[Mesa-dev] [PATCH] egl: Mention if swrast is being forced

[Erik Faye-Lund]

On Mon, 2019-11-11 at 10:44 +0200, Martin Peres wrote:
> On 31/10/2019 09:35, Chris Wilson wrote:
> > The system can be disabling HW acceleration unbeknowst to the user,
> > leading to a long debug session trying to work out which component
> > is
> > failing. A quick mention that it is the environment override would
> > be
> > very useful.
> > ---
> >  src/egl/main/egldriver.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/src/egl/main/egldriver.c b/src/egl/main/egldriver.c
> > index 0d8919aa0e1..132b12ab4cb 100644
> > --- a/src/egl/main/egldriver.c
> > +++ b/src/egl/main/egldriver.c
> > @@ -92,6 +92,8 @@ _eglMatchDriver(_EGLDisplay *disp)
> >     /* set options */
> >     disp->Options.ForceSoftware =
> >        env_var_as_boolean("LIBGL_ALWAYS_SOFTWARE", false);
> > +   if (disp->Options.ForceSoftware)
> > +      _eglLog(_EGL_DEBUG, "Found 'LIBGL_ALWAYS_SOFTWARE' set,
> > forcing swrast");
> 
> Maybe we want to remain generic rather than just saying swrast, but
> not
> sure if LIBGL_ALWAYS_SOFTWARE would enable llvmpipe if available
> rather
> than swrast. Maybe we can say "will use a CPU renderer".
> 

Yes, it will pick up llvmpipe usually. Or SWR. It can even pick up Zink
exposed as an software-rasterizer, if enabled. But Zink IIRC is the
last resort.