diff --git a/src/gallium/auxiliary/nir/nir_to_tgsi_info.c b/src/gallium/auxiliary/nir/nir_to_tgsi_info.c
index 4dbf252c89f..098f88676ff 100644
--- a/src/gallium/auxiliary/nir/nir_to_tgsi_info.c
+++ b/src/gallium/auxiliary/nir/nir_to_tgsi_info.c
@@ -328,6 +328,8 @@ static void scan_instruction(const struct nir_shader *nir,
             case INTERP_MODE_NONE:
                if (glsl_base_type_is_integer(base_type))
                   break;
+               if (var->data.per_primitive)
+                  break;
 
                FALLTHROUGH;
             case INTERP_MODE_SMOOTH:
@@ -461,7 +463,8 @@ void nir_tgsi_scan_shader(const struct nir_shader *nir,
       }
    }
 
-   if (gl_shader_stage_is_compute(nir->info.stage)) {
+   if (gl_shader_stage_is_compute(nir->info.stage) ||
+       gl_shader_stage_is_mesh(nir->info.stage)) {
       info->properties[TGSI_PROPERTY_CS_FIXED_BLOCK_WIDTH] = nir->info.workgroup_size[0];
       info->properties[TGSI_PROPERTY_CS_FIXED_BLOCK_HEIGHT] = nir->info.workgroup_size[1];
       info->properties[TGSI_PROPERTY_CS_FIXED_BLOCK_DEPTH] = nir->info.workgroup_size[2];
@@ -517,7 +520,7 @@ void nir_tgsi_scan_shader(const struct nir_shader *nir,
 
          switch (variable->data.interpolation) {
          case INTERP_MODE_NONE:
-            if (glsl_base_type_is_integer(base_type)) {
+            if (glsl_base_type_is_integer(base_type) || variable->data.per_primitive) {
                info->input_interpolate[i] = TGSI_INTERPOLATE_CONSTANT;
                break;
             }
diff --git a/src/gallium/auxiliary/tgsi/tgsi_from_mesa.c b/src/gallium/auxiliary/tgsi/tgsi_from_mesa.c
index 9e39497114c..4716aaad17a 100644
--- a/src/gallium/auxiliary/tgsi/tgsi_from_mesa.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_from_mesa.c
@@ -50,6 +50,9 @@ tgsi_get_generic_gl_varying_index(gl_varying_slot attr,
       return attr - VARYING_SLOT_TEX0;
    }
 
+   if (attr == VARYING_SLOT_CULL_PRIMITIVE)
+      return 0;
+
    assert(0);
    return 0;
 }
@@ -145,7 +148,11 @@ tgsi_get_gl_varying_semantic(gl_varying_slot attr,
       *semantic_name = TGSI_SEMANTIC_VIEWPORT_MASK;
       *semantic_index = 0;
       break;
-
+   case VARYING_SLOT_CULL_PRIMITIVE:
+      /* mesh only, just pick something random */
+      *semantic_name = TGSI_SEMANTIC_PATCH;
+      *semantic_index = 0;
+      break;
    case VARYING_SLOT_TEX0:
    case VARYING_SLOT_TEX1:
    case VARYING_SLOT_TEX2: