[PATCH] nvme: Inform controller of doorbell config before unquiescing IO queues

From: William Butler
Date: Wed Jan 10 2024 - 13:29:08 EST


During resets, if queues are unquiesced first, then the host can submit
IOs to the controller using shadow doorbell logic but the controller
won't be aware. This can lead to necessary MMIO doorbells from being
not issued, causing requests to be delayed and timed-out.

Signed-off-by: William Butler <wab@xxxxxxxxxx>
---
drivers/nvme/host/pci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 61af7ff1a9d6..f87c51a946b3 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2743,10 +2743,10 @@ static void nvme_reset_work(struct work_struct *work)
* controller around but remove all namespaces.
*/
if (dev->online_queues > 1) {
+ nvme_dbbuf_set(dev);
nvme_unquiesce_io_queues(&dev->ctrl);
nvme_wait_freeze(&dev->ctrl);
nvme_pci_update_nr_queues(dev);
- nvme_dbbuf_set(dev);
nvme_unfreeze(&dev->ctrl);
} else {
dev_warn(dev->ctrl.device, "IO queues lost\n");
--
2.43.0.275.g3460e3d667-goog