From e3428419fb9ccd01e8f1b1f7f2b9d864a36f38d6 Mon Sep 17 00:00:00 2001
From: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Date: Fri, 12 Feb 2021 12:27:47 -0500
Subject: [PATCH] zink: fix slot mapping for legacy gl io with tess stages

e.g., gl_BackColor is a thing

Fixes: aec03553e1b ("zink: fix tess shader i/o variables")

Reviewed-by: Dave Airlie <airlied@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/9019>
---
 src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c b/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c
index 4e11796e2af..e055b868796 100644
--- a/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c
+++ b/src/gallium/drivers/zink/nir_to_spirv/nir_to_spirv.c
@@ -413,9 +413,9 @@ handle_handle_slot(struct ntv_context *ctx, struct nir_variable *var, bool outpu
    if (var->data.patch) {
       assert(var->data.location >= VARYING_SLOT_PATCH0);
       return var->data.location - VARYING_SLOT_PATCH0;
-   } else if ((output && ctx->stage == MESA_SHADER_TESS_CTRL) ||
-              (!output && ctx->stage == MESA_SHADER_TESS_EVAL)) {
-      assert(var->data.location >= VARYING_SLOT_VAR0);
+   } else if (var->data.location >= VARYING_SLOT_VAR0 &&
+              ((output && ctx->stage == MESA_SHADER_TESS_CTRL) ||
+              (!output && ctx->stage == MESA_SHADER_TESS_EVAL))) {
       return var->data.location - VARYING_SLOT_VAR0;
    }
    return handle_slot(ctx, var->data.location);