[PATCH 4.9 109/241] IB/hfi1: Check for QSFP presence before attempting reads

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Easwar Hariharan <easwar.hariharan@xxxxxxxxx>


[ Upstream commit fb897ad315643e5dc1092a115b3cec914b66df9d ]

Attempting to read the status of a QSFP cable creates noise in the logs
and misses out on setting an appropriate Offline/Disabled Reason if the
cable is not plugged in. Check for this prior to attempting the read and
attendant retries.

Fixes: 673b975f1fba ("IB/hfi1: Add QSFP sanity pre-check")
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Easwar Hariharan <easwar.hariharan@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/infiniband/hw/hfi1/chip.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -9489,8 +9489,11 @@ static int test_qsfp_read(struct hfi1_pp
 	int ret;
 	u8 status;
 
-	/* report success if not a QSFP */
-	if (ppd->port_type != PORT_TYPE_QSFP)
+	/*
+	 * Report success if not a QSFP or, if it is a QSFP, but the cable is
+	 * not present
+	 */
+	if (ppd->port_type != PORT_TYPE_QSFP || !qsfp_mod_present(ppd))
 		return 0;
 
 	/* read byte 2, the status byte */