diff options
author | Johannes Berg <[email protected]> | 2016-08-11 11:50:21 +0200 |
---|---|---|
committer | Ingo Molnar <[email protected]> | 2016-08-18 15:36:13 +0200 |
commit | f17b3ea3d2df7c9bf3ce1dbd65b5fd7061f8e787 (patch) | |
tree | 5d09e44a82d1aac1bb0658aefbba3bfee90e561c | |
parent | 3684b03d8e9a889eda94ee74421959a9d55e5e19 (diff) |
Revert "drm/fb-helper: Reduce READ_ONCE(master) to lockless_dereference"
This reverts commit:
fa7d81bb3c269 ("drm/fb-helper: Reduce READ_ONCE(master) to lockless_dereference")
As Peter explained:
[...] lockless_dereference() is _stronger_ than READ_ONCE(), not weaker.
[...]
Also, clue is in the name: 'dereference', you don't actually dereference
the pointer here, only load it.
My next patch breaks the compile without this revert, because it assumes
you want to deference and thus also need the struct type visible (which
it isn't here), so revert it.
Tested-by: Paul E. McKenney <[email protected]>
Signed-off-by: Johannes Berg <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Daniel Vetter <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
-rw-r--r-- | drivers/gpu/drm/drm_fb_helper.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c index ce54e985d91b..0a06f9120b5a 100644 --- a/drivers/gpu/drm/drm_fb_helper.c +++ b/drivers/gpu/drm/drm_fb_helper.c @@ -464,7 +464,7 @@ static bool drm_fb_helper_is_bound(struct drm_fb_helper *fb_helper) /* Sometimes user space wants everything disabled, so don't steal the * display if there's a master. */ - if (lockless_dereference(dev->master)) + if (READ_ONCE(dev->master)) return false; drm_for_each_crtc(crtc, dev) { |