Metal Gear Acid (ULUS10006) :- Crashes during the introductory sequence in every build if Fast Memory is enabled.

[solarmystic]

Possibly related to this closed older report by @Avastia #2349 . Happens right before Teliko is about to meet Leone for the first time during the introductory sequence (just like #2349).

All builds are affected, from v0.7.6 all the way to the current git release on the buildbot, v0.9.6-789-g3d3b0b1 but was not considered a legitimate issue since the Fast Memory option was deemed unstable until it was enabled by default from v0.9.5-759-gebdab9f ebdab9f onwards and is now part of the first boot configuration.

Reproduction Method:-

1. Boot up the game using any revision from v0.9.5-759-gebdab9f onwards with default settings (which already has Fast Memory enabled). Enable Fast Memory manually if attempting to reproduce the issue with v0.9.5-759-gebdab9f and below.
2. Start a New Game and let the introductory sequence play out.
3. Right before Teliko meets Leone for the first time, the game will crash, taking down the emulator with it.

MSVC 2013 Stacktrace was rather useless since it only points to the disassembly (similar to #4759 which is also an issue related to Fast Memory.)

Log console shows the following lines when the crash should occur if Fast Memory is disabled instead:-

Temporary solution:-
Play through that portion of the game (or indeed, the entire game, see #4536) with Fast Memory disabled.

[hrydgard]

Yeah, invalid address accesses nearly always become crashes in fastmem mode. Need to figure out what causes them.

[unknownbrackets]

This kind of thing really needs a debug log, although only really a couple hundred lines before the invalid access are probably needed.

-[Unknown]

[solarmystic]

@unknownbrackets

Relevant Debug log from the same portion of the game (7z compressed):-
https://www.mediafire.com/?kqqk8lb8891hlko

[unknownbrackets]

Well, there are some interrupts / probably GE signals right before that. Could be something is happening in an unexpected order. It also calls sceDisplayGetAccumulatedHcount() right near there, and then 2=sceCtrlReadBufferPositive(0bfffd90, 8) right before.

Hmm. Could even be related to fps I guess. Does the game run at the correct fps per cwcheat on a PSP?

-[Unknown]

[solarmystic]

It runs at a fixed 30 FPS which I believe is correct. Both Metal Gear Acid games do.

The others (Portable Ops, Portable Ops +, Peace Walker) seem to have variable FPS ranging from 20 to 60 depending on the scene.

[sum2012]

Metal Gear Acid still have problem in
v0.9.8-1330-g9fc37ca-windows-amd64
debug log:
https://drive.google.com/file/d/0B3OaSdeV0L8kd2NSSDluR2FkRFE/edit?usp=sharing
Disassumby

[sum2012]

No invalid address when Teliko meets Leone in v0.9.9.1-1505-gcf577e9-windows-amd64
log:https://gist.github.com/sum2012/413773470ee64e377170

[sum2012]

Need someone test #4536

[sum2012]

I think that can close this too