diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2016-08-09 17:47:52 +0100 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2016-08-10 10:37:49 +0100 |
| commit | dbd6ef29a74e6db22e037fc3d481c1dbca596f80 (patch) | |
| tree | 9d7d010c8c9520eca1e03d26f78978d06685c9ec /drivers/gpu/drm/i915/intel_ringbuffer.c | |
| parent | 83348ba84ee0d5d4d982e5382bfbc8b2a2d05e75 (diff) | |
drm/i915: Use RCU to annotate and enforce protection for breadcrumb's bh
The bottom-half we use for processing the breadcrumb interrupt is a
task, which is an RCU protected struct. When accessing this struct, we
need to be holding the RCU read lock to prevent it disappearing beneath
us. We can use the RCU annotation to mark our irq_seqno_bh pointer as
being under RCU guard and then use the RCU accessors to both provide
correct ordering of access through the pointer.
Most notably, this fixes the access from hard irq context to use the RCU
read lock, which both Daniel and Tvrtko complained about.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1470761272-1245-3-git-send-email-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/intel_ringbuffer.c')
| -rw-r--r-- | drivers/gpu/drm/i915/intel_ringbuffer.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index e08a1e1b04e4..16b726fe33eb 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -2410,9 +2410,7 @@ void intel_engine_init_seqno(struct intel_engine_cs *engine, u32 seqno) /* After manually advancing the seqno, fake the interrupt in case * there are any waiters for that seqno. */ - rcu_read_lock(); intel_engine_wakeup(engine); - rcu_read_unlock(); } static void gen6_bsd_submit_request(struct drm_i915_gem_request *request) |