On Sat, 16 Jun 2018 21:40:10 -0700 Matt Turner <matts...@gentoo.org> wrote:
> Hello, > > VIDEO_CARDS is an annoying mess. We used to have radeon, intel, and > some others in media-libs/mesa's VIDEO_CARDS. radeon and intel > corresponded to disparate sets of drivers -- VIDEO_CARDS=radeon has > meant classic r100, r200, r300, and r600 drivers and gallium r600 and > radeonsi drivers. VIDEO_CARDS=intel has meant classic i915 and i965 > drivers as well as gallium i915. > > I added more-specific VIDEO_CARDS for those separate drivers a few > years ago, so that users could set VIDEO_CARDS="radeon radeonsi" and > only get the one radeonsi driver they actually wanted while still > enabling support for x11-libs/libdrm's radeon support code which is > used by most of those radeon drivers. Of course some users want this > control and others don't care at all. > > The confusion comes in with "classic" DRI drivers vs Gallium drivers. > The Gallium abstraction layer allows a hardware driver to handle > multiple APIs -- OpenGL, D3D9, OpenCL, video decode APIs, etc. For > instance, users try to build the classic i965 driver (there is no > Gallium driver for this hardware) with USE=opencl or USE=vaapi and > don't understand why they didn't get what they wanted (or REQUIRED_USE > prevents them from doing so). > > Should of Mesa's USE flags, d3d9, llvm, lm_sensors, opencl, openmax, > unwind, vaapi, vdpau, xa, and xvmc are Gallium-only. Should I make a > USE_EXPAND for Gallium-only options to attempt to avoid confusion? > Another point of confusion: not all Gallium drivers support all of > these features. For instance only the r600 and radeonsi drivers > support OpenCL. How to best handle this? > > It seems like at one extreme you build an extensive set of > REQUIRED_USE conditions that force users to micromanage their USE > flags, or you let them enable all sorts of impossible combinations and > deal with the confused bug reports. > > I would like to somehow get rid of the 'classic' and 'gallium' USE > flags entirely, but I'm not totally sure how. Maybe I can enable them > dependent on VIDEO_CARDS... > > Suggestions welcome. > What about creating a tiny pkg that has all the combinations in a dictionary and can set the USE and VIDEO_CARDS flags according to the video card(s) you have. This would be along the same lines as the app-portage/cpuid2cpuflags pkg. Then the pkg is updated as new drivers and combinations are changed. Perhaps have it run in pkg_postisnt to print any irregularities it finds and ewarn they need fixing. -- Brian Dolbec <dolsen>
