener = PCSX.Events.createEventListener('GPU::Vsync', function()
+    frames = frames + 1
+    if frames == 120 then
+        for i, w in ipairs(stubs) do ram[base + i - 1] = w end
+        ram[out] = sentinel
+        PCSX.getRegisters().pc = 0x80100000
+    elseif frames == 122 then
+        if not irq1() then print('IRQ1 never raised') PCSX.quit(2) return end
+        state = PCSX.createSaveState()
+        ram[out] = sentinel
+        PCSX.getRegisters().pc = 0x80100040
+    elseif frames == 124 then
+        if ram[out] == sentinel or irq1() then print('GP1(02h) did not ack IRQ1') PCSX.quit(3) return end
+        PCSX.loadSaveState(state)
+    elseif frames == 125 then
+        ram[out] = sentinel
+    elseif frames == 127 then
+        if irq1() then PCSX.quit(0) else print('IRQ1 lost across the save state') PCSX.quit(1) end
+    end
+end)
+)";
+
+TEST(GPUIRQ, SaveStateKeepsFlag) {
+    MainInvoker invoker("-no-ui", "-run", "-bios", "src/mips/openbios/openbios.bin", "-testmode", "-interpreter",
+                        "-exec", c_irq1SaveState);
+    int ret = invoker.invoke();
+    EXPECT_EQ(ret, 0);
+}