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Merged
dingusdev merged 2 commits into from
Aug 12, 2026
+43 −30
Merged

ati: Correct VBL status and interrupt handling #208

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d5c45cb
ati: Fix VBLANK status field updates
mihaip Aug 10, 2026
1cc1fde
ati: Latch enabled display interrupts until acknowledged
mihaip Aug 10, 2026
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37 changes: 20 additions & 17 deletions devices/video/atimach64gx.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -525,6 +525,7 @@ void AtiMach64Gx::write_reg(uint32_t reg_offset, uint32_t value, uint32_t size)

new_value = (old_value & bits_read_only) | (new_value & ~bits_read_only);
WRITE_VALUE_AND_LOG(ATIINTERRUPT);
this->update_interrupt();
return;
}
case ATI_CRTC_GEN_CNTL:
Expand Down Expand Up @@ -904,7 +905,7 @@ void AtiMach64Gx::get_cursor_position(int& x, int& y) {
int AtiMach64Gx::device_postinit()
{
this->vbl_cb = [this](uint8_t irq_line_state) {
insert_bits<uint32_t>(this->regs[ATI_CRTC_INT_CNTL], irq_line_state, ATI_CRTC_VBLANK, irq_line_state);
insert_bits<uint32_t>(this->regs[ATI_CRTC_INT_CNTL], irq_line_state, ATI_CRTC_VBLANK, 1);
if (irq_line_state) {
set_bit(this->regs[ATI_CRTC_INT_CNTL], ATI_CRTC_VBLANK_INT);
set_bit(this->regs[ATI_CRTC_INT_CNTL], ATI_CRTC_VLINE_INT);
Expand All @@ -914,26 +915,28 @@ int AtiMach64Gx::device_postinit()
#endif
}

bool do_interrupt =
bit_set(this->regs[ATI_CRTC_INT_CNTL], ATI_CRTC_VBLANK_INT_EN) ||
bit_set(this->regs[ATI_CRTC_INT_CNTL], ATI_CRTC_VLINE_INT_EN) ||
#if 1
#else
bit_set(this->regs[ATI_CRTC_GEN_CNTL], ATI_CRTC_VSYNC_INT_EN) ||
#endif
0;

LOG_F(ATIINTERRUPT, "%s: irq_line_state:%d do_interrupt:%d CRTC_INT_CNTL:%08x",
this->name.c_str(), irq_line_state, do_interrupt,
this->regs[ATI_CRTC_INT_CNTL]);

if (do_interrupt) {
this->pci_interrupt(irq_line_state);
}
this->update_interrupt();
};
return 0;
}

void AtiMach64Gx::update_interrupt()
{
uint32_t int_cntl = this->regs[ATI_CRTC_INT_CNTL];
bool new_pci_irq_line_state =
(bit_set(int_cntl, ATI_CRTC_VBLANK_INT_EN) &&
bit_set(int_cntl, ATI_CRTC_VBLANK_INT)) ||
(bit_set(int_cntl, ATI_CRTC_VLINE_INT_EN) &&
bit_set(int_cntl, ATI_CRTC_VLINE_INT));

if (new_pci_irq_line_state != this->pci_irq_line_state) {
this->pci_irq_line_state = new_pci_irq_line_state;
LOG_F(ATIINTERRUPT, "%s: pci_irq_line_state:%d CRTC_INT_CNTL:%08x",
this->name.c_str(), this->pci_irq_line_state, int_cntl);
this->pci_interrupt(this->pci_irq_line_state);
}
}

// ========================== IBM RGB514 related code ==========================
const char* AtiMach64Gx::rgb514_get_reg_name(uint32_t reg_addr)
{
Expand Down
2 changes: 2 additions & 0 deletions devices/video/atimach64gx.h
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Original file line number Diff line number Diff line change
Expand Up @@ -76,8 +76,10 @@ class AtiMach64Gx : public PCIDevice, public VideoCtrlBase {

private:
void change_one_bar(uint32_t &aperture, uint32_t aperture_size, uint32_t aperture_new, int bar_num);
void update_interrupt();

uint32_t regs[256] = {}; // internal registers
bool pci_irq_line_state = false;

int vram_size;

Expand Down
32 changes: 19 additions & 13 deletions devices/video/atirage.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -658,6 +658,8 @@ void ATIRage::write_reg(uint32_t reg_offset, uint32_t value, uint32_t size) {
}

WRITE_VALUE_AND_LOG(9);
if (reg_num == ATI_CRTC_INT_CNTL)
this->update_interrupt();
}

bool ATIRage::io_access_allowed(uint32_t offset) {
Expand Down Expand Up @@ -1033,7 +1035,7 @@ void ATIRage::get_cursor_position(int& x, int& y) {
int ATIRage::device_postinit()
{
this->vbl_cb = [this](uint8_t irq_line_state) {
insert_bits<uint32_t>(this->regs[ATI_CRTC_INT_CNTL], irq_line_state, ATI_CRTC_VBLANK, irq_line_state);
insert_bits<uint32_t>(this->regs[ATI_CRTC_INT_CNTL], irq_line_state, ATI_CRTC_VBLANK, 1);
if (irq_line_state) {
set_bit(this->regs[ATI_CRTC_INT_CNTL], ATI_CRTC_VBLANK_INT);
set_bit(this->regs[ATI_CRTC_INT_CNTL], ATI_CRTC_VLINE_INT);
Expand All @@ -1043,22 +1045,26 @@ int ATIRage::device_postinit()
#endif
}

bool do_interrupt =
bit_set(this->regs[ATI_CRTC_INT_CNTL], ATI_CRTC_VBLANK_INT_EN) ||
bit_set(this->regs[ATI_CRTC_INT_CNTL], ATI_CRTC_VLINE_INT_EN) ||
#if 1
#else
bit_set(this->regs[ATI_CRTC_GEN_CNTL], ATI_CRTC_VSYNC_INT_EN) ||
#endif
0;

if (do_interrupt) {
this->pci_interrupt(irq_line_state);
}
this->update_interrupt();
};
return 0;
}

void ATIRage::update_interrupt()
{
uint32_t int_cntl = this->regs[ATI_CRTC_INT_CNTL];
bool new_pci_irq_line_state =
(bit_set(int_cntl, ATI_CRTC_VBLANK_INT_EN) &&
bit_set(int_cntl, ATI_CRTC_VBLANK_INT)) ||
(bit_set(int_cntl, ATI_CRTC_VLINE_INT_EN) &&
bit_set(int_cntl, ATI_CRTC_VLINE_INT));

if (new_pci_irq_line_state != this->pci_irq_line_state) {
this->pci_irq_line_state = new_pci_irq_line_state;
this->pci_interrupt(this->pci_irq_line_state);
}
}

// =================================== Draw Engine =====================================
void ATIRage::begin_drawing(uint32_t initiator, uint32_t value) {
switch(initiator) {
Expand Down
2 changes: 2 additions & 0 deletions devices/video/atirage.h
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Original file line number Diff line number Diff line change
Expand Up @@ -89,6 +89,7 @@ class ATIRage : public PCIDevice, public VideoCtrlBase {
private:
void change_one_bar(uint32_t &aperture, uint32_t aperture_size,
uint32_t aperture_new, int bar_num);
void update_interrupt();

void begin_drawing(uint32_t initiator, uint32_t value);
void draw_rect(uint32_t width, uint32_t height);
Expand All @@ -102,6 +103,7 @@ class ATIRage : public PCIDevice, public VideoCtrlBase {
uint8_t plls[64] = {}; // internal PLL registers

uint8_t cmd_fifo_size = 0;
bool pci_irq_line_state = false;

bool host_data_active = false;
uint32_t host_dst_width = 0;
Expand Down
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