[Mesa-dev] [PATCH] radeonsi/gfx9: fix a hang with an empty first IB

[Marek Olšák]

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

This packet causes the no-op IB detection to fail, so the IB is always
submitted. Also fix the no-op IB detection by moving the begin call.

Cc: 18.0 <mesa-stable at lists.freedesktop.org>
---
 src/gallium/drivers/radeonsi/si_pipe.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/gallium/drivers/radeonsi/si_pipe.c b/src/gallium/drivers/radeonsi/si_pipe.c
index d044b191b71..ac16aae3078 100644
--- a/src/gallium/drivers/radeonsi/si_pipe.c
+++ b/src/gallium/drivers/radeonsi/si_pipe.c
@@ -522,38 +522,37 @@ static struct pipe_context *si_create_context(struct pipe_screen *screen,
 		sctx->b.resource_copy_region = sctx->dma_copy;
 
 	sctx->blitter = util_blitter_create(&sctx->b);
 	if (sctx->blitter == NULL)
 		goto fail;
 	sctx->blitter->draw_rectangle = si_draw_rectangle;
 	sctx->blitter->skip_viewport_restore = true;
 
 	sctx->sample_mask = 0xffff;
 
-	/* these must be last */
-	si_begin_new_gfx_cs(sctx);
-
 	if (sctx->chip_class >= GFX9) {
 		sctx->wait_mem_scratch = r600_resource(
 			pipe_buffer_create(screen, 0, PIPE_USAGE_DEFAULT, 4));
 		if (!sctx->wait_mem_scratch)
 			goto fail;
 
 		/* Initialize the memory. */
 		struct radeon_winsys_cs *cs = sctx->gfx_cs;
 		radeon_emit(cs, PKT3(PKT3_WRITE_DATA, 3, 0));
 		radeon_emit(cs, S_370_DST_SEL(V_370_MEMORY_SYNC) |
 			    S_370_WR_CONFIRM(1) |
 			    S_370_ENGINE_SEL(V_370_ME));
 		radeon_emit(cs, sctx->wait_mem_scratch->gpu_address);
 		radeon_emit(cs, sctx->wait_mem_scratch->gpu_address >> 32);
 		radeon_emit(cs, sctx->wait_mem_number);
+		radeon_add_to_buffer_list(sctx, cs, sctx->wait_mem_scratch,
+					  RADEON_USAGE_WRITE, RADEON_PRIO_FENCE);
 	}
 
 	/* CIK cannot unbind a constant buffer (S_BUFFER_LOAD doesn't skip loads
 	 * if NUM_RECORDS == 0). We need to use a dummy buffer instead. */
 	if (sctx->chip_class == CIK) {
 		sctx->null_const_buf.buffer =
 			pipe_aligned_buffer_create(screen,
 						   SI_RESOURCE_FLAG_32BIT,
 						   PIPE_USAGE_DEFAULT, 16,
 						   sctx->screen->info.tcc_cache_line_size);
@@ -612,20 +611,22 @@ static struct pipe_context *si_create_context(struct pipe_screen *screen,
 						    _mesa_key_pointer_equal);
 	sctx->img_handles = _mesa_hash_table_create(NULL, _mesa_hash_pointer,
 						    _mesa_key_pointer_equal);
 
 	util_dynarray_init(&sctx->resident_tex_handles, NULL);
 	util_dynarray_init(&sctx->resident_img_handles, NULL);
 	util_dynarray_init(&sctx->resident_tex_needs_color_decompress, NULL);
 	util_dynarray_init(&sctx->resident_img_needs_color_decompress, NULL);
 	util_dynarray_init(&sctx->resident_tex_needs_depth_decompress, NULL);
 
+	/* this must be last */
+	si_begin_new_gfx_cs(sctx);
 	return &sctx->b;
 fail:
 	fprintf(stderr, "radeonsi: Failed to create a context.\n");
 	si_destroy_context(&sctx->b);
 	return NULL;
 }
 
 static struct pipe_context *si_pipe_create_context(struct pipe_screen *screen,
 						   void *priv, unsigned flags)
 {
-- 
2.17.0