On Tue, 2008-02-19 at 00:35 +0100, Clemens Koller wrote: > [EMAIL PROTECTED] schrieb: > > On Mon, 18 Feb 2008 08:18:47 +0100, Krzysztof Helt said: > >> I know two fb drivers which use endianess information (pm2fb and > >> s3c2410fb). > >> Both resolve endianess at driver level. Actually, both handle it by > >> setting special > >> bits so the graphics chip itself reorder bytes to transform foreign > >> endianess. > >> I understand that this patch is for chips which cannot reorder bytes by > >> themselves. > > > > Does anybody know of such a chip that's actually available in the wild? Or > > are > > we writing drivers for speculative possible chips? > > > > I had troubles with the Silicon Motion SM501/SM502 endianess on PowerPC PCI > vs. LocalBus. > The chip also has a register to swap endianess, but that seems to only affect > some > LocalBus modes. > The current fb and X drivers are working, but when it comes to font > aliasing and hw-acceleration, the problems start to rise again...
Most "sane" gfx chips nowadays provide configurable surfaces that allow to perform the swap when writing/reading from regions of the framebuffer, with the ability to set a different swapper setting (based on bit depth) per region. Then there is also the risk that your PCI<->Localbus has been wired improperly :-) Ben. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-dev
