diff --git a/src/gallium/drivers/radeonsi/si_state_shaders.cpp b/src/gallium/drivers/radeonsi/si_state_shaders.cpp
index 13cc047872b..75cadf05014 100644
--- a/src/gallium/drivers/radeonsi/si_state_shaders.cpp
+++ b/src/gallium/drivers/radeonsi/si_state_shaders.cpp
@@ -1990,12 +1990,15 @@ static void si_shader_ps(struct si_screen *sscreen, struct si_shader *shader)
 {
    struct si_shader_info *info = &shader->selector->info;
    const unsigned input_ena = shader->config.spi_ps_input_ena;
+   /* At least one of these is required to be set. */
+   ASSERTED unsigned num_required_vgpr_inputs =
+      G_0286CC_PERSP_SAMPLE_ENA(input_ena) + G_0286CC_PERSP_CENTER_ENA(input_ena) +
+      G_0286CC_PERSP_CENTROID_ENA(input_ena) + G_0286CC_PERSP_PULL_MODEL_ENA(input_ena) +
+      G_0286CC_LINEAR_SAMPLE_ENA(input_ena) + G_0286CC_LINEAR_CENTER_ENA(input_ena) +
+      G_0286CC_LINEAR_CENTROID_ENA(input_ena) + G_0286CC_LINE_STIPPLE_TEX_ENA(input_ena);
 
    /* we need to enable at least one of them, otherwise we hang the GPU */
-   assert(G_0286CC_PERSP_SAMPLE_ENA(input_ena) || G_0286CC_PERSP_CENTER_ENA(input_ena) ||
-          G_0286CC_PERSP_CENTROID_ENA(input_ena) || G_0286CC_PERSP_PULL_MODEL_ENA(input_ena) ||
-          G_0286CC_LINEAR_SAMPLE_ENA(input_ena) || G_0286CC_LINEAR_CENTER_ENA(input_ena) ||
-          G_0286CC_LINEAR_CENTROID_ENA(input_ena) || G_0286CC_LINE_STIPPLE_TEX_ENA(input_ena));
+   assert(num_required_vgpr_inputs > 0);
    /* POS_W_FLOAT_ENA requires one of the perspective weights. */
    assert(!G_0286CC_POS_W_FLOAT_ENA(input_ena) || G_0286CC_PERSP_SAMPLE_ENA(input_ena) ||
           G_0286CC_PERSP_CENTER_ENA(input_ena) || G_0286CC_PERSP_CENTROID_ENA(input_ena) ||
@@ -2006,13 +2009,13 @@ static void si_shader_ps(struct si_screen *sscreen, struct si_shader *shader)
           (G_0286CC_PERSP_CENTER_ENA(input_ena) && G_0286CC_PERSP_CENTROID_ENA(input_ena)));
    assert(!shader->key.ps.part.prolog.bc_optimize_for_linear ||
           (G_0286CC_LINEAR_CENTER_ENA(input_ena) && G_0286CC_LINEAR_CENTROID_ENA(input_ena)));
-   assert(!shader->key.ps.part.prolog.force_persp_center_interp ||
+   assert(!shader->key.ps.part.prolog.force_persp_center_interp || num_required_vgpr_inputs == 1 ||
           (!G_0286CC_PERSP_SAMPLE_ENA(input_ena) && !G_0286CC_PERSP_CENTROID_ENA(input_ena)));
-   assert(!shader->key.ps.part.prolog.force_linear_center_interp ||
+   assert(!shader->key.ps.part.prolog.force_linear_center_interp || num_required_vgpr_inputs == 1 ||
           (!G_0286CC_LINEAR_SAMPLE_ENA(input_ena) && !G_0286CC_LINEAR_CENTROID_ENA(input_ena)));
-   assert(!shader->key.ps.part.prolog.force_persp_sample_interp ||
+   assert(!shader->key.ps.part.prolog.force_persp_sample_interp || num_required_vgpr_inputs == 1 ||
           (!G_0286CC_PERSP_CENTER_ENA(input_ena) && !G_0286CC_PERSP_CENTROID_ENA(input_ena)));
-   assert(!shader->key.ps.part.prolog.force_linear_sample_interp ||
+   assert(!shader->key.ps.part.prolog.force_linear_sample_interp || num_required_vgpr_inputs == 1 ||
           (!G_0286CC_LINEAR_CENTER_ENA(input_ena) && !G_0286CC_LINEAR_CENTROID_ENA(input_ena)));
 
    /* color_two_side always enables FRONT_FACE. Since st/mesa disables two-side colors if the back