diff --git a/src/gallium/drivers/radeonsi/si_shader.c b/src/gallium/drivers/radeonsi/si_shader.c
index 77f24a8501c..e82ecf852e0 100644
--- a/src/gallium/drivers/radeonsi/si_shader.c
+++ b/src/gallium/drivers/radeonsi/si_shader.c
@@ -1947,7 +1947,7 @@ static void si_lower_ngg(struct si_shader *shader, nir_shader *nir)
       options.num_vertices_per_primitive = num_vertices ? num_vertices : 3;
       options.early_prim_export = gfx10_ngg_export_prim_early(shader);
       options.passthrough = gfx10_is_ngg_passthrough(shader);
-      options.use_edgeflags = gfx10_edgeflags_have_effect(shader);
+      options.use_edgeflags = gfx10_has_variable_edgeflags(shader);
       options.has_gen_prim_query = options.has_xfb_prim_query =
          sel->screen->info.gfx_level >= GFX11 && !sel->info.base.vs.blit_sgprs_amd;
       options.export_primitive_id = key->ge.mono.u.vs_export_prim_id;
diff --git a/src/gallium/drivers/radeonsi/si_shader.h b/src/gallium/drivers/radeonsi/si_shader.h
index 7db03acf619..d76c38f9a0a 100644
--- a/src/gallium/drivers/radeonsi/si_shader.h
+++ b/src/gallium/drivers/radeonsi/si_shader.h
@@ -1080,6 +1080,8 @@ void gfx9_get_gs_info(struct si_shader_selector *es, struct si_shader_selector *
 bool gfx10_is_ngg_passthrough(struct si_shader *shader);
 unsigned si_shader_lshs_vertex_stride(struct si_shader *ls);
 bool si_should_clear_lds(struct si_screen *sscreen, const struct nir_shader *shader);
+unsigned si_get_output_prim_simplified(const struct si_shader_selector *sel,
+                                       const union si_shader_key *key);
 
 /* Inline helpers. */
 
@@ -1117,19 +1119,17 @@ static inline bool si_shader_uses_bindless_images(struct si_shader_selector *sel
    return selector ? selector->info.uses_bindless_images : false;
 }
 
-static inline bool gfx10_edgeflags_have_effect(struct si_shader *shader)
+static inline bool gfx10_has_variable_edgeflags(struct si_shader *shader)
 {
-   if (shader->selector->stage == MESA_SHADER_VERTEX &&
-       !shader->selector->info.base.vs.blit_sgprs_amd &&
-       !(shader->key.ge.opt.ngg_culling & SI_NGG_CULL_VS_LINES))
-      return true;
+   unsigned output_prim = si_get_output_prim_simplified(shader->selector, &shader->key);
 
-   return false;
+   return shader->selector->stage == MESA_SHADER_VERTEX &&
+          (output_prim == MESA_PRIM_TRIANGLES || output_prim == MESA_PRIM_UNKNOWN);
 }
 
 static inline bool gfx10_ngg_writes_user_edgeflags(struct si_shader *shader)
 {
-   return gfx10_edgeflags_have_effect(shader) &&
+   return gfx10_has_variable_edgeflags(shader) &&
           shader->selector->info.writes_edgeflag;
 }
 
diff --git a/src/gallium/drivers/radeonsi/si_state.h b/src/gallium/drivers/radeonsi/si_state.h
index 8b7fd03e77e..54d1b3bfc71 100644
--- a/src/gallium/drivers/radeonsi/si_state.h
+++ b/src/gallium/drivers/radeonsi/si_state.h
@@ -678,8 +678,6 @@ void si_update_ps_inputs_read_or_disabled(struct si_context *sctx);
 void si_update_vrs_flat_shading(struct si_context *sctx);
 unsigned si_get_input_prim(const struct si_shader_selector *gs, const union si_shader_key *key,
                            bool return_unknown);
-unsigned si_get_output_prim_simplified(const struct si_shader_selector *sel,
-                                       const union si_shader_key *key);
 unsigned si_get_num_vertices_per_output_prim(struct si_shader *shader);
 bool si_update_ngg(struct si_context *sctx);
 void si_vs_ps_key_update_rast_prim_smooth_stipple(struct si_context *sctx);
diff --git a/src/gallium/drivers/radeonsi/si_state_shaders.cpp b/src/gallium/drivers/radeonsi/si_state_shaders.cpp
index 37c92cd42b6..263222c9041 100644
--- a/src/gallium/drivers/radeonsi/si_state_shaders.cpp
+++ b/src/gallium/drivers/radeonsi/si_state_shaders.cpp
@@ -1548,7 +1548,7 @@ static void gfx10_shader_ngg(struct si_screen *sscreen, struct si_shader *shader
        * for the GL_LINE polygon mode to skip rendering lines on inner edges.
        */
       if (gs_info->uses_invocationid ||
-          (gfx10_edgeflags_have_effect(shader) && !gfx10_is_ngg_passthrough(shader)))
+          (gfx10_has_variable_edgeflags(shader) && !gfx10_is_ngg_passthrough(shader)))
          gs_vgpr_comp_cnt = 3; /* VGPR3 contains InvocationID, edge flags. */
       else if ((gs_stage == MESA_SHADER_GEOMETRY && gs_info->uses_primid) ||
                (gs_stage == MESA_SHADER_VERTEX && shader->key.ge.mono.u.vs_export_prim_id))