[Mesa-dev] [PATCH 1/5] r600g: use invalid DB hardware formats to disable depth/stencil

[Marek Olšák]

---
 src/gallium/drivers/r600/evergreen_state.c |   17 +++++++++++++++--
 src/gallium/drivers/r600/evergreend.h      |    2 ++
 src/gallium/drivers/r600/r600_state.c      |    6 ++++++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/gallium/drivers/r600/evergreen_state.c b/src/gallium/drivers/r600/evergreen_state.c
index 3f4ee8e..98dbb2f 100644
--- a/src/gallium/drivers/r600/evergreen_state.c
+++ b/src/gallium/drivers/r600/evergreen_state.c
@@ -1434,10 +1434,15 @@ static void evergreen_init_depth_surface(struct r600_context *rctx,
 		stencil_offset >>= 8;
 
 		surf->db_stencil_base = stencil_offset;
-		surf->db_stencil_info = 1 | S_028044_TILE_SPLIT(stile_split);
+		surf->db_stencil_info = S_028044_FORMAT(V_028044_STENCIL_8) |
+					S_028044_TILE_SPLIT(stile_split);
 	} else {
 		surf->db_stencil_base = offset;
-		surf->db_stencil_info = 1;
+		/* DRM 2.6.18 allows the INVALID format to disable stencil.
+		 * Older kernels are out of luck. */
+		surf->db_stencil_info = rctx->screen->info.drm_minor >= 18 ?
+					S_028044_FORMAT(V_028044_STENCIL_INVALID) :
+					S_028044_FORMAT(V_028044_STENCIL_8);
 	}
 
 	surf->depth_initialized = true;
@@ -1575,6 +1580,8 @@ static void evergreen_set_framebuffer_state(struct pipe_context *ctx,
 		rctx->framebuffer.atom.num_dw += 21;
 		if (rctx->keep_tiling_flags)
 			rctx->framebuffer.atom.num_dw += 2;
+	} else if (rctx->screen->info.drm_minor >= 18) {
+		rctx->framebuffer.atom.num_dw += 4;
 	}
 
 	r600_atom_dirty(rctx, &rctx->framebuffer.atom);
@@ -1903,6 +1910,12 @@ static void evergreen_emit_framebuffer_state(struct r600_context *rctx, struct r
 
 		r600_write_value(cs, PKT3(PKT3_NOP, 0, 0)); /* R_028054_DB_STENCIL_WRITE_BASE */
 		r600_write_value(cs, reloc);
+	} else if (rctx->screen->info.drm_minor >= 18) {
+		/* DRM 2.6.18 allows the INVALID format to disable depth/stencil.
+		 * Older kernels are out of luck. */
+		r600_write_context_reg_seq(cs, R_028040_DB_Z_INFO, 2);
+		r600_write_value(cs, S_028040_FORMAT(V_028040_Z_INVALID)); /* R_028040_DB_Z_INFO */
+		r600_write_value(cs, S_028044_FORMAT(V_028044_STENCIL_INVALID)); /* R_028044_DB_STENCIL_INFO */
 	}
 
 	/* Framebuffer dimensions. */
diff --git a/src/gallium/drivers/r600/evergreend.h b/src/gallium/drivers/r600/evergreend.h
index cb89199..3dff6f9 100644
--- a/src/gallium/drivers/r600/evergreend.h
+++ b/src/gallium/drivers/r600/evergreend.h
@@ -567,6 +567,8 @@
 
 #define R_028044_DB_STENCIL_INFO                     0x028044
 #define   S_028044_FORMAT(x)                           (((x) & 0x1) << 0)
+#define     V_028044_STENCIL_INVALID			0
+#define     V_028044_STENCIL_8				1
 #define   G_028044_FORMAT(x)                           (((x) >> 0) & 0x1)
 #define   C_028044_FORMAT                              0xFFFFFFFE
 #define   S_028044_TILE_SPLIT(x)                       (((x) & 0x7) << 8)
diff --git a/src/gallium/drivers/r600/r600_state.c b/src/gallium/drivers/r600/r600_state.c
index 17ab259..1b7869c 100644
--- a/src/gallium/drivers/r600/r600_state.c
+++ b/src/gallium/drivers/r600/r600_state.c
@@ -1552,6 +1552,8 @@ static void r600_set_framebuffer_state(struct pipe_context *ctx,
 	}
 	if (rctx->framebuffer.state.zsbuf) {
 		rctx->framebuffer.atom.num_dw += 13;
+	} else if (rctx->screen->info.drm_minor >= 18) {
+		rctx->framebuffer.atom.num_dw += 3;
 	}
 	if (rctx->family > CHIP_R600 && rctx->family < CHIP_RV770) {
 		rctx->framebuffer.atom.num_dw += 2;
@@ -1753,6 +1755,10 @@ static void r600_emit_framebuffer_state(struct r600_context *rctx, struct r600_a
 		r600_write_context_reg(cs, R_028D34_DB_PREFETCH_LIMIT, surf->db_prefetch_limit);
 
 		sbu |= SURFACE_BASE_UPDATE_DEPTH;
+	} else if (rctx->screen->info.drm_minor >= 18) {
+		/* DRM 2.6.18 allows the INVALID format to disable depth/stencil.
+		 * Older kernels are out of luck. */
+		r600_write_context_reg(cs, R_028010_DB_DEPTH_INFO, S_028010_FORMAT(V_028010_DEPTH_INVALID));
 	}
 
 	/* SURFACE_BASE_UPDATE */
-- 
1.7.9.5