From 215c507634d288a438e2335e4912568452067da7 Mon Sep 17 00:00:00 2001
From: OBattler <oubattler@gmail.com>
Date: Mon, 8 Jan 2024 02:35:03 +0100
Subject: [PATCH] Soft reset on IDE device 1 causes the assertion of PDIAG-
 which causes the error register of device 0 to also be set to 1, indicating
 diagnostics passed successfully (+ a PIIX3 fix), fixes #4002.

---
 src/chipset/intel_piix.c | 6 ++++++
 src/disk/hdc_ide.c       | 6 +++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/chipset/intel_piix.c b/src/chipset/intel_piix.c
index 70035f6df..49d720d8b 100644
--- a/src/chipset/intel_piix.c
+++ b/src/chipset/intel_piix.c
@@ -597,6 +597,12 @@ piix_write(int func, int addr, uint8_t val, void *priv)
                         pci_set_mirq_routing(PCI_MIRQ0 + (addr & 0x01), PCI_IRQ_DISABLED);
                     else
                         pci_set_mirq_routing(PCI_MIRQ0 + (addr & 0x01), val & 0xf);
+                    if (dev->type == 3) {
+                        if (val & 0x20)
+                            sff_set_irq_mode(dev->bm[1], IRQ_MODE_MIRQ_0);
+                        else
+                            sff_set_irq_mode(dev->bm[1], IRQ_MODE_LEGACY);
+                    }
                     piix_log("MIRQ%i is %s\n", addr & 0x01, (val & 0x20) ? "disabled" : "enabled");
                 }
                 break;
diff --git a/src/disk/hdc_ide.c b/src/disk/hdc_ide.c
index 522f1ee66..4041b9ff6 100644
--- a/src/disk/hdc_ide.c
+++ b/src/disk/hdc_ide.c
@@ -1397,6 +1397,7 @@ ide_write_devctl(UNUSED(uint16_t addr), uint8_t val, void *priv)
             } else
                 ide->tf->atastat = DRDY_STAT | DSC_STAT;
             ide->tf->error   = 1;
+            ide_other->tf->error   = 1;    /* Assert PDIAG-. */
             dev->cur_dev &= ~1;
             ch = dev->cur_dev;
 
@@ -1410,7 +1411,8 @@ ide_write_devctl(UNUSED(uint16_t addr), uint8_t val, void *priv)
 
     old         = dev->devctl;
     dev->devctl = val;
-    if (!(val & 0x02) && (old & 0x02))
+    // if (!(val & 0x02) && (old & 0x02))
+    if ((old ^ val) & 0x02)
         ide_irq_update(ide_boards[ide->board], 1);
 }
 
@@ -1566,6 +1568,7 @@ ide_writeb(uint16_t addr, uint8_t val, void *priv)
             if ((ide->type == IDE_NONE) || ((ide->type & IDE_SHADOW) && (val != WIN_DRIVE_DIAGNOSTICS)))
                 break;
 
+            pclog("IRQ lower\n");
             ide_irq_lower(ide);
             ide->command = val;
 
@@ -2459,6 +2462,7 @@ ide_callback(void *priv)
             else {
                 ide->blocksize     = ide->tf->secount;
                 ide->tf->atastat   = DRDY_STAT | DSC_STAT;
+                pclog("IRQ raise\n");
                 ide_irq_raise(ide);
             }
             break;