3.18-stable review patch. If anyone has any objections, please let me know.
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From: James Smart jsmart2021@gmail.com
[ Upstream commit 161df4f09987ae2e9f0f97f0b38eee298b4a39ff ]
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 dick.kennedy@broadcom.com Signed-off-by: James Smart james.smart@broadcom.com Reviewed-by: Hannes Reinecke hare@suse.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/scsi/lpfc/lpfc_hbadisc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
--- a/drivers/scsi/lpfc/lpfc_hbadisc.c +++ b/drivers/scsi/lpfc/lpfc_hbadisc.c @@ -716,8 +716,9 @@ 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) { pring->flag &= ~LPFC_DEFERRED_RING_EVENT;