[PATCH 1/2] drm/ttm: fix re-init of global structures

[Christian König]

When a driver unloads without unloading TTM we don't correctly
clear the global structures leading to errors on re-init.

Next step should probably be to remove the global structures and
kobjs all together, but this is tricky since we need to maintain
backward compatibility.

Signed-off-by: Christian König <christian.koe...@amd.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c     | 10 +++++-----
 drivers/gpu/drm/ttm/ttm_memory.c |  5 +++--
 include/drm/ttm/ttm_bo_driver.h  |  1 -
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 41d07faa2eae..2845fceb2fbd 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -49,9 +49,8 @@ static void ttm_bo_global_kobj_release(struct kobject *kobj);
  * ttm_global_mutex - protecting the global BO state
  */
 DEFINE_MUTEX(ttm_global_mutex);
-struct ttm_bo_global ttm_bo_glob = {
-       .use_count = 0
-};
+unsigned ttm_bo_glob_use_count;
+struct ttm_bo_global ttm_bo_glob;
 
 static struct attribute ttm_bo_count = {
        .name = "bo_count",
@@ -1531,12 +1530,13 @@ static void ttm_bo_global_release(void)
        struct ttm_bo_global *glob = &ttm_bo_glob;
 
        mutex_lock(&ttm_global_mutex);
-       if (--glob->use_count > 0)
+       if (--ttm_bo_glob_use_count > 0)
                goto out;
 
        kobject_del(&glob->kobj);
        kobject_put(&glob->kobj);
        ttm_mem_global_release(&ttm_mem_glob);
+       memset(glob, 0, sizeof(*glob));
 out:
        mutex_unlock(&ttm_global_mutex);
 }
@@ -1548,7 +1548,7 @@ static int ttm_bo_global_init(void)
        unsigned i;
 
        mutex_lock(&ttm_global_mutex);
-       if (++glob->use_count > 1)
+       if (++ttm_bo_glob_use_count > 1)
                goto out;
 
        ret = ttm_mem_global_init(&ttm_mem_glob);
diff --git a/drivers/gpu/drm/ttm/ttm_memory.c b/drivers/gpu/drm/ttm/ttm_memory.c
index 699fed9e08ee..8617958b7ae6 100644
--- a/drivers/gpu/drm/ttm/ttm_memory.c
+++ b/drivers/gpu/drm/ttm/ttm_memory.c
@@ -461,8 +461,8 @@ int ttm_mem_global_init(struct ttm_mem_global *glob)
 
 void ttm_mem_global_release(struct ttm_mem_global *glob)
 {
-       unsigned int i;
        struct ttm_mem_zone *zone;
+       unsigned int i;
 
        /* let the page allocator first stop the shrink work. */
        ttm_page_alloc_fini();
@@ -475,9 +475,10 @@ void ttm_mem_global_release(struct ttm_mem_global *glob)
                zone = glob->zones[i];
                kobject_del(&zone->kobj);
                kobject_put(&zone->kobj);
-                       }
+       }
        kobject_del(&glob->kobj);
        kobject_put(&glob->kobj);
+       memset(glob, 0, sizeof(*glob));
 }
 
 static void ttm_check_swapping(struct ttm_mem_global *glob)
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 3db265bf2d4e..c008346c2401 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -420,7 +420,6 @@ extern struct ttm_bo_global {
        /**
         * Protected by ttm_global_mutex.
         */
-       unsigned int use_count;
        struct list_head device_list;
 
        /**
-- 
2.17.1

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