radeonsi: fix a hang with instancing on Hawaii

This fixes "piglit/bin/arb_transform_feedback2-draw-auto instanced".

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

diff --git a/src/gallium/drivers/radeonsi/si_state_draw.c b/src/gallium/drivers/radeonsi/si_state_draw.c
index f829d0363a4c04fc58c5a22485f8754d6df3009d..1816540fa007d953d513c6ef3485e6da68b3b757 100644 (file)
--- a/src/gallium/drivers/radeonsi/si_state_draw.c
+++ b/src/gallium/drivers/radeonsi/si_state_draw.c
@@ -33,6 +33,7 @@
 #include "util/u_format.h"
 #include "util/u_index_modify.h"
 #include "util/u_memory.h"
+#include "util/u_prim.h"
 #include "util/u_upload_mgr.h"
 
 /*
@@ -408,6 +409,19 @@ static bool si_update_draw_info_state(struct si_context *sctx,
                                        (rs ? rs->line_stipple_enable : false);
                /* If the WD switch is false, the IA switch must be false too. */
                bool ia_switch_on_eop = wd_switch_on_eop;
+               unsigned primgroup_size = 64;
+
+               /* Hawaii hangs if instancing is enabled and each instance
+                * is smaller than a prim group and WD_SWITCH_ON_EOP is 0.
+                * We don't know that for indirect drawing, so treat it as
+                * always problematic. */
+               if (sctx->b.family == CHIP_HAWAII &&
+                   (info->indirect ||
+                    (info->instance_count > 1 &&
+                     u_prims_for_vertices(info->mode, info->count) < primgroup_size))) {
+                       wd_switch_on_eop = true;
+                       ia_switch_on_eop = true;
+               }
 
                si_pm4_set_reg(pm4, R_028B74_VGT_DISPATCH_DRAW_INDEX,
                               ib->index_size == 4 ? 0xFC000000 : 0xFC00);
@@ -417,7 +431,7 @@ static bool si_update_draw_info_state(struct si_context *sctx,
                si_pm4_cmd_add(pm4, /* IA_MULTI_VGT_PARAM */
                               S_028AA8_SWITCH_ON_EOP(ia_switch_on_eop) |
                               S_028AA8_PARTIAL_VS_WAVE_ON(1) |
-                              S_028AA8_PRIMGROUP_SIZE(63) |
+                              S_028AA8_PRIMGROUP_SIZE(primgroup_size - 1) |
                               S_028AA8_WD_SWITCH_ON_EOP(wd_switch_on_eop));
                si_pm4_cmd_add(pm4, 0); /* VGT_LS_HS_CONFIG */
                si_pm4_cmd_end(pm4, false);