nvme/pci: Suspend queues after deleting them

The driver had been abusing the cq_vector state to know if new submissions were safe, but that was before we could quiesce blk-mq. If the controller happens to get an interrupt through while we're suspending those queues, 'no irq handler' warnings may occur.

This patch will disable the interrupts only after the queues are deleted.

Reported-by Jianchao Wang <jianchao.w.wang at oracle.com>

Signed-off-by Keith Busch <keith.busch at intel.com>

---
v1 -> v2:

Forgot to subtract 1 from the online queues. It happened to pass the test, but still not correct.

 drivers/nvme/host/pci.c | 27 ++++++++-------------------
 1 file changed, 8 insertions(+), 19 deletions(-)

drivers/nvme/host/pci.c +8 -19

index c46c239cc1ff..e2342d365d3c 100644
@@ -1324,9 +1324,6 @@ static void nvme_disable_admin_queue(struct nvme_dev *dev, bool shutdown)
 {
 	struct nvme_queue *nvmeq = &dev->queues[0];
 
-	if (nvme_suspend_queue(nvmeq))
-		return;
-
 	if (shutdown)
 		nvme_shutdown_ctrl(&dev->ctrl);
 	else

@@ -2011,9 +2008,9 @@ static int nvme_delete_queue(struct nvme_queue *nvmeq, u8 opcode)
 	return 0;
 }
 
-static void nvme_disable_io_queues(struct nvme_dev *dev, int queues)
+static void nvme_disable_io_queues(struct nvme_dev *dev)
 {
-	int pass;
+	int pass, queues = dev->online_queues - 1;
 	unsigned long timeout;
 	u8 opcode = nvme_admin_delete_sq;
 

@@ -2164,7 +2161,7 @@ static void nvme_pci_disable(struct nvme_dev *dev)
 
 static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 {
-	int i, queues;
+	int i;
 	bool dead = true;
 	struct pci_dev *pdev = to_pci_dev(dev->dev);
 

@@ -2199,21 +2196,13 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 	}
 	nvme_stop_queues(&dev->ctrl);
 
-	queues = dev->online_queues - 1;
-	for (i = dev->ctrl.queue_count - 1; i > 0; i--)
-		nvme_suspend_queue(&dev->queues[i]);
-
-	if (dead) {
-		/* A device might become IO incapable very soon during
-		 * probe, before the admin queue is configured. Thus,
-		 * queue_count can be 0 here.
-		 */
-		if (dev->ctrl.queue_count)
-			nvme_suspend_queue(&dev->queues[0]);
-	} else {
-		nvme_disable_io_queues(dev, queues);
+	if (!dead) {
+		nvme_disable_io_queues(dev);
 		nvme_disable_admin_queue(dev, shutdown);
 	}
+	for (i = dev->ctrl.queue_count - 1; i >= 0; i--)
+		nvme_suspend_queue(&dev->queues[i]);
+
 	nvme_pci_disable(dev);
 
 	blk_mq_tagset_busy_iter(&dev->tagset, nvme_cancel_request, &dev->ctrl);