diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-01-28 17:16:14 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2020-01-29 13:13:50 +0000 |
| commit | 8a5746982e0fdabae85990d90a9b80e107fcd450 (patch) | |
| tree | 47785698f67c2f75546d4f45c0b76094db6380e9 | |
| parent | ba12993c5228015c42dc46d634f5fa5717206c3b (diff) | |
drm/i915/execlist: Mark up racy read of execlists->pending[0]
We write to execlists->pending[0] in process_csb() to acknowledge the
completion of the ESLP update, outside of the main spinlock. When we
check the current status of the previous submission in
__execlists_submission_tasklet() we should therefore use READ_ONCE() to
reflect and document the unsynchronized read.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200128171614.3845825-1-chris@chris-wilson.co.uk
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_lrc.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c index f1ea2138cbba..677efdc7c301 100644 --- a/drivers/gpu/drm/i915/gt/intel_lrc.c +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c @@ -2347,7 +2347,7 @@ static void process_csb(struct intel_engine_cs *engine) static void __execlists_submission_tasklet(struct intel_engine_cs *const engine) { lockdep_assert_held(&engine->active.lock); - if (!engine->execlists.pending[0]) { + if (!READ_ONCE(engine->execlists.pending[0])) { rcu_read_lock(); /* protect peeking at execlists->active */ execlists_dequeue(engine); rcu_read_unlock(); |