On Wed, May 27, 2009 at 6:20 PM, Ville Syrjälä <syrj...@sci.fi> wrote: > On Wed, May 27, 2009 at 05:50:51PM -0400, Alex Deucher wrote: >> On Wed, May 27, 2009 at 5:09 PM, Evgeny M. Zubok <evgeny.zu...@tochka.ru> >> wrote: >> > >> > I have made the first attempt to implement basic `Copy' and `Solid' EXA >> > functions in xf86-video-s3, but soon came to intention that EXA support >> > is not possible. Is there mistake in my thinking below? >> > >> > S3's Graphic Processor (S3 GP) is able to copy areas only in terms of >> > coordinates, i. e. it can copy rectangle from (src-x, src-y) to (dest-x, >> > dest-y) with width w and height h (Fig. 1). This method is used in XAA >> > ScreenToScreenCopy function. But S3 GP hasn't mean to copy offscreen >> > pixmaps in format presented on Fig. 2 to framebuffer, i. e. there is no >> > way to write the pixmap's offset and pitch directly into GP registers to >> > make subsequent copying. I looked up on the code of few other drivers >> > where EXA is implemented (ati, trident, mga) -- all these chips have the >> > possibility to write offset and pitch of pixmap into their GP. >> > >> > Although the method (by means of Pixel Transfer Register) exists to >> > upload pixmap from the system memory to S3's offscreen memory in >> > required format (Fig. 1) (I didn't try it), such offscreen memory >> > organization will not be understandable to the EXA offscreen memory >> > manager. Most probably this will follow to incorrect pixmap migration >> > and overwriting previously uploaded pixmaps. >> > >> > The objection above sounds like the judgement to EXA support in S3 >> > driver. No? >> >> Looks like no dice for EXA. Fixed pitches, no offsets... ouch. > > Why wouldn't it work if you just allocate everything using the same > pitch? Or does the allocator make some assumptions about the pitches the > hardware can handle?
The allocator doesn't support a fixed pitch, only pitch alignment. You could probably hack something together and disable offscreen pixmaps, but I don't think it would be worth the effort as you'd probably end up falling back in a lot of cases and the lack offscreen pixmaps would hurt performance. Alex _______________________________________________ xorg mailing list xorg@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/xorg
