Digital Devil Saga 1 & 2 two-threaded freezes

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It's very old bug of PCSX2, from 0.9.2. But recently there is new behavior,
witch could help to fix the problem.

Issue is in DDS1, DDS2 and SMT: Nocturne games of Atlus, only in 2-threaded
mode (in single threaded no problem). From time to time game freezes, no
input reaction, no screen updating. But ESC-key is worked, so user could
load old save state.

A new behavior is in counters.c:555 string, there is 
SysPrintf( " ** vSync > Abnornal Scanline Count: %d\n", hsc );
message just at the same time as freeze. 

BTW, Abnoral -- is Abnormal, isn't it?

Original issue reported on code.google.com by Zeydl...@gmail.com on 25 Nov 2008 at 6:38

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Interesting.  Abnormal scanline counts should only occur during video mode 
changes,
which generally only occur during game init and before/after FMV movies.  It's
interesting if it happens without a mode change!

In any case there are still two known problems with the MTGS, and they could be
causing this to happen.  First there is a GIF transfer mode that is implemented 
very
poorly (GS memory read mode, and it's full of race conditions), and secondly 
it's
possible for games to mis-read the wrong values from GS registers.

I'll see about resolving those in the near future, and hopefully they'll solve 
this
too in the process.

Original comment by Jake.Stine on 26 Nov 2008 at 2:27

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Well, here is the last freeze I caught. No vsync message.

Original comment by Zeydl...@gmail.com on 26 Nov 2008 at 6:04

Attachments:

• dds2_freeze.GIF

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Yes this should be fixed now, as of r377.  Rama invested nearly an hour into DDS
without any freezes and it would more commonly crash on his machine within 
minutes
usually.  But it is a random thing so a little more testing is probably in 
order. 
Let me know if you have any issues.

Original comment by Jake.Stine on 3 Dec 2008 at 1:57

• Changed state: Started

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Well, it's seems there is several independent confirmation for DDS1 and 
SMT:Nocturne
(which also has this problem)

Original comment by Zeydl...@gmail.com on 3 Dec 2008 at 3:08

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This appears to have fixed a frequent crash/freeze bug in TOTA as well.  Still 
going
to leave it open until we can get a little more testing in.

Original comment by Jake.Stine on 3 Dec 2008 at 4:54

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There is still a crash issue with DDS under MTGS mode.  It happens after the
conclusion of battles, and results in instability followed by a crash.  I'm 
currently
looking at the GIFtag 'dummy' handler as the culprit, and writing a new one 
based on
GSDX's GIFtag handler.  I think that this problem was masked over (more or 
less) in
older versions of the MTGS due to the way the old MTGS still allowed the GS 
plugin to
throw its own GIFtag IRQs.  The extra IRQs could cause problems in games that 
are
GPU-limited, but would have actually masked over GIFtag bugs in games that were 
not
GPU limited.

Original comment by Jake.Stine on 10 Dec 2008 at 12:00

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Update: Apparently the new VTLB build fixes the post-battle crashing problems.  
I'm
still not sure why the VM build crashes, nor why VTLB fixes it.  But it's still 
kinda
good news in a sense. :)

Original comment by Jake.Stine on 24 Dec 2008 at 3:00

• Changed state: Accepted

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This bug was fixed with an MTGS patch (exact revision I forget, not caring 
enough to
look it up right now... :)

Original comment by Jake.Stine on 2 Feb 2009 at 4:03

• Changed state: Fixed