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Collect probably IO timing related problems #7647
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The current logic is really basic, it's just this: if (abs((int)lastReadBlock_ - (int)secNum) > 100) {
// This is an estimate, sometimes it takes 1+ seconds, but it definitely takes time.
usec = 100000;
} More correctly, the time on a UMD will vary based on:
For example, World Neverland might be reading things very efficiently with things laid out on separate tracks that are near each other. Or our delays are just too high for it.... or, it might simply run slow on PSP-1000 devices, I guess (probably not.) However, there's a simpler solution: if all of these games work on a PSP as iso/cso files on a memory stick, then presumably it can't depend on the above factors of rotation speed and whatever. It's probably a lot easier to simulate the access speed and latencies of flash storage (we already try, but we're a bit too aggressively fast.) I don't think that layer has "seek delay" emulation, so theoretically we shouldn't need it either. -[Unknown] |
Pangya: Fantasy Golf won't work on memory stick with cfw 660pro-c2 |
The demo of Monster Hunter Freedom Unite has a black screen after language selection. |
Confirmed working DJ MAX titles with Simulate UMD Delays option. |
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It already seems it helps more games than it breaks, so I might change the default soon. |
Don't have the other marked as hanging with "Simulate UMD delays", but GitS:SAC works fine with it for me. |
The default setting for "I/O timing method" is still "Fast (lag on slow storage)". |
I'll run more tests too, but it would seem like Driver 76 should be added to the list of games for which "Simulate UMD delays" helps, as per #12054. |
I use "Simulate UMD delays" for the 4 games I own but only Castlevania Dracua X benefits from it I guess. Would changing the default value "Fast" to "Simulate UMD delays" be that bad today? It's been 4 years since this issue surfaced after all. |
I took a stab at async IO using threads. It kinda works, but for example LittleBigPlanet gives errors about calling pthreads on non-pthreads (within the game, not host pthreads.) It doesn't seem related to callbacks... master...unknownbrackets:io-async -[Unknown] |
@unknownbrackets I still get invalid address in Mahou Shoujo Madoka Magica Portable in beginning story in your change. debug log: https://drive.google.com/file/d/1UFuDEcIW0SzEdOr35iXbAYIdEZ1s229o/view?usp=sharing |
I made sure the thread waits for the entire IO operation, and fixed some file open issues. This seems to have made the branch more stable - at least, I'm no longer seeing errors in the chunk of games I tested. master...unknownbrackets:io-async -[Unknown] |
Neat, sounds promising. |
For reference: link to the merged pull request. |
It'd be interesting to validate if "Simulate UMD Delays" is no longer needed for those issues, or no longer breaks those games. Host is probably always going to be a wildcard, but if those games no longer are helped, that'd be useful information too. -[Unknown] |
Now "Host" behaves the same as "Fast": a blocking black screen. |
The behavior of Host is non-deterministic. Meaning:
-[Unknown] |
Thanks for your explanations, but I'm having trouble understanding the interest of a non-deterministic option? Isn't it confusing for the user? |
Host mode will provide the fastest possible non-blocking loading, I think. Maybe it's not worth it though, I would be open to getting rid of it. |
Well, Host is never faster than Fast. It mostly exists for slow storage. Example: let's say I'm streaming the disc via network from my PC. Usually, my connection is fast but occasionally it may get slow due to wifi signal noise nearby, etc. In that situation, Fast and Simulate UMD Delays would just stall and hang if the storage was slow. Music would stop playing, loading screens would stop spinning, and emulation would grind to a halt. That's the cost of determinism. In contrast, Host will take as long as it takes. Again, never less time than Fast. In some ways, this is realistic. On a PSP, if the UMD had stopped spinning, a disc read would potentially take a couple seconds to fulfill. So games are often prepared for an IO operation to be slow: music keeps playing, you see loading animations, and everything works more or less as it should. It can be faster than Simulate UMD Delays, but that will not be the common case. Most (or all) operations will be slower than Simulate UMD Delays. So Host is not really bad imho, it's just not deterministic. If we removed it, it'd significantly impact the usability of remote disc streaming. -[Unknown] |
Argh, yes, thanks for setting me straight. I was mainly thinking of the non-blocking nature of it. Yeah, not getting rid of it. |
It seems some games like F1 2006 and Arctic Adventures: Polar's Puzzles forced to switch simulated UMD delays via compat.ini |
It seems Arctic Adventures: Polar's Puzzles need Simulate UMD Delays in |
It shouldn't need it though as it's a mini and doesn't run from UMD... Very strange, probably accidentally covers some other problem.. |
perhaps for devices with low storage access speeds and RAM to spare, a mode where it pre-caches the entire ISO into RAM at start and then it could presumably safely use 'fast' or 'simulate UMD delays' mode. i think beetle-psx does something like this: libretro/beetle-psx-libretro@ee40afa PSP ISOs are about 500MB, right? quite a lot of devices could probably spare that amount of RAM. |
We already have an option to preload the entire ISO into RAM. PSP games are often as much as 1.8 GB. I don't believe this option helps any of the issues linked here, though. This issue doesn't really have anything to do with device speed. It has to do with games that accidentally contain bugs, and malfunction when the IO timing doesn't match what happened on a PSP. For example, on a real PSP the disc spins down after not being used for a while (in part because it's silly loud, but it also burns battery to spin it.) Maybe a game developer "knew" that the disc would always need 2 seconds to spin up when certain code ran, so just assumed that the IO could not possibly complete for 2 seconds. A PS1 has simpler storage emulation needs. PSP games have to deal with:
Most of the above problems are problems a PS1 emulator doesn't have. It just has to emulate a CD-ROM drive (which can still have complex timing, don't get me wrong.) Currently, PPSSPP doesn't do much of the above, though. It:
We currently do nothing to emulate:
We also do some other things, such as CPU operations, HLE syscalls, and GPU drawing faster or slower than we should. This can interact with IO timing. -[Unknown] |
Mahou Shoujo Madoka Magica Portable is solved by #15930 |
Welcome to test new IO timing method "Simulate UMD slow reading speed" in any game |
Meaning problems got help by changing I/O timing method to "HOST" or"Simulate UMD delays".
"Simulate UMD delays" helps the following games
"Host" helps the following games
"Simulate UMD delays" breaks the following games
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