From 2e482655019ab6fcfe8865b62432c6d03f0b5f80 Mon Sep 17 00:00:00 2001 From: Alistair Francis Date: Tue, 2 Sep 2025 13:52:11 +1000 Subject: [PATCH] nvme: Use non zero KATO for persistent discovery connections The NVMe Base Specification 2.1 states that: """ A host requests an explicit persistent connection ... by specifying a non-zero Keep Alive Timer value in the Connect command. """ As such if we are starting a persistent connection to a discovery controller and the KATO is currently 0 we need to update KATO to a non zero value to avoid continuous timeouts on the target. Signed-off-by: Alistair Francis Reviewed-by: Hannes Reinecke Reviewed-by: Christoph Hellwig Signed-off-by: Keith Busch --- drivers/nvme/host/core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index a46f0f2d1c37..42c5f05680f1 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -4991,8 +4991,14 @@ void nvme_start_ctrl(struct nvme_ctrl *ctrl) * checking that they started once before, hence are reconnecting back. */ if (test_bit(NVME_CTRL_STARTED_ONCE, &ctrl->flags) && - nvme_discovery_ctrl(ctrl)) + nvme_discovery_ctrl(ctrl)) { + if (!ctrl->kato) { + nvme_stop_keep_alive(ctrl); + ctrl->kato = NVME_DEFAULT_KATO; + nvme_start_keep_alive(ctrl); + } nvme_change_uevent(ctrl, "NVME_EVENT=rediscover"); + } if (ctrl->queue_count > 1) { nvme_queue_scan(ctrl); -- 2.51.0