radeonsi/gfx9: work around a GPU hang due to broken indirect indexing in LLVM

Fixes: 6d19120da85 "radeonsi/gfx9: workaround for INTERP with indirect indexing"
Cc: 18.1 <mesa-stable@lists.freedesktop.org>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>

diff --git a/src/gallium/drivers/radeonsi/si_get.c b/src/gallium/drivers/radeonsi/si_get.c
index d4e0eab..c31ab43 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_get.c
+++ b/src/gallium/drivers/radeonsi/si_get.c
@@ -494,6 +494,15 @@ static int si_get_shader_param(struct pipe_screen* pscreen,
                    !sscreen->llvm_has_working_vgpr_indexing)
                        return 0;
 
+               /* Doing indirect indexing on GFX9 with LLVM 6.0 hangs.
+                * This means we don't support INTERP instructions with
+                * indirect indexing on inputs.
+                */
+               if (shader == PIPE_SHADER_FRAGMENT &&
+                   !sscreen->llvm_has_working_vgpr_indexing &&
+                   HAVE_LLVM < 0x0700)
+                       return 0;
+
                /* TCS and TES load inputs directly from LDS or offchip
                 * memory, so indirect indexing is always supported.
                 * PS has to support indirect indexing, because we can't