radeonsi: don't set the CB clear color registers for 0/1 clear colors on Raven2

and add has_dcc_constant_encode.

4 files changed, 11 insertions, 3 deletions

diff --git a/src/gallium/drivers/radeonsi/si_clear.c b/src/gallium/drivers/radeonsi/si_clear.c
index 3f5375337a1..9026f61dc0a 100644
--- a/src/gallium/drivers/radeonsi/si_clear.c
+++ b/src/gallium/drivers/radeonsi/si_clear.c
@@ -212,8 +212,8 @@ static bool vi_get_fast_clear_parameters(enum pipe_format base_format,
 	}
 
 	/* This doesn't need ELIMINATE_FAST_CLEAR.
-	 * CB uses both the DCC clear codes and the CB clear color registers,
-	 * so they must match.
+	 * On chips predating Raven2, the DCC clear codes and the CB clear
+	 * color registers must match.
 	 */
 	*eliminate_needed = false;
 
@@ -548,6 +548,12 @@ static void si_do_fast_color_clear(struct si_context *sctx,
 
 		*buffers &= ~clear_bit;
 
+		/* Chips with DCC constant encoding don't need to set the clear
+		 * color registers for DCC clear values 0 and 1.
+		 */
+		if (sctx->screen->has_dcc_constant_encode && !eliminate_needed)
+			continue;
+
 		if (si_set_clear_color(tex, fb->cbufs[i]->format, color)) {
 			sctx->framebuffer.dirty_cbufs |= 1 << i;
 			si_mark_atom_dirty(sctx, &sctx->atoms.s.framebuffer);
diff --git a/src/gallium/drivers/radeonsi/si_pipe.c b/src/gallium/drivers/radeonsi/si_pipe.c
index 490a3714836..ba406bee922 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.c
+++ b/src/gallium/drivers/radeonsi/si_pipe.c
@@ -1029,6 +1029,7 @@ struct pipe_screen *radeonsi_screen_create(struct radeon_winsys *ws,
 					   sscreen->info.family == CHIP_RAVEN;
 	sscreen->has_ls_vgpr_init_bug = sscreen->info.family == CHIP_VEGA10 ||
 					sscreen->info.family == CHIP_RAVEN;
+	sscreen->has_dcc_constant_encode = sscreen->info.family == CHIP_RAVEN2;
 
 	if (sscreen->debug_flags & DBG(DPBB)) {
 		sscreen->dpbb_allowed = true;
diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index 0807c8ddacc..023e0f0a0f9 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -445,6 +445,7 @@ struct si_screen {
 	bool				clear_db_cache_before_clear;
 	bool				has_msaa_sample_loc_bug;
 	bool				has_ls_vgpr_init_bug;
+	bool				has_dcc_constant_encode;
 	bool				dpbb_allowed;
 	bool				dfsm_allowed;
 	bool				llvm_has_working_vgpr_indexing;
diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c
index 0293bdfa791..e3b45fa6ea7 100644
--- a/src/gallium/drivers/radeonsi/si_state.c
+++ b/src/gallium/drivers/radeonsi/si_state.c
@@ -121,7 +121,7 @@ static void si_emit_cb_render_state(struct si_context *sctx)
 				S_028424_OVERWRITE_COMBINER_MRT_SHARING_DISABLE(1) |
 				S_028424_OVERWRITE_COMBINER_WATERMARK(watermark) |
 				S_028424_OVERWRITE_COMBINER_DISABLE(oc_disable) |
-				S_028424_DISABLE_CONSTANT_ENCODE_REG(sctx->family == CHIP_RAVEN2));
+				S_028424_DISABLE_CONSTANT_ENCODE_REG(sctx->screen->has_dcc_constant_encode));
 	}
 
 	/* RB+ register settings. */