diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2020-12-17 09:15:24 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2020-12-17 19:56:17 +0000 |
| commit | e3ed90b8227eaf7d67ea0a2e81af9a09c71c8e8d (patch) | |
| tree | 7d8cebf69e0ad68a816a410e1a9ca786b2dc4f84 /drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | |
| parent | 460d02ba50763e73da033448d0d57f0aea23d039 (diff) | |
drm/i915/gt: Drain the breadcrumbs just once
Matthew Brost pointed out that the while-loop on a shared breadcrumb was
inherently fraught with danger as it competed with the other users of
the breadcrumbs. However, in order to completely drain the re-arming irq
worker, the while-loop is a necessity, despite my optimism that we could
force cancellation with a couple of irq_work invocations.
Given that we can't merely drop the while-loop, use an activity counter on
the breadcrumbs to detect when we are parking the breadcrumbs for the
last time.
Based on a patch by Matthew Brost.
Reported-by: Matthew Brost <matthew.brost@intel.com>
Suggested-by: Matthew Brost <matthew.brost@intel.com>
Fixes: 9d5612ca165a ("drm/i915/gt: Defer enabling the breadcrumb interrupt to after submission")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201217091524.10258-1-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_breadcrumbs.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c index 00918300f53f..3c62fd6daa76 100644 --- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c +++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c @@ -332,17 +332,19 @@ void intel_breadcrumbs_reset(struct intel_breadcrumbs *b) spin_unlock_irqrestore(&b->irq_lock, flags); } -void intel_breadcrumbs_park(struct intel_breadcrumbs *b) +void __intel_breadcrumbs_park(struct intel_breadcrumbs *b) { - /* Kick the work once more to drain the signalers */ + if (!READ_ONCE(b->irq_armed)) + return; + + /* Kick the work once more to drain the signalers, and disarm the irq */ irq_work_sync(&b->irq_work); - while (unlikely(READ_ONCE(b->irq_armed))) { + while (READ_ONCE(b->irq_armed) && !atomic_read(&b->active)) { local_irq_disable(); signal_irq_work(&b->irq_work); local_irq_enable(); cond_resched(); } - GEM_BUG_ON(!list_empty(&b->signalers)); } void intel_breadcrumbs_free(struct intel_breadcrumbs *b) |