On seqno rollover, we need to allocate ourselves a new cacheline. This might incur grabbing a new page and pinning it into the GGTT, with some rather unfortunate lockdep implications. To avoid a mutex, and more specifically pinning in the GGTT from inside the kernel context being used to flush the GGTT in emergencies, we will likely need to lift the next-cacheline allocation to a pre-reservation. Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> --- drivers/gpu/drm/i915/gt/intel_timeline.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c b/drivers/gpu/drm/i915/gt/intel_timeline.c index 465f87b65901..54e1e55f3c81 100644 --- a/drivers/gpu/drm/i915/gt/intel_timeline.c +++ b/drivers/gpu/drm/i915/gt/intel_timeline.c @@ -406,6 +406,8 @@ __intel_timeline_get_seqno(struct intel_timeline *tl, void *vaddr; int err; + might_lock(&tl->gt->ggtt->vm.mutex); + /* * If there is an outstanding GPU reference to this cacheline, * such as it being sampled by a HW semaphore on another timeline, -- 2.25.0 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
