* retired, so if the fence is not found it means there is nothing
         * to wait for
         */
-       ret = mutex_lock_interruptible(&queue->idr_lock);
-       if (ret)
-               return ret;
+       spin_lock(&queue->idr_lock);
        fence = idr_find(&queue->fence_idr, fence_id);
        if (fence)
                fence = dma_fence_get_rcu(fence);
-       mutex_unlock(&queue->idr_lock);
+       spin_unlock(&queue->idr_lock);
 
        if (!fence)
                return 0;
 
        unsigned i;
 
        if (submit->fence_id) {
-               mutex_lock(&submit->queue->idr_lock);
+               spin_lock(&submit->queue->idr_lock);
                idr_remove(&submit->queue->fence_idr, submit->fence_id);
-               mutex_unlock(&submit->queue->idr_lock);
+               spin_unlock(&submit->queue->idr_lock);
        }
 
        dma_fence_put(submit->user_fence);
 
        submit->nr_cmds = i;
 
-       mutex_lock(&queue->idr_lock);
+       spin_lock(&queue->idr_lock);
 
        /*
         * If using userspace provided seqno fence, validate that the id
         */
        if ((args->flags & MSM_SUBMIT_FENCE_SN_IN) &&
                        idr_find(&queue->fence_idr, args->fence)) {
-               mutex_unlock(&queue->idr_lock);
+               spin_unlock(&queue->idr_lock);
                ret = -EINVAL;
                goto out;
        }
                                                    INT_MAX, GFP_KERNEL);
        }
 
-       mutex_unlock(&queue->idr_lock);
+       spin_unlock(&queue->idr_lock);
 
        if (submit->fence_id < 0) {
                ret = submit->fence_id;
 
                *id = queue->id;
 
        idr_init(&queue->fence_idr);
-       mutex_init(&queue->idr_lock);
+       spin_lock_init(&queue->idr_lock);
        mutex_init(&queue->lock);
 
        list_add_tail(&queue->node, &ctx->submitqueues);