----- Original Message ----- > On Fri, Dec 23, 2011 at 7:51 PM, Chia-I Wu <olva...@gmail.com> wrote: > > On Sat, Dec 24, 2011 at 12:37 AM, Ian Romanick > > <i...@freedesktop.org> wrote: > >> On 12/23/2011 07:20 AM, Jose Fonseca wrote: > >>> > >>> ----- Original Message ----- > >>>> > >>>> Hi list, > >>>> > >>>> Multiple driver support in EGL is hard to get right, if not > >>>> impossible. > >>>> On Linux desktop, we almost always want to use egl_dri2. It > >>>> allows > >>>> EGL > >>>> to loads DRI2 drivers, thus allowing it to share DRI2 drivers > >>>> with > >>>> libGL. > >>>> > >>>> In one case where the app wants to use OpenVG, libEGL needs to > >>>> load > >>>> egl_gallium instead. The problem comes from that we cannot know > >>>> that > >>>> an > >>>> OpenVG context is to be created until it is created. But before > >>>> a > >>>> context can be created, EGL needs to be initialized and an > >>>> EGLConfig > >>>> needs to be chosen. So when EGL is to be initialized, we need > >>>> to > >>>> load > >>>> and initilaize all EGL drivers. When an EGLConfig is to be > >>>> picked, > >>>> we > >>>> need to pick it from all drivers. > >>> > >>> > >>> Couldn't we restructure this such that OpenVG (and all other > >>> state > >>> trackers on Linux) still use a dri2 driver, but one which exposes > >>> an > >>> additional (gallium specific) interface? > >> I was going to suggest something similar. I think we want fewer > >> EGL > >> backends to test and maintain, not more. Right? > > I totally agree with that. I even had an unfinished branch for > > that. > > > > Note that this thread is about dropping multiple EGL driver > > support. > > The motivation for having OpenVG in DRI2 drivers is that we do not > > want multiple EGL drivers. The former should push the latter to > > happen more quickly, instead of preventing it from happening. > > The problem with exposing the Gallium Interface via the DRI interface > is that the DRI interface is public and stable while the Gallium one > is > not.
I think one doesn't invalidate the other. That is, it is technically feasible to have an unstable interface on top of an stable interface. In detail, we could add a stable extension DRI , which exposes Gallium (eg. DRI2GetGalliumScreen). Obviously, for things to work, it would be imperative that the libEGL.so and foo_dri.so were built together, which is already the case today. Jose _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
