From 0aa695c070174998af70a7b20dabb494252e55d1 Mon Sep 17 00:00:00 2001
From: OBattler <oubattler@gmail.com>
Date: Thu, 25 Apr 2024 10:55:07 +0200
Subject: [PATCH] Matrox FIFO status fix.

---
 src/video/vid_mga.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/src/video/vid_mga.c b/src/video/vid_mga.c
index aec571356..fdbb2e411 100644
--- a/src/video/vid_mga.c
+++ b/src/video/vid_mga.c
@@ -1562,14 +1562,14 @@ mystique_ctrl_read_b(uint32_t addr, void *priv)
         switch (addr & 0x3fff) {
             case REG_FIFOSTATUS:
                 fifocount = FIFO_SIZE - FIFO_ENTRIES;
-                if (fifocount > 64)
-                    fifocount = 64;
+                if (fifocount > (mystique->type <= MGA_1064SG ? 32 : 64))
+                    fifocount = (mystique->type <= MGA_1064SG ? 32 : 64);
                 ret = fifocount;
                 break;
             case REG_FIFOSTATUS + 1:
                 if (FIFO_EMPTY)
                     ret |= 2;
-                else if (FIFO_ENTRIES >= 64)
+                else if (FIFO_ENTRIES >= (mystique->type <= MGA_1064SG ? 32 : 64))
                     ret |= 1;
                 break;
             case REG_FIFOSTATUS + 2:
@@ -1583,6 +1583,10 @@ mystique_ctrl_read_b(uint32_t addr, void *priv)
                     ret |= REG_STATUS_VSYNCSTS;
                 if (ret & 1)
                     mystique->softrap_status_read = 1;
+                if (mystique->softrap_status_read == 0 && !(ret & 1)) {
+                    mystique->softrap_status_read = 1;
+                    ret |= 1;
+                }
                 break;
             case REG_STATUS + 1:
                 ret = (mystique->status >> 8) & 0xff;