On Wed, 11 Jul 2001, Aleksandr Koltsoff wrote:
> Is it possible to wait for the start of vert refresh sync
LibGGIMISC does this, where it is supported, as Christoph mentioned.
Supported targets are svgalib and fbdev on a Matrox card (the only
fbdev kernel driver that supports this is Matrox.) I haven't looked
closely at it yet, but it looks like there is potentiall for support
for this to be added to the XF86 DGA target.
> or maybe even
> combine a batch of screen-update operations that will all run at vert
> refresh sync?
No targets support this king of VRT/VBL operation yet, so the feature
has not been added to LibGGIMISC, but it is planned.
> All gfx-chips that I've read the specs for support the IRQ9 (or equivalient
> in PCI) when the CRT-controllers start the VR-period.
IRQ is a horrible way to do this and should nly be used as a suppliment
to a proper v-blank detection/prediction system -- check out the in-tree
docs in LibGGIMISC; somewhere in there is a full explanation of why and what
the best way would be. I've played a bit with the "best way", but
nothing operational yet, however if you like working with discrete
math in real-time situtaions, then I can send what code I have jotted
down to you for fun :-).
--
Brian
