From: Suganath Prabu S suganath-prabu.subramani@broadcom.com
[ Upstream commit e2fac6c44ae06e58ac02181b048af31195883c31 ]
Do not cancel current running firmware event work if the event type is different from MPT3SAS_REMOVE_UNRESPONDING_DEVICES. Otherwise a deadlock can be observed while cancelling the current firmware event work if a hard reset operation is called as part of processing the current event.
Link: https://lore.kernel.org/r/20210518051625.1596742-2-suganath-prabu.subramani@... Signed-off-by: Suganath Prabu S suganath-prabu.subramani@broadcom.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/mpt3sas/mpt3sas_scsih.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c index 008f734698f7..31c384108bc9 100644 --- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c +++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c @@ -3526,6 +3526,28 @@ _scsih_fw_event_cleanup_queue(struct MPT3SAS_ADAPTER *ioc) ioc->fw_events_cleanup = 1; while ((fw_event = dequeue_next_fw_event(ioc)) || (fw_event = ioc->current_event)) { + + /* + * Don't call cancel_work_sync() for current_event + * other than MPT3SAS_REMOVE_UNRESPONDING_DEVICES; + * otherwise we may observe deadlock if current + * hard reset issued as part of processing the current_event. + * + * Orginal logic of cleaning the current_event is added + * for handling the back to back host reset issued by the user. + * i.e. during back to back host reset, driver use to process + * the two instances of MPT3SAS_REMOVE_UNRESPONDING_DEVICES + * event back to back and this made the drives to unregister + * the devices from SML. + */ + + if (fw_event == ioc->current_event && + ioc->current_event->event != + MPT3SAS_REMOVE_UNRESPONDING_DEVICES) { + ioc->current_event = NULL; + continue; + } + /* * Wait on the fw_event to complete. If this returns 1, then * the event was never executed, and we need a put for the