diff --git a/src/gallium/drivers/radeonsi/si_pipe.h b/src/gallium/drivers/radeonsi/si_pipe.h
index 847281ee2fc..42cbecbf13e 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.h
+++ b/src/gallium/drivers/radeonsi/si_pipe.h
@@ -167,6 +167,7 @@ struct si_framebuffer {
 	unsigned			nr_samples;
 	unsigned			log_samples;
 	unsigned			compressed_cb_mask;
+	unsigned			colorbuf_enabled_4bit;
 	unsigned			spi_shader_col_format;
 	unsigned			spi_shader_col_format_alpha;
 	unsigned			spi_shader_col_format_blend;
diff --git a/src/gallium/drivers/radeonsi/si_state.c b/src/gallium/drivers/radeonsi/si_state.c
index b3299a95b78..b4683c52dd0 100644
--- a/src/gallium/drivers/radeonsi/si_state.c
+++ b/src/gallium/drivers/radeonsi/si_state.c
@@ -2360,6 +2360,7 @@ static void si_set_framebuffer_state(struct pipe_context *ctx,
 	si_dec_framebuffer_counters(&sctx->framebuffer.state);
 	util_copy_framebuffer_state(&sctx->framebuffer.state, state);
 
+	sctx->framebuffer.colorbuf_enabled_4bit = 0;
 	sctx->framebuffer.spi_shader_col_format = 0;
 	sctx->framebuffer.spi_shader_col_format_alpha = 0;
 	sctx->framebuffer.spi_shader_col_format_blend = 0;
@@ -2382,6 +2383,7 @@ static void si_set_framebuffer_state(struct pipe_context *ctx,
 			si_initialize_color_surface(sctx, surf);
 		}
 
+		sctx->framebuffer.colorbuf_enabled_4bit |= 0xf << (i * 4);
 		sctx->framebuffer.spi_shader_col_format |=
 			surf->spi_shader_col_format << (i * 4);
 		sctx->framebuffer.spi_shader_col_format_alpha |=
diff --git a/src/gallium/drivers/radeonsi/si_state_shaders.c b/src/gallium/drivers/radeonsi/si_state_shaders.c
index 7834f8711b6..cd4b33918ee 100644
--- a/src/gallium/drivers/radeonsi/si_state_shaders.c
+++ b/src/gallium/drivers/radeonsi/si_state_shaders.c
@@ -867,7 +867,24 @@ static void si_shader_selector_key_hw_vs(struct si_context *sctx,
 		!vs->info.culldist_writemask;
 
 	/* Find out if PS is disabled. */
-	bool ps_disabled = ps == NULL;
+	bool ps_disabled = true;
+	if (ps) {
+		bool ps_modifies_zs = ps->info.uses_kill ||
+				      ps->info.writes_z ||
+				      ps->info.writes_stencil ||
+				      ps->info.writes_samplemask ||
+				      si_get_alpha_test_func(sctx) != PIPE_FUNC_ALWAYS;
+
+		unsigned ps_colormask = sctx->framebuffer.colorbuf_enabled_4bit &
+					sctx->queued.named.blend->cb_target_mask;
+		if (!ps->info.properties[TGSI_PROPERTY_FS_COLOR0_WRITES_ALL_CBUFS])
+			ps_colormask &= ps->colors_written_4bit;
+
+		ps_disabled = sctx->queued.named.rasterizer->rasterizer_discard ||
+			      (!ps_colormask &&
+			       !ps_modifies_zs &&
+			       !ps->info.writes_memory);
+	}
 
 	/* Find out which VS outputs aren't used by the PS. */
 	uint64_t outputs_written = vs->outputs_written;