What USE=gallium currently does is to add the --enable-gallium flag to configure for misc packages (typically xf86-video-ati). I did that and checked that my x was using gallium...... which is not. The reason is the following : with current git trees, the gallium drivers are built, but not installed. People use LIBGL_DRIVERS_PATH to try it. (on irc:) [05:03] <airlied> orzel: gallium doesn't get installed or used by default [05:06] <airlied> orzel: generally we just use LIBGL_DRIVERS_PATH to pick the gallium driver So my understanding is that current live ebuilds actually build the gallium stuff somewhere, but do not install it and wipe the build directory.. and there is now way to test the gallium drivers in gentoo. I dont know about non-live ebuilds, i have not checked them. Reproducible: Always
Here is some more information from irc: [05:27] Just copy or symlink radeong_dri.so to r300_dri.so and point LIBGL_DRIVERS_PATH to that folder.
Yeah, we've churned USE flags a lot on mesa in the overlay and we're still not quite sure where we want to go. As for gallium, we used to provide a USE flag for it which never actually did anything since libGL never looks for gallium drivers... Maybe we should always build gallium drivers and use eselect-opengl to enable them? Food for thoughts... In any case, that's not the biggest priority ATM. Thanks for the bug report nonetheless. Cheers
This is fixed by eselect-mesa, now that gallium is used by default if USE="-classic" is set. If both classic and gallium USE flags are enabled, you can switch with eselect mesa.
