UMD seek delay isn't emulated at all, causing some games not to boot

[thedax]

This is a continuation of the discussion in #4887.

Some versions of Pangya: Fantasy Golf don't boot, but instead hang forever with sceKernelStopUnloadSelfModuleWithStatus.

What we know so far:

1. If sceIoRead's delay is increased to 19,999 microseconds or later (no less, else it won't boot, at all), the game will boot fine.
2. It could be a possible threading or schedule issue, where things aren't being ran at the expected time, so the game freaks and dies.
3. Unknown's initial UMD seek delay emulation did seem to help, but broke other games (notably, Jeanne D'Arc's videos stopped playing IIRC), so it wasn't merged.

[unknownbrackets]

Looks like Dolphin emulates this pretty carefully:
https://github.com/dolphin-emu/dolphin/pull/327/files

Seems like doing it right will require a lot of testing.

-[Unknown]

[hrydgard]

Doing it completely right would also increase load times drastically to the terrible load times of the real PSP so it's a double edged sword.. (of course, you can always unthrottle your way past loads).

Most major Gamecube games were actually really well tuned to load quickly, unlike PSP games.

[unknownbrackets]

That's true, and another worry of mine. I really don't want to have accurate loading times, except where it really matters...

-[Unknown]

[xsacha]

Isn't there a way to modify 'PSP time'. That is, fast forward PSP time but take no real time to do so. Especially for loading.

[hrydgard]

I'm not sure if you are being facetious, but that's our current fast-forward functionality. It's pretty nice that load times are fast even without it though.

[xsacha]

Fast-forward? No, I wasn't aware.
Unless you mean turbo where you hit TAB and it unthrottles.

Not sure if what I was talking about is already implemented but I was thinking from the perspective that PSP time is separate to the host time (as Timer Hack exploits), so when there is a UMD access, it can say that 5 seconds passed when it was really 0.2 seconds, for eg.
This might be more complicated if the access happens while playing and an in-game element expects the load to take 5 seconds but at the same time doesn't pause the gameplay.

[hrydgard]

Yeah, that's unthrottling.

It would be highly annoying to do that when games load stuff in the background, yeah. That happens quite a lot.

[unknownbrackets]

More importantly, many games will play music. Most people don't like it when the music and voices suddenly fast forward just because the screen isn't displaying anything.

-[Unknown]

[unknownbrackets]

This is somewhat supported now with an option, though it's not perfect. Should we keep this open?

-[Unknown]

[thedax]

I'll close this, the ISO I have of Pangya that exhibits the problem boots fine when the UMD seek delay is being used. I'll make a note of it in my Pangya thread on the forum, if nobody else has.

[unknownbrackets]

Cool. It still needs work but apparently it helps other games too... Gotta figure out a good compromise because it breaks a few games also.

Long time no see. Hope things are going well.

-[Unknown]

[thedax]

Likewise. I've been messing with 3DS homebrew lately, so I more or less vanished from the PSP scene..it looks like I've missed a hell of a lot since then.