>> + *
>> + * Return:
>> + * 0 on success, or an error on failing to expand the array.
>> + */
>> +int drm_sched_job_prealloc_dependency_slots(struct drm_sched_job
>> *job,
>> + unsigned int num_deps)
>> +{
>> + struct dma_fence *fence;
>> + u32 id = 0;
>> + int ret;
>> +
>> + while (num_deps--) {
>> + fence = dma_fence_get_stub();
>> + ret = xa_alloc(&job->dependencies, &id, fence,
>> xa_limit_32b,
>> + GFP_KERNEL);
> So this would fill the xarr with already signaled fences which then
> later will be replaced with unsignaled fences?
Yes, exactly that's the idea.
> Help me out here: would it also work to add NULL instead of that stub-
> fence?
Good question, idk. That's an implementation detail of the xarray.
Tvrtko also correctly pointed out that it is most likely a bad idea to use
dma_fence_is_signaled() in the critical code path.
I will try to dig through the xarray behavior up and update the patch if
possible.
Thanks,
Christian.
