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Pad: Only buffer a single byte

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Fixes Croc 2 memory card access freezing.
This commit is contained in:
Connor McLaughlin 2019-11-12 01:13:08 +10:00
parent d8452d7d7d
commit 6a82333d8f
2 changed files with 48 additions and 44 deletions
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72
src/core/pad.cpp
View file

@ -87,8 +87,10 @@ bool Pad::DoState(StateWrapper& sw)
sw.Do(&m_JOY_STAT.bits);
sw.Do(&m_JOY_MODE.bits);
sw.Do(&m_JOY_BAUD);
sw.Do(&m_RX_FIFO);
sw.Do(&m_TX_FIFO);
sw.Do(&m_receive_buffer);
sw.Do(&m_transmit_buffer);
sw.Do(&m_receive_buffer_full);
sw.Do(&m_transmit_buffer_full);
return !sw.HasError();
}
@ -98,16 +100,16 @@ u32 Pad::ReadRegister(u32 offset)
{
case 0x00: // JOY_DATA
{
if (m_RX_FIFO.IsEmpty())
{
if (!m_transmit_buffer_full)
Log_DevPrintf("Read from RX fifo when empty");
return 0;
}
const u8 value = m_RX_FIFO.Pop();
const u8 value = m_receive_buffer;
m_receive_buffer_full = false;
UpdateJoyStat();
Log_DebugPrintf("JOY_DATA (R) -> 0x%02X", ZeroExtend32(value));
return ZeroExtend32(value);
return (ZeroExtend32(value) | (ZeroExtend32(value) << 8) | (ZeroExtend32(value) << 16) |
(ZeroExtend32(value) << 24));
}
case 0x04: // JOY_STAT
@ -139,13 +141,12 @@ void Pad::WriteRegister(u32 offset, u32 value)
case 0x00: // JOY_DATA
{
Log_DebugPrintf("JOY_DATA (W) <- 0x%02X", value);
if (m_TX_FIFO.IsFull())
{
Log_WarningPrint("TX FIFO overrun");
m_TX_FIFO.RemoveOne();
}
m_TX_FIFO.Push(Truncate8(value));
if (m_transmit_buffer_full)
Log_WarningPrint("TX FIFO overrun");
m_transmit_buffer = Truncate8(value);
m_transmit_buffer_full = true;
if (!IsTransmitting() && CanTransfer())
BeginTransfer();
@ -182,6 +183,7 @@ void Pad::WriteRegister(u32 offset, u32 value)
BeginTransfer();
}
UpdateJoyStat();
return;
}
@ -232,17 +234,19 @@ void Pad::SoftReset()
m_JOY_CTRL.bits = 0;
m_JOY_STAT.bits = 0;
m_JOY_MODE.bits = 0;
m_RX_FIFO.Clear();
m_TX_FIFO.Clear();
m_receive_buffer = 0;
m_receive_buffer_full = false;
m_transmit_buffer = 0;
m_transmit_buffer_full = false;
ResetDeviceTransferState();
UpdateJoyStat();
}
void Pad::UpdateJoyStat()
{
m_JOY_STAT.RXFIFONEMPTY = !m_RX_FIFO.IsEmpty();
m_JOY_STAT.TXDONE = m_TX_FIFO.IsEmpty();
m_JOY_STAT.TXRDY = !m_TX_FIFO.IsFull();
m_JOY_STAT.RXFIFONEMPTY = m_receive_buffer_full;
m_JOY_STAT.TXDONE = !m_transmit_buffer_full && m_state == State::Idle;
m_JOY_STAT.TXRDY = !m_transmit_buffer_full;
}
void Pad::BeginTransfer()
@ -251,6 +255,8 @@ void Pad::BeginTransfer()
Log_DebugPrintf("Starting transfer");
m_JOY_CTRL.RXEN = true;
m_transmit_value = m_transmit_buffer;
m_transmit_buffer_full = false;
// The transfer or the interrupt must be delayed, otherwise the BIOS thinks there's no device detected.
// It seems to do something resembling the following:
@ -283,7 +289,8 @@ void Pad::DoTransfer()
// set rx?
m_JOY_CTRL.RXEN = true;
const u8 data_out = m_TX_FIFO.Pop();
const u8 data_out = m_transmit_value;
u8 data_in = 0xFF;
bool ack = false;
@ -296,19 +303,19 @@ void Pad::DoTransfer()
if (!memory_card || (ack = memory_card->Transfer(data_out, &data_in)) == false)
{
// nothing connected to this port
Log_DebugPrintf("Nothing connected or ACK'ed");
Log_TracePrintf("Nothing connected or ACK'ed");
}
else
{
// memory card responded, make it the active device until non-ack
Log_DebugPrintf("Transfer to memory card, data_out=0x%02X, data_in=0x%02X", data_in, data_out);
Log_TracePrintf("Transfer to memory card, data_out=0x%02X, data_in=0x%02X", data_out, data_in);
m_active_device = ActiveDevice::MemoryCard;
}
}
else
{
// controller responded, make it the active device until non-ack
Log_DebugPrintf("Transfer to controller, data_out=0x%02X, data_in=0x%02X", data_in, data_out);
Log_TracePrintf("Transfer to controller, data_out=0x%02X, data_in=0x%02X", data_out, data_in);
m_active_device = ActiveDevice::Controller;
}
}
@ -317,19 +324,26 @@ void Pad::DoTransfer()
case ActiveDevice::Controller:
{
if (controller)
{
ack = controller->Transfer(data_out, &data_in);
Log_TracePrintf("Transfer to controller, data_out=0x%02X, data_in=0x%02X", data_out, data_in);
}
}
break;
case ActiveDevice::MemoryCard:
{
if (memory_card)
{
ack = memory_card->Transfer(data_out, &data_in);
Log_TracePrintf("Transfer to memory card, data_out=0x%02X, data_in=0x%02X", data_out, data_in);
}
}
break;
}
m_RX_FIFO.Push(data_in);
m_receive_buffer = data_in;
m_receive_buffer_full = true;
m_JOY_STAT.ACKINPUT |= ack;
// device no longer active?
@ -343,17 +357,7 @@ void Pad::DoTransfer()
m_interrupt_controller->InterruptRequest(InterruptController::IRQ::IRQ7);
}
if (m_TX_FIFO.IsEmpty())
{
EndTransfer();
}
else
{
// queue the next byte
m_ticks_remaining += GetTransferTicks();
m_system->SetDowncount(m_ticks_remaining);
}
UpdateJoyStat();
}

18
src/core/pad.h
View file

@ -89,10 +89,7 @@ private:
};
bool IsTransmitting() const { return m_state == State::Transmitting; }
bool CanTransfer() const
{
return !m_TX_FIFO.IsEmpty() && !m_RX_FIFO.IsFull() && m_JOY_CTRL.SELECT && m_JOY_CTRL.TXEN;
}
bool CanTransfer() const { return m_transmit_buffer_full && m_JOY_CTRL.SELECT && m_JOY_CTRL.TXEN; }
TickCount GetTransferTicks() const { return static_cast<TickCount>(ZeroExtend32(m_JOY_BAUD) * 8); }
@ -106,6 +103,9 @@ private:
System* m_system = nullptr;
InterruptController* m_interrupt_controller = nullptr;
std::array<std::shared_ptr<PadDevice>, NUM_SLOTS> m_controllers;
std::array<std::shared_ptr<MemoryCard>, NUM_SLOTS> m_memory_cards;
State m_state = State::Idle;
TickCount m_ticks_remaining = 0;
@ -115,9 +115,9 @@ private:
u16 m_JOY_BAUD = 0;
ActiveDevice m_active_device = ActiveDevice::None;
InlineFIFOQueue<u8, 8> m_RX_FIFO;
InlineFIFOQueue<u8, 2> m_TX_FIFO;
std::array<std::shared_ptr<PadDevice>, NUM_SLOTS> m_controllers;
std::array<std::shared_ptr<MemoryCard>, NUM_SLOTS> m_memory_cards;
u8 m_receive_buffer = 0;
u8 m_transmit_buffer = 0;
u8 m_transmit_value = 0;
bool m_receive_buffer_full = false;
bool m_transmit_buffer_full = false;
};