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DVDInterface: Add a delay for commands other than regular reads 

Behavior inspired by WII_IPC_HLE_Device_DI.
This commit is contained in:
JosJuice 2014-11-16 17:53:24 +01:00
parent c6e695b245
commit 091db36162
1 changed files with 109 additions and 99 deletions
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208
Source/Core/Core/HW/DVDInterface.cpp
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@ -268,7 +268,8 @@ void UpdateInterrupts();
void GenerateDIInterrupt(DI_InterruptType _DVDInterrupt);
void ExecuteCommand();
void FinishExecuteRead();
s64 CalculateDiscReadTime(u64 offset, s64 length);
u64 SimulateDiscReadTime();
s64 CalculateRawDiscReadTime(u64 offset, s64 length);
void DoState(PointerWrap &p)
{
@ -301,7 +302,12 @@ void DoState(PointerWrap &p)
static void TransferComplete(u64 userdata, int cyclesLate)
{
if (m_DICR.TSTART)
FinishExecuteRead();
{
m_DICR.TSTART = 0;
m_DILENGTH.Length = 0;
GenerateDIInterrupt(INT_TCINT);
g_ErrorCode = 0;
}
}
static u32 ProcessDTKSamples(short *tempPCM, u32 num_samples)
@ -598,6 +604,11 @@ void GenerateDIInterrupt(DI_InterruptType _DVDInterrupt)
void ExecuteCommand()
{
// This variable is used to simulate the time is takes to execute a command.
// 1 / 15000 seconds is just some arbitrary default value.
// Commands that implement more precise timing are supposed to overwrite this.
u64 ticks_until_TC = SystemTimers::GetTicksPerSecond() / 15000;
// _dbg_assert_(DVDINTERFACE, _DICR.RW == 0); // only DVD to Memory
int GCAM = ((SConfig::GetInstance().m_SIDevice[0] == SIDEVICE_AM_BASEBOARD) &&
(SConfig::GetInstance().m_EXIDevice[2] == EXIDEVICE_AM_BASEBOARD))
@ -715,91 +726,13 @@ void ExecuteCommand()
}
}
u64 ticksUntilTC = 0;
ticks_until_TC = SimulateDiscReadTime();
// The drive buffers 1 MiB (?) of data after every read request;
// if a read request is covered by this buffer (or if it's
// faster to wait for the data to be buffered), the drive
// doesn't seek; it returns buffered data. Data can be
// transferred from the buffer at up to 16 MiB/s.
//
// If the drive has to seek, the time this takes varies a lot.
// A short seek is around 50 ms; a long seek is around 150 ms.
// However, the time isn't purely dependent on the distance; the
// pattern of previous seeks seems to matter in a way I'm
// not sure how to explain.
//
// Metroid Prime is a good example of a game that's sensitive to
// all of these details; if there isn't enough latency in the
// right places, doors open too quickly, and if there's too
// much latency in the wrong places, the video before the
// save-file select screen lags.
//
// For now, just use a very rough approximation: 50 ms seek
// for reads outside 1 MiB, accelerated reads within 1 MiB.
// We can refine this if someone comes up with a more complete
// model for seek times.
u64 cur_time = CoreTiming::GetTicks();
// Number of ticks it takes to seek and read directly from the disk.
u64 disk_read_duration = CalculateDiscReadTime(iDVDOffset, m_DILENGTH.Length) +
SystemTimers::GetTicksPerSecond() / 1000 * DISC_ACCESS_TIME_MS;
if (iDVDOffset + m_DILENGTH.Length - g_last_read_offset > 1024 * 1024)
// Here is the actual disc reading
if (!DVDRead(iDVDOffset, m_DIMAR.Address, m_DILENGTH.Length))
{
// No buffer; just use the simple seek time + read time.
DEBUG_LOG(DVDINTERFACE, "Seeking %" PRId64 " bytes", s64(g_last_read_offset) - s64(iDVDOffset));
ticksUntilTC = disk_read_duration;
g_last_read_time = cur_time + ticksUntilTC;
PanicAlertT("Can't read from DVD_Plugin - DVD-Interface: Fatal Error");
}
else
{
// Possibly buffered; use the buffer if it saves time.
// It's not proven that the buffer actually behaves like this, but
// it appears to be a decent approximation.
// Time at which the buffer will contain the data we need.
u64 buffer_fill_time = g_last_read_time +
CalculateDiscReadTime(g_last_read_offset, iDVDOffset + m_DILENGTH.Length - g_last_read_offset);
// Number of ticks it takes to transfer the data from the buffer to memory.
u64 buffer_read_duration = m_DILENGTH.Length *
(SystemTimers::GetTicksPerSecond() / BUFFER_TRANSFER_RATE);
if (cur_time > buffer_fill_time)
{
DEBUG_LOG(DVDINTERFACE, "Fast buffer read at %" PRId64, s64(iDVDOffset));
ticksUntilTC = buffer_read_duration;
g_last_read_time = buffer_fill_time;
}
else if (cur_time + disk_read_duration > buffer_fill_time)
{
DEBUG_LOG(DVDINTERFACE, "Slow buffer read at %" PRId64, s64(iDVDOffset));
ticksUntilTC = std::max(buffer_fill_time - cur_time, buffer_read_duration);
g_last_read_time = buffer_fill_time;
}
else
{
DEBUG_LOG(DVDINTERFACE, "Short seek %" PRId64 " bytes", s64(g_last_read_offset) - s64(iDVDOffset));
ticksUntilTC = disk_read_duration;
g_last_read_time = cur_time + ticksUntilTC;
}
}
g_last_read_offset = (iDVDOffset + m_DILENGTH.Length - 2048) & ~2047;
if (SConfig::GetInstance().m_LocalCoreStartupParameter.bFastDiscSpeed)
{
// Make sure fast disc speed performs "instant" reads; in addition
// to being used to speed up games, fast disc speed is used as a
// workaround for crashes in certain games, including Star Wars
// Rogue Leader.
FinishExecuteRead();
return;
}
CoreTiming::ScheduleEvent((int)ticksUntilTC, tc);
// Early return; we'll finish executing the command in FinishExecuteRead.
return;
}
break;
@ -1108,33 +1041,110 @@ void ExecuteCommand()
break;
}
// transfer is done
m_DICR.TSTART = 0;
m_DILENGTH.Length = 0;
GenerateDIInterrupt(INT_TCINT);
g_ErrorCode = 0;
// The transfer is finished after a delay
CoreTiming::ScheduleEvent((int)ticks_until_TC, tc);
}
void FinishExecuteRead()
// Simulates the timing aspects of reading data from a disc.
// Sets g_last_read_offset and g_last_read_time, and returns ticks_until_TC.
u64 SimulateDiscReadTime()
{
u32 iDVDOffset = m_DICMDBUF[1].Hex << 2;
u64 DVD_offset = (u64)m_DICMDBUF[1].Hex << 2;
u64 current_time = CoreTiming::GetTicks();
u64 ticks_until_TC;
if (!DVDRead(iDVDOffset, m_DIMAR.Address, m_DILENGTH.Length))
if (SConfig::GetInstance().m_LocalCoreStartupParameter.bFastDiscSpeed)
{
PanicAlertT("Can't read from DVD_Plugin - DVD-Interface: Fatal Error");
// Make sure fast disc speed performs "instant" reads; in addition
// to being used to speed up games, fast disc speed is used as a
// workaround for crashes in certain games, including Star Wars
// Rogue Leader.
ticks_until_TC = 0;
g_last_read_time = current_time;
}
else
{
// The drive buffers 1 MiB (?) of data after every read request;
// if a read request is covered by this buffer (or if it's
// faster to wait for the data to be buffered), the drive
// doesn't seek; it returns buffered data. Data can be
// transferred from the buffer at up to 16 MiB/s.
//
// If the drive has to seek, the time this takes varies a lot.
// A short seek is around 50 ms; a long seek is around 150 ms.
// However, the time isn't purely dependent on the distance; the
// pattern of previous seeks seems to matter in a way I'm
// not sure how to explain.
//
// Metroid Prime is a good example of a game that's sensitive to
// all of these details; if there isn't enough latency in the
// right places, doors open too quickly, and if there's too
// much latency in the wrong places, the video before the
// save-file select screen lags.
//
// For now, just use a very rough approximation: 50 ms seek
// for reads outside 1 MiB, accelerated reads within 1 MiB.
// We can refine this if someone comes up with a more complete
// model for seek times.
// Number of ticks it takes to seek and read directly from the disk.
u64 disk_read_duration = CalculateRawDiscReadTime(DVD_offset, m_DILENGTH.Length) +
SystemTimers::GetTicksPerSecond() / 1000 * DISC_ACCESS_TIME_MS;
if (DVD_offset + m_DILENGTH.Length - g_last_read_offset > 1024 * 1024)
{
// No buffer; just use the simple seek time + read time.
DEBUG_LOG(DVDINTERFACE, "Seeking %" PRId64 " bytes",
s64(g_last_read_offset) - s64(DVD_offset));
ticks_until_TC = disk_read_duration;
g_last_read_time = current_time + ticks_until_TC;
}
else
{
// Possibly buffered; use the buffer if it saves time.
// It's not proven that the buffer actually behaves like this, but
// it appears to be a decent approximation.
// Time at which the buffer will contain the data we need.
u64 buffer_fill_time = g_last_read_time +
CalculateRawDiscReadTime(g_last_read_offset,
DVD_offset + m_DILENGTH.Length - g_last_read_offset);
// Number of ticks it takes to transfer the data from the buffer to memory.
u64 buffer_read_duration = m_DILENGTH.Length *
(SystemTimers::GetTicksPerSecond() / BUFFER_TRANSFER_RATE);
if (current_time > buffer_fill_time)
{
DEBUG_LOG(DVDINTERFACE, "Fast buffer read at %" PRId64, s64(DVD_offset));
ticks_until_TC = buffer_read_duration;
g_last_read_time = buffer_fill_time;
}
else if (current_time + disk_read_duration > buffer_fill_time)
{
DEBUG_LOG(DVDINTERFACE, "Slow buffer read at %" PRId64, s64(DVD_offset));
ticks_until_TC = std::max(buffer_fill_time - current_time,
buffer_read_duration);
g_last_read_time = buffer_fill_time;
}
else
{
DEBUG_LOG(DVDINTERFACE, "Short seek %" PRId64 " bytes",
s64(g_last_read_offset) - s64(DVD_offset));
ticks_until_TC = disk_read_duration;
g_last_read_time = current_time + ticks_until_TC;
}
}
}
// transfer is done
m_DICR.TSTART = 0;
m_DILENGTH.Length = 0;
GenerateDIInterrupt(INT_TCINT);
g_ErrorCode = 0;
g_last_read_offset = (DVD_offset + m_DILENGTH.Length - 2048) & ~2047;
return ticks_until_TC;
}
// Returns the number of ticks it takes to read an amount of
// data from a disc, ignoring factors such as seek times.
// The result will be negative if the length is negative.
s64 CalculateDiscReadTime(u64 offset, s64 length)
s64 CalculateRawDiscReadTime(u64 offset, s64 length)
{
// The speed will be calculated using the average offset. This is a bit
// inaccurate since the speed doesn't increase linearly with the offset,