4 files changed, 21 insertions, 2 deletions
diff --git a/src/gallium/drivers/radeonsi/si_blit.c b/src/gallium/drivers/radeonsi/si_blit.c
index 87c8fa9c634..4e77d74a79f 100644
--- a/src/gallium/drivers/radeonsi/si_blit.c
+++ b/src/gallium/drivers/radeonsi/si_blit.c
@@ -328,6 +328,9 @@ static void si_clear(struct pipe_context *ctx, unsigned buffers,
 {
 	struct si_context *sctx = (struct si_context *)ctx;
 	struct pipe_framebuffer_state *fb = &sctx->framebuffer.state;
+	struct pipe_surface *zsbuf = fb->zsbuf;
+	struct r600_texture *zstex =
+		zsbuf ? (struct r600_texture*)zsbuf->texture : NULL;
 
 	if (buffers & PIPE_CLEAR_COLOR) {
 		evergreen_do_fast_color_clear(&sctx->b, fb, &sctx->framebuffer.atom,
@@ -354,11 +357,23 @@ static void si_clear(struct pipe_context *ctx, unsigned buffers,
 		}
 	}
 
+	if (buffers & PIPE_CLEAR_DEPTH &&
+	    zstex && zstex->htile_buffer &&
+	    zsbuf->u.tex.level == 0 &&
+	    zsbuf->u.tex.first_layer == 0 &&
+	    zsbuf->u.tex.last_layer == util_max_layer(&zstex->resource.b.b, 0)) {
+		zstex->depth_clear_value = depth;
+		sctx->framebuffer.atom.dirty = true; /* updates DB_DEPTH_CLEAR */
+		sctx->db_depth_clear = true;
+	}
+
 	si_blitter_begin(ctx, SI_CLEAR);
 	util_blitter_clear(sctx->blitter, fb->width, fb->height,
 			   util_framebuffer_get_num_layers(fb),
 			   buffers, color, depth, stencil);
 	si_blitter_end(ctx);
+
+	sctx->db_depth_clear = false;
 }
 
 static void si_clear_render_target(struct pipe_context *ctx,
diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index c4f38001c75..0a79983a49a 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -164,6 +164,7 @@ struct si_context {
 	bool dbcb_stencil_copy_enabled;
 	unsigned dbcb_copy_sample;
 	bool db_inplace_flush_enabled;
+	bool db_depth_clear;
 };
 
 /* si_blit.c */
diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c
index cbb29a91532..9edc23fa1fd 100644
--- a/src/gallium/drivers/radeonsi/si_state.c
+++ b/src/gallium/drivers/radeonsi/si_state.c
@@ -1928,7 +1928,7 @@ static void si_set_framebuffer_state(struct pipe_context *ctx,
 	si_update_fb_blend_state(sctx);
 
 	sctx->framebuffer.atom.num_dw = state->nr_cbufs*15 + (8 - state->nr_cbufs)*3;
-	sctx->framebuffer.atom.num_dw += state->zsbuf ? 23 : 4;
+	sctx->framebuffer.atom.num_dw += state->zsbuf ? 26 : 4;
 	sctx->framebuffer.atom.num_dw += 3; /* WINDOW_SCISSOR_BR */
 	sctx->framebuffer.atom.num_dw += 18; /* MSAA sample locations */
 	sctx->framebuffer.atom.dirty = true;
@@ -2046,6 +2046,7 @@ static void si_emit_framebuffer_state(struct si_context *sctx, struct r600_atom
 		radeon_emit(cs, zb->db_depth_slice);	/* R_02805C_DB_DEPTH_SLICE */
 
 		r600_write_context_reg(cs, R_028ABC_DB_HTILE_SURFACE, zb->db_htile_surface);
+		r600_write_context_reg(cs, R_02802C_DB_DEPTH_CLEAR, fui(rtex->depth_clear_value));
 		r600_write_context_reg(cs, R_028B78_PA_SU_POLY_OFFSET_DB_FMT_CNTL,
 				       zb->pa_su_poly_offset_db_fmt_cntl);
 	} else {
@@ -3090,7 +3091,6 @@ void si_init_config(struct si_context *sctx)
 	si_pm4_set_reg(pm4, R_028020_DB_DEPTH_BOUNDS_MIN, 0x00000000);
 	si_pm4_set_reg(pm4, R_028024_DB_DEPTH_BOUNDS_MAX, 0x00000000);
 	si_pm4_set_reg(pm4, R_028028_DB_STENCIL_CLEAR, 0x00000000);
-	si_pm4_set_reg(pm4, R_02802C_DB_DEPTH_CLEAR, 0x3F800000);
 	si_pm4_set_reg(pm4, R_028AC0_DB_SRESULTS_COMPARE_STATE0, 0x0);
 	si_pm4_set_reg(pm4, R_028AC4_DB_SRESULTS_COMPARE_STATE1, 0x0);
 	si_pm4_set_reg(pm4, R_028AC8_DB_PRELOAD_CONTROL, 0x0);
diff --git a/src/gallium/drivers/radeonsi/si_state_draw.c b/src/gallium/drivers/radeonsi/si_state_draw.c
index eb5869ccc68..4fb205a04b8 100644
--- a/src/gallium/drivers/radeonsi/si_state_draw.c
+++ b/src/gallium/drivers/radeonsi/si_state_draw.c
@@ -751,6 +751,9 @@ static void si_state_draw(struct si_context *sctx,
 		si_pm4_set_reg(pm4, R_028000_DB_RENDER_CONTROL,
 			       S_028000_DEPTH_COMPRESS_DISABLE(1) |
 			       S_028000_STENCIL_COMPRESS_DISABLE(1));
+	} else if (sctx->db_depth_clear) {
+		si_pm4_set_reg(pm4, R_028000_DB_RENDER_CONTROL,
+			       S_028000_DEPTH_CLEAR_ENABLE(1));
 	} else {
 		si_pm4_set_reg(pm4, R_028000_DB_RENDER_CONTROL, 0);
 	}