Mesa (staging/20.1): freedreno: handle case of shadowing current render target

[GitLab Mirror]

Module: Mesa
Branch: staging/20.1
Commit: 8a0446035daed06c2451b34c05886cd2d37e50bf
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=8a0446035daed06c2451b34c05886cd2d37e50bf

Author: Rob Clark <robdclark at chromium.org>
Date:   Fri Aug 21 15:58:37 2020 -0700

freedreno: handle case of shadowing current render target

If you have a sequence where there is a single buffer associated with
the current render target, and then you end up shadowing it on the 3d
pipe (u_blitter), because of how we swap the new shadow and rsc before
the back-blit, you could end up confusing things into thinking that
the blitters framebuffer state is the same as the current framebuffer
state.

Re-organizing the sequence to swap after the blit is complicated when
also having to deal with CPU memcpy blit path, and the batch/rsc
accounting.  So instead just detect this case and flush if we need to.

Fixes:
dEQP-GLES31.functional.stencil_texturing.render.depth24_stencil8_clear
dEQP-GLES31.functional.stencil_texturing.render.depth24_stencil8_draw

Cc: mesa-stable at lists.freedesktop.org
Signed-off-by: Rob Clark <robdclark at chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6434>
(cherry picked from commit 1fa43a4a8ec37aacac4d333a4c72987819188e69)

---

 .gitlab-ci/deqp-freedreno-a630-fails.txt           |  2 --
 .pick_status.json                                  |  2 +-
 src/gallium/drivers/freedreno/freedreno_resource.c | 18 ++++++++++++++++++
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/.gitlab-ci/deqp-freedreno-a630-fails.txt b/.gitlab-ci/deqp-freedreno-a630-fails.txt
index 61478eb1fef..f08204014b9 100644
--- a/.gitlab-ci/deqp-freedreno-a630-fails.txt
+++ b/.gitlab-ci/deqp-freedreno-a630-fails.txt
@@ -1,4 +1,2 @@
 dEQP-GLES2.functional.clipping.triangle_vertex.clip_three.clip_neg_x_neg_z_and_pos_x_pos_z_and_neg_x_neg_y_pos_z
 dEQP-GLES2.functional.clip_control.depth_mode_zero_to_one
-dEQP-GLES31.functional.stencil_texturing.render.depth24_stencil8_clear
-dEQP-GLES31.functional.stencil_texturing.render.depth24_stencil8_draw
diff --git a/.pick_status.json b/.pick_status.json
index 2955a793172..860b37a6ace 100644
--- a/.pick_status.json
+++ b/.pick_status.json
@@ -1111,7 +1111,7 @@
         "description": "freedreno: handle case of shadowing current render target",
         "nominated": true,
         "nomination_type": 0,
-        "resolution": 0,
+        "resolution": 1,
         "master_sha": null,
         "because_sha": null
     },
diff --git a/src/gallium/drivers/freedreno/freedreno_resource.c b/src/gallium/drivers/freedreno/freedreno_resource.c
index c9e408fe908..e6016189edf 100644
--- a/src/gallium/drivers/freedreno/freedreno_resource.c
+++ b/src/gallium/drivers/freedreno/freedreno_resource.c
@@ -216,6 +216,9 @@ do_blit(struct fd_context *ctx, const struct pipe_blit_info *blit, bool fallback
 	}
 }
 
+static void
+flush_resource(struct fd_context *ctx, struct fd_resource *rsc, unsigned usage);
+
 /**
  * @rsc: the resource to shadow
  * @level: the level to discard (if box != NULL, otherwise ignored)
@@ -233,6 +236,21 @@ fd_try_shadow_resource(struct fd_context *ctx, struct fd_resource *rsc,
 	if (prsc->next)
 		return false;
 
+	/* If you have a sequence where there is a single rsc associated
+	 * with the current render target, and then you end up shadowing
+	 * that same rsc on the 3d pipe (u_blitter), because of how we
+	 * swap the new shadow and rsc before the back-blit, you could end
+	 * up confusing things into thinking that u_blitter's framebuffer
+	 * state is the same as the current framebuffer state, which has
+	 * the result of blitting to rsc rather than shadow.
+	 *
+	 * Normally we wouldn't want to unconditionally trigger a flush,
+	 * since that defeats the purpose of shadowing, but this is a
+	 * case where we'd have to flush anyways.
+	 */
+	if (rsc->write_batch == ctx->batch)
+		flush_resource(ctx, rsc, 0);
+
 	/* TODO: somehow munge dimensions and format to copy unsupported
 	 * render target format to something that is supported?
 	 */