During link bounce testing in a point-to-point topology, the
host may enter a soft lockup on the lpfc_worker thread:
    Call Trace:
     lpfc_work_done+0x1f3/0x1390 [lpfc]
     lpfc_do_work+0x16f/0x180 [lpfc]
     kthread+0xc7/0xe0
     ret_from_fork+0x3f/0x70

The driver was simultaneously setting a combination of flags
that caused lpfc_do_work()to effectively spin between slow path
work and new event data, causing the lockup.

Ensure in the typical wq completions, that new event data flags
are set if the slow path flag is running. The slow path will
eventually reschedule the wq handling.

Signed-off-by: Dick Kennedy <redacted>
Signed-off-by: James Smart <redacted>
---
 drivers/scsi/lpfc/lpfc_hbadisc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/lpfc/lpfc_hbadisc.c b/drivers/scsi/lpfc/lpfc_hbadisc.c
index b159a5c4e388..9265906d956e 100644
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c
+++ b/drivers/scsi/lpfc/lpfc_hbadisc.c

@@ -696,8 +696,9 @@ lpfc_work_done(struct lpfc_hba *phba)
 		      phba->hba_flag & HBA_SP_QUEUE_EVT)) {
 		if (pring->flag & LPFC_STOP_IOCB_EVENT) {
 			pring->flag |= LPFC_DEFERRED_RING_EVENT;
-			/* Set the lpfc data pending flag */
-			set_bit(LPFC_DATA_READY, &phba->data_flags);
+			/* Preserve legacy behavior. */
+			if (!(phba->hba_flag & HBA_SP_QUEUE_EVT))
+				set_bit(LPFC_DATA_READY, &phba->data_flags);
 		} else {
 			if (phba->link_state >= LPFC_LINK_UP ||
 			    phba->link_flag & LS_MDS_LOOPBACK) {

-- 
2.13.1