[Mesa-dev] [PATCH 12/12] radeonsi: allow MSAA resolving into a texture that has DCC enabled

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

Since DCC is enabled almost everywhere now, it's important not to disable
this fast path.
---
 src/gallium/drivers/radeonsi/si_blit.c  | 15 +++++++++++++--
 src/gallium/drivers/radeonsi/si_state.c | 12 ++++++++++--
 2 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/src/gallium/drivers/radeonsi/si_blit.c b/src/gallium/drivers/radeonsi/si_blit.c
index 3f45256..5c7b318 100644
--- a/src/gallium/drivers/radeonsi/si_blit.c
+++ b/src/gallium/drivers/radeonsi/si_blit.c
@@ -902,8 +902,19 @@ static bool do_hardware_msaa_resolve(struct pipe_context *ctx,
 	    info->src.box.height == dst_height &&
 	    info->src.box.depth == 1 &&
 	    dst->surface.level[info->dst.level].mode >= RADEON_SURF_MODE_1D &&
-	    (!dst->cmask.size || !dst->dirty_level_mask) && /* dst cannot be fast-cleared */
-	    !dst->dcc_offset) {
+	    (!dst->cmask.size || !dst->dirty_level_mask)) { /* dst cannot be fast-cleared */
+		/* Resolving into a surface with DCC is unsupported. Since
+		 * it's being overwritten anyway, clear it to uncompressed.
+		 * This is still the fastest codepath even with this clear.
+		 */
+		if (dst->dcc_offset &&
+		    dst->surface.level[info->dst.level].dcc_enabled) {
+			vi_dcc_clear_level(&sctx->b, dst, info->dst.level,
+					   0xFFFFFFFF);
+			dst->dirty_level_mask &= ~(1 << info->dst.level);
+		}
+
+		/* Resolve directly from src to dst. */
 		si_blitter_begin(ctx, SI_COLOR_RESOLVE |
 				 (info->render_condition_enable ? 0 : SI_DISABLE_RENDER_COND));
 		util_blitter_custom_resolve_color(sctx->blitter,
diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c
index 39f5799..2e8fc7f 100644
--- a/src/gallium/drivers/radeonsi/si_state.c
+++ b/src/gallium/drivers/radeonsi/si_state.c
@@ -2445,8 +2445,16 @@ static void si_emit_framebuffer_state(struct si_context *sctx, struct r600_atom
 		}
 
 		cb_color_info = cb->cb_color_info | tex->cb_color_info;
-		if (tex->dcc_offset && cb->level_info->dcc_enabled)
-			cb_color_info |= S_028C70_DCC_ENABLE(1);
+
+		if (tex->dcc_offset && cb->level_info->dcc_enabled) {
+			bool is_msaa_resolve_dst = state->cbufs[0] &&
+						   state->cbufs[0]->texture->nr_samples > 1 &&
+						   state->cbufs[1] == &cb->base &&
+						   state->cbufs[1]->texture->nr_samples <= 1;
+
+			if (!is_msaa_resolve_dst)
+				cb_color_info |= S_028C70_DCC_ENABLE(1);
+		}
 
 		radeon_set_context_reg_seq(cs, R_028C60_CB_COLOR0_BASE + i * 0x3C,
 					   sctx->b.chip_class >= VI ? 14 : 13);
-- 
2.7.4