drm: Protect dev->filelist with its own mutex
amdgpu gained dev->struct_mutex usage, and that's because it's walking
the dev->filelist list. Protect that list with it's own lock to take
one more step towards getting rid of struct_mutex usage in drivers
once and for all.
While doing the conversion I noticed that 2 debugfs files in i915
completely lacked appropriate locking. Fix that up too.
v2: don't forget to switch to drm_gem_object_unreference_unlocked.
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1461691808-12414-9-git-send-email-daniel.vetter@ffwll.ch
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index e1fb52d..bff8922 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -590,6 +590,7 @@
spin_lock_init(&dev->buf_lock);
spin_lock_init(&dev->event_lock);
mutex_init(&dev->struct_mutex);
+ mutex_init(&dev->filelist_mutex);
mutex_init(&dev->ctxlist_mutex);
mutex_init(&dev->master_mutex);