drm/cma-helper: Fix locking in drm_fb_cma_debugfs_show
This function takes two locks, both of them the wrong ones. This
wasn't an oversight from my fb locking rework since both patches
landed in parallel. We really only need fb_lock when walking that
list, since everything we can reach from that is refcounted properly
already.
v2: Drop unused dev spotted by 0day.
Cc: Rob Clark <robdclark@gmail.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
index 5c1aca4..46c4e6e 100644
--- a/drivers/gpu/drm/drm_fb_cma_helper.c
+++ b/drivers/gpu/drm/drm_fb_cma_helper.c
@@ -209,23 +209,11 @@
struct drm_info_node *node = (struct drm_info_node *) m->private;
struct drm_device *dev = node->minor->dev;
struct drm_framebuffer *fb;
- int ret;
- ret = mutex_lock_interruptible(&dev->mode_config.mutex);
- if (ret)
- return ret;
-
- ret = mutex_lock_interruptible(&dev->struct_mutex);
- if (ret) {
- mutex_unlock(&dev->mode_config.mutex);
- return ret;
- }
-
+ mutex_lock(&dev->mode_config.fb_lock);
list_for_each_entry(fb, &dev->mode_config.fb_list, head)
drm_fb_cma_describe(fb, m);
-
- mutex_unlock(&dev->struct_mutex);
- mutex_unlock(&dev->mode_config.mutex);
+ mutex_unlock(&dev->mode_config.fb_lock);
return 0;
}
diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index bd75f30..9edad11 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -381,11 +381,8 @@
struct seq_file *m)
{
struct drm_gem_object *obj = &cma_obj->base;
- struct drm_device *dev = obj->dev;
uint64_t off;
- WARN_ON(!mutex_is_locked(&dev->struct_mutex));
-
off = drm_vma_node_start(&obj->vma_node);
seq_printf(m, "%2d (%2d) %08llx %pad %p %zu",