i965: Only turn on ARB_compute_shader if we can write registers.

Compute shaders require reconfiguring the L3 for shared local memory
support.  We have to be able to write the L3 registers to do that.

This effectively turns off compute shaders prior to Kernel 4.2.

(Previously, the extension enable was in an API_OPENGL_CORE conditional.
However, that isn't necessary - core Mesa extension handling already
restricts it properly.  I've moved it out in this patch.)

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>

diff --git a/src/mesa/drivers/dri/i965/intel_extensions.c b/src/mesa/drivers/dri/i965/intel_extensions.c
index e1338e92e15a0dae6a2d5d5f43dc8cd1a9ce1b41..889f7cbb5c1018d7dd6122e62fe28bf7117d68fd 100644 (file)
--- a/src/mesa/drivers/dri/i965/intel_extensions.c
+++ b/src/mesa/drivers/dri/i965/intel_extensions.c
@@ -346,6 +346,9 @@ intelInitExtensions(struct gl_context *ctx)
          ctx->Extensions.ARB_transform_feedback3 = true;
          ctx->Extensions.ARB_transform_feedback_instanced = true;
 
+         if (ctx->Const.MaxComputeWorkGroupSize[0] >= 1024)
+            ctx->Extensions.ARB_compute_shader = true;
+
          if (brw->intelScreen->cmd_parser_version >= 2)
             brw->predicate.supported = true;
       }
@@ -357,8 +360,6 @@ intelInitExtensions(struct gl_context *ctx)
          ctx->Extensions.ARB_viewport_array = true;
          ctx->Extensions.AMD_vertex_shader_viewport_index = true;
          ctx->Extensions.ARB_shader_subroutine = true;
-         if (ctx->Const.MaxComputeWorkGroupSize[0] >= 1024)
-            ctx->Extensions.ARB_compute_shader = true;
       }
    }