From: James Smart jsmart2021@gmail.com
[ Upstream commit 07b8582430370097238b589f4e24da7613ca6dd3 ]
Symptoms were seen of the driver not having valid data for mailbox commands. After debugging, the following sequence was found:
The driver maintains a port-wide pointer of the mailbox command that is currently in execution. Once finished, the port-wide pointer is cleared (done in lpfc_sli4_mq_release()). The next mailbox command issued will set the next pointer and so on.
The mailbox response data is only copied if there is a valid port-wide pointer.
In the failing case, it was seen that a new mailbox command was being attempted in parallel with the completion. The parallel path was seeing the mailbox no long in use (flag check under lock) and thus set the port pointer. The completion path had cleared the active flag under lock, but had not touched the port pointer. The port pointer is cleared after the lock is released. In this case, the completion path cleared the just-set value by the parallel path.
Fix by making the calls that clear mbox state/port pointer while under lock. Also slightly cleaned up the error path.
Link: https://lore.kernel.org/r/20190922035906.10977-8-jsmart2021@gmail.com Signed-off-by: Dick Kennedy dick.kennedy@broadcom.com Signed-off-by: James Smart jsmart2021@gmail.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/scsi/lpfc/lpfc_sli.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index 755803ff6cfef..51b06b8a1dc72 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -12936,13 +12936,19 @@ send_current_mbox: phba->sli.sli_flag &= ~LPFC_SLI_MBOX_ACTIVE; /* Setting active mailbox pointer need to be in sync to flag clear */ phba->sli.mbox_active = NULL; + if (bf_get(lpfc_trailer_consumed, mcqe)) + lpfc_sli4_mq_release(phba->sli4_hba.mbx_wq); spin_unlock_irqrestore(&phba->hbalock, iflags); /* Wake up worker thread to post the next pending mailbox command */ lpfc_worker_wake_up(phba); + return workposted; + out_no_mqe_complete: + spin_lock_irqsave(&phba->hbalock, iflags); if (bf_get(lpfc_trailer_consumed, mcqe)) lpfc_sli4_mq_release(phba->sli4_hba.mbx_wq); - return workposted; + spin_unlock_irqrestore(&phba->hbalock, iflags); + return false; }
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