NVMe: Fix admin queue ring wrap

The tag set queue depth needs to be one less than the h/w queue depth
so we don't wrap the circular buffer. This conforms to the specification
defined "Full Queue" condition.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Keith Busch 2016-01-04 09:10:55 -07:00 committed by Jens Axboe
parent 4490733250
commit e3e9d50cd6
1 changed files with 6 additions and 1 deletions

View File

@ -1271,7 +1271,12 @@ static int nvme_alloc_admin_tags(struct nvme_dev *dev)
if (!dev->ctrl.admin_q) {
dev->admin_tagset.ops = &nvme_mq_admin_ops;
dev->admin_tagset.nr_hw_queues = 1;
dev->admin_tagset.queue_depth = NVME_AQ_BLKMQ_DEPTH;
/*
* Subtract one to leave an empty queue entry for 'Full Queue'
* condition. See NVM-Express 1.2 specification, section 4.1.2.
*/
dev->admin_tagset.queue_depth = NVME_AQ_BLKMQ_DEPTH - 1;
dev->admin_tagset.timeout = ADMIN_TIMEOUT;
dev->admin_tagset.numa_node = dev_to_node(dev->dev);
dev->admin_tagset.cmd_size = nvme_cmd_size(dev);