[PATCH 01/12] lpfc: Fix RQ buffer leakage when no IOCBs available

[James Smart <jsmart2021@gmail.com>]

The driver is occasionally see the following SLI Port error, requiring
reset and reinit:
 Port Status Event: ... error 1=0x52004a01, error 2=0x218

The failure means an RQ timeout. That is, the adapter had received
asynchronous receive frames, ran out of buffer slots to place the frames,
and the driver did not replenish the buffer slots before a timeout
occurred. The driver should not be so slow in replenishing buffers that
a timeout can occur.

When the driver received all the frames of a sequence, it allocates an IOCB
to put the frames in. In a situation where there was no IOCB available
for the frame of a sequence, the RQ buffer corresponding to the first frame
of the sequence was not returned to the FW. Eventually, with enough traffic
encountering the situation, the timeout occurred.

Fix by releasing the buffer back to firmware whenever there is no IOCB
for the first frame.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
---
 drivers/scsi/lpfc/lpfc_sli.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 64002b0cb02d..ab6f58bc80a4 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -17950,6 +17950,10 @@ lpfc_prep_seq(struct lpfc_vport *vport, struct hbq_dmabuf *seq_dmabuf)
 			list_add_tail(&iocbq->list, &first_iocbq->list);
 		}
 	}
+	/* Free the sequence's header buffer */
+	if (!first_iocbq)
+		lpfc_in_buf_free(vport->phba, &seq_dmabuf->dbuf);
+
 	return first_iocbq;
 }
 
-- 
2.13.7