From 7edabee06a5622190d59689a64f5e17d1c343cc3 Mon Sep 17 00:00:00 2001
From: Eric Anholt <eric@anholt.net>
Date: Tue, 27 Sep 2016 09:03:13 -0700
Subject: drm/vc4: Fix races when the CS reads from render targets.

With the introduction of bin/render pipelining, the previous job may
not be completed when we start binning the next one.  If the previous
job wrote our VBO, IB, or CS textures, then the binning stage might
get stale or uninitialized results.

Fixes the major rendering failure in glmark2 -b terrain.

Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes: ca26d28bbaa3 ("drm/vc4: improve throughput by pipelining binning and rendering jobs")
Cc: stable@vger.kernel.org
---
 drivers/gpu/drm/vc4/vc4_validate.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

(limited to 'drivers/gpu/drm/vc4/vc4_validate.c')

diff --git a/drivers/gpu/drm/vc4/vc4_validate.c b/drivers/gpu/drm/vc4/vc4_validate.c
index 9ce1d0adf882..26503e307438 100644
--- a/drivers/gpu/drm/vc4/vc4_validate.c
+++ b/drivers/gpu/drm/vc4/vc4_validate.c
@@ -267,6 +267,9 @@ validate_indexed_prim_list(VALIDATE_ARGS)
 	if (!ib)
 		return -EINVAL;
 
+	exec->bin_dep_seqno = max(exec->bin_dep_seqno,
+				  to_vc4_bo(&ib->base)->write_seqno);
+
 	if (offset > ib->base.size ||
 	    (ib->base.size - offset) / index_size < length) {
 		DRM_ERROR("IB access overflow (%d + %d*%d > %zd)\n",
@@ -555,8 +558,7 @@ static bool
 reloc_tex(struct vc4_exec_info *exec,
 	  void *uniform_data_u,
 	  struct vc4_texture_sample_info *sample,
-	  uint32_t texture_handle_index)
-
+	  uint32_t texture_handle_index, bool is_cs)
 {
 	struct drm_gem_cma_object *tex;
 	uint32_t p0 = *(uint32_t *)(uniform_data_u + sample->p_offset[0]);
@@ -714,6 +716,11 @@ reloc_tex(struct vc4_exec_info *exec,
 
 	*validated_p0 = tex->paddr + p0;
 
+	if (is_cs) {
+		exec->bin_dep_seqno = max(exec->bin_dep_seqno,
+					  to_vc4_bo(&tex->base)->write_seqno);
+	}
+
 	return true;
  fail:
 	DRM_INFO("Texture p0 at %d: 0x%08x\n", sample->p_offset[0], p0);
@@ -835,7 +842,8 @@ validate_gl_shader_rec(struct drm_device *dev,
 			if (!reloc_tex(exec,
 				       uniform_data_u,
 				       &validated_shader->texture_samples[tex],
-				       texture_handles_u[tex])) {
+				       texture_handles_u[tex],
+				       i == 2)) {
 				return -EINVAL;
 			}
 		}
@@ -867,6 +875,9 @@ validate_gl_shader_rec(struct drm_device *dev,
 		uint32_t stride = *(uint8_t *)(pkt_u + o + 5);
 		uint32_t max_index;
 
+		exec->bin_dep_seqno = max(exec->bin_dep_seqno,
+					  to_vc4_bo(&vbo->base)->write_seqno);
+
 		if (state->addr & 0x8)
 			stride |= (*(uint32_t *)(pkt_u + 100 + i * 4)) & ~0xff;
 
-- 
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