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Changed the way the PIC keyboard and mouse IRQ latches operate to avoid spurious IRQ's.

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This commit is contained in:
OBattler
2023-05-16 00:38:28 +02:00
parent 5c6255f787
commit 1863b72f67
1 changed files with 16 additions and 4 deletions
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20
src/pic.c
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@@ -57,6 +57,8 @@ static int shadow = 0, elcr_enabled = 0,
static uint16_t smi_irq_mask = 0x0000,
smi_irq_status = 0x0000;
static uint16_t latched_irqs = 0x0000;
static void (*update_pending)(void);
#ifdef ENABLE_PIC_LOG
@@ -397,10 +399,10 @@ pic_latch_read(uint16_t addr, void *priv)
pic_log("pic_latch_read(%i, %i): %02X%02X\n", kbd_latch, mouse_latch, pic2.lines & 0x10, pic.lines & 0x02);
if (kbd_latch && (pic.lines & 0x02))
if (kbd_latch && (latched_irqs & 0x0002))
picintc(0x0002);
if (mouse_latch && (pic2.lines & 0x10))
if (mouse_latch && (latched_irqs & 0x1000))
picintc(0x1000);
/* Return FF - we just lower IRQ 1 and IRQ 12. */
@@ -572,6 +574,7 @@ pic_reset_hard(void)
/* Explicitly reset the latches. */
kbd_latch = mouse_latch = 0;
latched_irqs = 0x0000;
/* The situation is as follows: There is a giant mess when it comes to these latches on real hardware,
to the point that there's even boards with board-level latched that get used in place of the latches
@@ -656,7 +659,7 @@ picint_common(uint16_t num, int level, int set)
/* Latch IRQ 12 if the mouse latch is enabled. */
if ((num & 0x1000) && mouse_latch)
pic2.lines |= 0x10;
latched_irqs |= 0x1000;
pic2.irr |= (num >> 8);
}
@@ -665,8 +668,9 @@ picint_common(uint16_t num, int level, int set)
if (level)
pic.lines |= (num & 0x00ff);
/* Latch IRQ 1 if the keyboard latch is enabled. */
if (kbd_latch && (num & 0x0002))
pic.lines |= 0x02;
latched_irqs |= 0x0002;
pic.irr |= (num & 0x00ff);
}
@@ -676,12 +680,20 @@ picint_common(uint16_t num, int level, int set)
if (num & 0xff00) {
pic2.lines &= ~(num >> 8);
/* Unlatch IRQ 12 if the mouse latch is enabled. */
if ((num & 0x1000) && mouse_latch)
latched_irqs &= 0xefff;
pic2.irr &= ~(num >> 8);
}
if (num & 0x00ff) {
pic.lines &= ~(num & 0x00ff);
/* Unlatch IRQ 1 if the keyboard latch is enabled. */
if (kbd_latch && (num & 0x0002))
latched_irqs &= 0xfffd;
pic.irr &= ~(num & 0x00ff);
}
}