Re: [PATCH 0/6] Misc display/sm501 clean ups and fixes

[BALATON Zoltan]

On Wed, 20 May 2020, BALATON Zoltan wrote:
> Hello,
>
> These are some small clean ups and changes to hopefully improve 2D
> engine performance and fix a security bug in it. I've only tested it
> lightly, haven't verified if breaking it is still possible. It's also
> known to change handling of right to left blits which may not be able
> to handle overlaping regions but the only guest known to use it
> (AmigaOS on sam460ex) seems to be OK with this so unless this is
> proven to be needed I won't try to fix that now, this could be
> addressed in later patches.

I've found a case where not handling right to left causes a problem (can 
be reproduced by scrolling window content which will do overlapping blits) 
so this will need some more work but the basic idea can be tested with 
this version.

Does anyone know how the X server or other users of pixman handle this as 
pixman does not seem to have support for other than left to right top to 
bottom blits?

Regards,
BALATON Zoltan