From 6e786d9e657dc3a0cb659dbf68a11fe75e554d8f Mon Sep 17 00:00:00 2001
From: Thierry Reding <treding@nvidia.com>
Date: Wed, 6 Oct 2021 22:47:17 +0200
Subject: [PATCH 2/6] tegra: Use private reference count for resources

With the recent addition of the shortcuts aiming to avoid atomic
operations, the reference count on resources can become unbalanced
in the Tegra driver since they are wrapped and then proxied to the
Nouveau driver.

Fix this by keeping a private reference count.

Fixes: 7688b8ae9802 ("st/mesa: eliminate all atomic ops when setting vertex buffers")
Tested-by: Karol Herbst <kherbst@redhat.com>
---
 src/gallium/drivers/tegra/tegra_resource.h | 1 +
 src/gallium/drivers/tegra/tegra_screen.c   | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/src/gallium/drivers/tegra/tegra_resource.h b/src/gallium/drivers/tegra/tegra_resource.h
index 67507d64590..892afaf5e0f 100644
--- a/src/gallium/drivers/tegra/tegra_resource.h
+++ b/src/gallium/drivers/tegra/tegra_resource.h
@@ -31,6 +31,7 @@ struct winsys_handle;
 struct tegra_resource {
    struct pipe_resource base;
    struct pipe_resource *gpu;
+   unsigned int refcount;
 
    uint64_t modifier;
    uint32_t stride;
diff --git a/src/gallium/drivers/tegra/tegra_screen.c b/src/gallium/drivers/tegra/tegra_screen.c
index 2b108b07908..3c4c36e0c94 100644
--- a/src/gallium/drivers/tegra/tegra_screen.c
+++ b/src/gallium/drivers/tegra/tegra_screen.c
@@ -245,6 +245,10 @@ tegra_screen_resource_create(struct pipe_screen *pscreen,
    pipe_reference_init(&resource->base.reference, 1);
    resource->base.screen = &screen->base;
 
+   /* use private reference count for wrapped resources */
+   resource->gpu->reference.count += 100000000;
+   resource->refcount = 100000000;
+
    return &resource->base;
 
 destroy:
@@ -352,6 +356,8 @@ tegra_screen_resource_destroy(struct pipe_screen *pscreen,
 {
    struct tegra_resource *resource = to_tegra_resource(presource);
 
+   /* adjust private reference count */
+   p_atomic_add(&resource->gpu->reference.count, -resource->refcount);
    pipe_resource_reference(&resource->gpu, NULL);
    free(resource);
 }
-- 
2.31.1