From c6b24b4cc27d0c4877f974ab9a404a1afca2b9a0 Mon Sep 17 00:00:00 2001
From: Qiang Yu <yuq825@gmail.com>
Date: Tue, 25 Feb 2025 15:19:18 +0800
Subject: [PATCH] glsl: disable mesh shader output remove when separate shader
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Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Acked-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/36405>
---
 src/compiler/glsl/gl_nir_linker.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/src/compiler/glsl/gl_nir_linker.c b/src/compiler/glsl/gl_nir_linker.c
index 94624605644..106d04e9534 100644
--- a/src/compiler/glsl/gl_nir_linker.c
+++ b/src/compiler/glsl/gl_nir_linker.c
@@ -555,11 +555,18 @@ set_always_active_io(nir_shader *shader, nir_variable_mode io_mode)
 static void
 disable_varying_optimizations_for_sso(struct gl_shader_program *prog)
 {
-   unsigned first, last;
    assert(prog->SeparateShader);
 
-   first = MESA_SHADER_MESH_STAGES;
-   last = 0;
+   if (prog->_LinkedShaders[MESA_SHADER_MESH]) {
+      if (!prog->_LinkedShaders[MESA_SHADER_FRAGMENT]) {
+         set_always_active_io(prog->_LinkedShaders[MESA_SHADER_MESH]->Program->nir,
+                              nir_var_shader_out);
+      }
+      return;
+   }
+
+   unsigned first = MESA_SHADER_MESH_STAGES;
+   unsigned last = 0;
 
    /* Determine first and last stage. Excluding the compute stage */
    for (unsigned i = 0; i < MESA_SHADER_COMPUTE; i++) {
@@ -573,7 +580,7 @@ disable_varying_optimizations_for_sso(struct gl_shader_program *prog)
    if (first == MESA_SHADER_MESH_STAGES)
       return;
 
-   for (unsigned stage = 0; stage < MESA_SHADER_MESH_STAGES; stage++) {
+   for (unsigned stage = 0; stage < MESA_SHADER_STAGES; stage++) {
       if (!prog->_LinkedShaders[stage])
          continue;