drm/nouveau: do not unpin in nouveau_gem_object_del

This should no longer be required, and is harmful for framebuffer pinning.
Also add a warning if unpin causes the pin count to drop below 0.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

2 files changed, 5 insertions, 8 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index 85fed108d7e4..824a98811de6 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -148,6 +148,7 @@ nouveau_bo_del_ttm(struct ttm_buffer_object *bo)
 
         if (unlikely(nvbo->gem))
                 DRM_ERROR("bo %p still attached to GEM object\n", bo);
+        WARN_ON(nvbo->pin_refcnt > 0);
         nv10_bo_put_tile_region(dev, nvbo->tile, NULL);
         kfree(nvbo);
 }
@@ -340,13 +341,15 @@ nouveau_bo_unpin(struct nouveau_bo *nvbo)
 {
         struct nouveau_drm *drm = nouveau_bdev(nvbo->bo.bdev);
         struct ttm_buffer_object *bo = &nvbo->bo;
-        int ret;
+        int ret, ref;
 
         ret = ttm_bo_reserve(bo, false, false, false, 0);
         if (ret)
                 return ret;
 
-        if (--nvbo->pin_refcnt)
+        ref = --nvbo->pin_refcnt;
+        WARN_ON_ONCE(ref < 0);
+        if (ref)
                 goto out;
 
         nouveau_bo_placement_set(nvbo, bo->mem.placement, 0);
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index e72d09c068a8..830cb7bad922 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -50,12 +50,6 @@ nouveau_gem_object_del(struct drm_gem_object *gem)
                 return;
         nvbo->gem = NULL;
 
-        /* Lockdep hates you for doing reserve with gem object lock held */
-        if (WARN_ON_ONCE(nvbo->pin_refcnt)) {
-                nvbo->pin_refcnt = 1;
-                nouveau_bo_unpin(nvbo);
-        }
-
         if (gem->import_attach)
                 drm_prime_gem_destroy(gem, nvbo->bo.sg);