Merge pull request #3632 from mmastrac/dvd_signedness

[DVD] Signedness fix in realistic timing path

Data/Sys/GameSettings/RPJ.ini

@@ -2,7 +2,6 @@
 
 [Core]
 # Values set here will override the main Dolphin settings.
-FastDiscSpeed = True
 
 [EmuState]
 # The Emulation State. 1 is worst, 5 is best, 0 is not set.

Source/Core/Core/HW/DVDInterface.cpp

@@ -1301,7 +1301,7 @@ u64 SimulateDiscReadTime(u64 offset, u32 length)
 	u64 disk_read_duration = CalculateRawDiscReadTime(offset, length) +
 		SystemTimers::GetTicksPerSecond() / 1000 * DISC_ACCESS_TIME_MS;
 
-	if (offset + length - s_last_read_offset > 1024 * 1024)
+	if (offset + length > s_last_read_offset + 1024 * 1024)
 	{
 		// No buffer; just use the simple seek time + read time.
 		DEBUG_LOG(DVDINTERFACE, "Seeking %" PRId64 " bytes",