--- Eric Anholt <[EMAIL PROTECTED]> wrote: > On Mon, 2004-08-23 at 15:24, Ian Romanick wrote: > > Thomas Hellström wrote: > > > > > As some of you might have read on another thread, there is a > discussion > > > how to handle the X server (and possibly other) 2d contexts in the > via / > > > unichrome family of drivers that expects certain 2d engine register > > > values to stay the same even when other contexts or DMA commands > have > > > played. > > > > > > Looking at the now obsolete gamma driver and ffb_context.c, some > > > register values are saved at context switches whereas in other > drivers > > > this does not seem to happen. > > > > > > What is the common practice? That all clients always reinitialize > the > > > engines every time they are used or that the drm saves the registers > > > > that are commonly used by different clients as part of the context > switch? > > > > The common practice is to define a set of register "groups", and > define > > a bit mask for with 1 bit per group (usually called "dirty bits"). > When > > a context gets the hardware lock, it checks to see if any other > context > > has held the lock since the last time it held it. If another context > > has, it looks at the bit mask (stored in the SAREA). Any set dirty > bits > > mean the some other context modified some register in that group. The > > > dirty register(s) is then reset to the value expect by the context now > > > holding the lock. > > Another way is what the radeon/r200 drivers do: When you grab the lock > from someone else, *all* state is dirty. You can see an example in > radeon_dri.c. When we grab the lock, we mark the 3d state invalid so > that the next use of it (Render acceleration) resets it all. > > To be totally correct, in my opinion, the EnterServer for Radeon should > be resetting some of the 2d state that it depends on, as well. As it > is, it looks like if someone wanted to set things like the default > offset in the 3d driver, they'd have to update the 2d driver to reset it > when grabbing the lock, bump the DDX version, and check for that version > in the 3d driver and deal with it appropriately. > Are there alot of registers, more then 300? If not why would they be broken up into groups, I'm guessing each function/group only has 7 to 10 registers. It seams like you would wast more cycles on conditional jumps then on just pushing the state.
> -- > Eric Anholt [EMAIL PROTECTED] > http://people.freebsd.org/~anholt/ [EMAIL PROTECTED] > > > > > ------------------------------------------------------- > SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media > 100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33 > Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift. > http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285 > -- > _______________________________________________ > Dri-devel mailing list > [EMAIL PROTECTED] > https://lists.sourceforge.net/lists/listinfo/dri-devel > __________________________________ Do you Yahoo!? Yahoo! Mail Address AutoComplete - You start. We finish. http://promotions.yahoo.com/new_mail ------------------------------------------------------- SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media 100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33 Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift. http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285 -- _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
