[PATCH 4.7 059/184] IB/hfi1: Reset QSFP on every run through channel tuning

[Greg Kroah-Hartman]

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

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

From: Easwar Hariharan <easwar.hariharan@xxxxxxxxx>

commit b5e710195492f682d93097cddac13e594d39a946 upstream.

Active QSFP cables were reset only every alternate iteration of the
channel tuning algorithm instead of every iteration due to incorrect
reset of the flag that controlled QSFP reset, resulting in using stale
QSFP status in the channel tuning algorithm.

Fixes: 8ebd4cf1852a ("Add active and optical cable support")
Reviewed-by: Dean Luick <dean.luick@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: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/infiniband/hw/hfi1/platform.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/infiniband/hw/hfi1/platform.c
+++ b/drivers/infiniband/hw/hfi1/platform.c
@@ -638,9 +638,13 @@ static int tune_active_qsfp(struct hfi1_
 	if (ret)
 		return ret;
 
+	/*
+	 * We'll change the QSFP memory contents from here on out, thus we set a
+	 * flag here to remind ourselves to reset the QSFP module. This prevents
+	 * reuse of stale settings established in our previous pass through.
+	 */
 	if (ppd->qsfp_info.reset_needed) {
 		reset_qsfp(ppd);
-		ppd->qsfp_info.reset_needed = 0;
 		refresh_qsfp_cache(ppd, &ppd->qsfp_info);
 	} else {
 		ppd->qsfp_info.reset_needed = 1;