diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_request.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 784c05ac5cca..973eceabbcca 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -969,9 +969,16 @@ i915_request_await_start(struct i915_request *rq, struct i915_request *signal) if (i915_request_started(signal)) return 0; + /* + * The caller holds a reference on @signal, but we do not serialise + * against it being retired and removed from the lists. + * + * We do not hold a reference to the request before @signal, and + * so must be very careful to ensure that it is not _recycled_ as + * we follow the link backwards. + */ fence = NULL; rcu_read_lock(); - spin_lock_irq(&signal->lock); do { struct list_head *pos = READ_ONCE(signal->link.prev); struct i915_request *prev; @@ -1002,7 +1009,6 @@ i915_request_await_start(struct i915_request *rq, struct i915_request *signal) fence = &prev->fence; } while (0); - spin_unlock_irq(&signal->lock); rcu_read_unlock(); if (!fence) return 0; |