[PATCH 18/20] scsi: ibmvfc: fix NVMe sub-queue registration failure disabling SCSI multiqueue

[Tyrel Datwyler <tyreld@linux.ibm.com>]

ibmvfc_reg_sub_crqs() clears vhost->do_enquiry unconditionally when any
channel registration fails.  The function is called for SCSI channels
first and then for NVMe channels (in ibmvfc_init_sub_crqs(),
ibmvfc_reset_crq(), and ibmvfc_reenable_crq_queue()).  If the NVMe
channel registration fails, do_enquiry is cleared even though SCSI
channels registered successfully, preventing the IBMVFC_CHANNEL_ENQUIRY
MAD from being sent and silently disabling multiqueue support for SCSI.

ibmvfc_init_sub_crqs() already handles NVMe *allocation* failure
correctly — it only clears nvme_enabled without touching do_enquiry.
The same logic needs to apply when NVMe *registration* fails.

Fix ibmvfc_reg_sub_crqs() to check channels->protocol in the failure
path: clear do_enquiry only for a SCSI channel failure (preserving
existing behaviour), and clear nvme_enabled instead for an NVMe channel
failure.  This covers all three call sites in one place.

Fixes: bf86ac3ca0d2 ("scsi: ibmvfc: alloc/dealloc sub-queues for nvme channels")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
---
 drivers/scsi/ibmvscsi/ibmvfc-core.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/ibmvscsi/ibmvfc-core.c b/drivers/scsi/ibmvscsi/ibmvfc-core.c
index 93189692191e..d79a6ae278a2 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc-core.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc-core.c
@@ -6527,7 +6527,10 @@ static void ibmvfc_reg_sub_crqs(struct ibmvfc_host *vhost,
 		if (ibmvfc_register_channel(vhost, channels, i)) {
 			for (j = i; j > 0; j--)
 				ibmvfc_deregister_channel(vhost, channels, j - 1);
-			vhost->do_enquiry = 0;
+			if (channels->protocol == IBMVFC_PROTO_SCSI)
+				vhost->do_enquiry = 0;
+			else
+				vhost->nvme_enabled = 0;
 			return;
 		}
 	}
-- 
2.55.0