mesa: Track fixed-function fragment shader as a shader

Previously the fixed-function fragment shader was tracked as a
gl_program.  This means that it shows up in the driver as a Mesa IR
program instead of as a GLSL IR program.  If a driver doesn't generate
Mesa IR from the GLSL IR, that program is empty.  If the program is
empty there is either no rendering or a GPU hang.

Signed-off-by: Ian Romanick <[email protected]>
Reviewed-by: Eric Anholt <[email protected]>
Acked-by: Kenneth Graunke <[email protected]>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/i965/gen7_wm_state.c b/src/mesa/drivers/dri/i965/gen7_wm_state.c
index 1468fcc1278..32222f922d8 100644
--- a/src/mesa/drivers/dri/i965/gen7_wm_state.c
+++ b/src/mesa/drivers/dri/i965/gen7_wm_state.c
@@ -166,7 +166,9 @@ upload_ps_state(struct brw_context *brw)
    dw2 |= (ALIGN(brw->sampler.count, 4) / 4) << GEN7_PS_SAMPLER_COUNT_SHIFT;
 
    /* Use ALT floating point mode for ARB fragment programs, because they
-    * require 0^0 == 1.
+    * require 0^0 == 1.  Even though _CurrentFragmentProgram is used for
+    * rendering, CurrentFragmentProgram is used for this check to
+    * differentiate between the GLSL and non-GLSL cases.
     */
    if (intel->ctx.Shader.CurrentFragmentProgram == NULL)
       dw2 |= GEN7_PS_FLOATING_POINT_MODE_ALT;