[Mesa-dev] [PATCH] r600g: fix lockup when hyperz & alpha test are enabled together.

[j.glisse at gmail.com]

From: Jerome Glisse <jglisse at redhat.com>

Seems that alpha test being enabled confuse the GPU on the order in
which it should perform the Z testing. So force the order programmed
throught db shader control.

Signed-off-by: Jerome Glisse <jglisse at redhat.com>
---
 src/gallium/drivers/r600/evergreen_state.c | 5 +++++
 src/gallium/drivers/r600/r600_state.c      | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/src/gallium/drivers/r600/evergreen_state.c b/src/gallium/drivers/r600/evergreen_state.c
index 211c218..a610b69 100644
--- a/src/gallium/drivers/r600/evergreen_state.c
+++ b/src/gallium/drivers/r600/evergreen_state.c
@@ -2251,6 +2251,11 @@ static void evergreen_emit_db_misc_state(struct r600_context *rctx, struct r600_
 	if (rctx->db_state.rsurf && rctx->db_state.rsurf->htile_enabled) {
 		/* FORCE_OFF means HiZ/HiS are determined by DB_SHADER_CONTROL */
 		db_render_override |= S_02800C_FORCE_HIZ_ENABLE(V_02800C_FORCE_OFF);
+		/* This is to fix a lockup when hyperz and alpha test are enabled at
+		 * the same time some how GPU get confuse on which order to pick for
+		 * z test
+		 */
+		db_render_override |= S_02800C_FORCE_SHADER_Z_ORDER(1);
 	} else {
 		db_render_override |= S_02800C_FORCE_HIZ_ENABLE(V_02800C_FORCE_DISABLE);
 	}
diff --git a/src/gallium/drivers/r600/r600_state.c b/src/gallium/drivers/r600/r600_state.c
index 67c4d99..2760f19 100644
--- a/src/gallium/drivers/r600/r600_state.c
+++ b/src/gallium/drivers/r600/r600_state.c
@@ -1966,6 +1966,11 @@ static void r600_emit_db_misc_state(struct r600_context *rctx, struct r600_atom
 	if (rctx->db_state.rsurf && rctx->db_state.rsurf->htile_enabled) {
 		/* FORCE_OFF means HiZ/HiS are determined by DB_SHADER_CONTROL */
 		db_render_override |= S_028D10_FORCE_HIZ_ENABLE(V_028D10_FORCE_OFF);
+		/* This is to fix a lockup when hyperz and alpha test are enabled at
+		 * the same time some how GPU get confuse on which order to pick for
+		 * z test
+		 */
+		db_render_override |= S_028D10_FORCE_SHADER_Z_ORDER(1);
 	} else {
 		db_render_override |= S_028D10_FORCE_HIZ_ENABLE(V_028D10_FORCE_DISABLE);
 	}
-- 
1.7.11.7