[Mesa-dev] [PATCH 05/15] radeonsi/gfx9: don't use GS scenario A for VS writing ViewportIndex

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

Vulkan doesn't do it anymore.
---
 src/gallium/drivers/radeonsi/si_state_shaders.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/src/gallium/drivers/radeonsi/si_state_shaders.c b/src/gallium/drivers/radeonsi/si_state_shaders.c
index fd9828f..66cd902 100644
--- a/src/gallium/drivers/radeonsi/si_state_shaders.c
+++ b/src/gallium/drivers/radeonsi/si_state_shaders.c
@@ -850,28 +850,24 @@ static void si_shader_vs(struct si_screen *sscreen, struct si_shader *shader,
 		return;
 
 	/* We always write VGT_GS_MODE in the VS state, because every switch
 	 * between different shader pipelines involving a different GS or no
 	 * GS at all involves a switch of the VS (different GS use different
 	 * copy shaders). On the other hand, when the API switches from a GS to
 	 * no GS and then back to the same GS used originally, the GS state is
 	 * not sent again.
 	 */
 	if (!gs) {
-		unsigned mode = 0;
+		unsigned mode = V_028A40_GS_OFF;
 
-		/* PrimID needs GS scenario A.
-		 * GFX9 also needs it when ViewportIndex is enabled.
-		 */
-		if (enable_prim_id ||
-		    (sscreen->b.chip_class >= GFX9 &&
-		     shader->selector->info.writes_viewport_index))
+		/* PrimID needs GS scenario A. */
+		if (enable_prim_id)
 			mode = V_028A40_GS_SCENARIO_A;
 
 		si_pm4_set_reg(pm4, R_028A40_VGT_GS_MODE, S_028A40_MODE(mode));
 		si_pm4_set_reg(pm4, R_028A84_VGT_PRIMITIVEID_EN, enable_prim_id);
 	} else {
 		si_pm4_set_reg(pm4, R_028A40_VGT_GS_MODE, si_vgt_gs_mode(gs));
 		si_pm4_set_reg(pm4, R_028A84_VGT_PRIMITIVEID_EN, 0);
 	}
 
 	va = shader->bo->gpu_address;
-- 
2.7.4