[PATCH net] bnxt_en: Fix ethtool self-test loopback.

The current code has 2 problems.  It assumes that the RX ring for
the loopback packet is combined with the TX ring.  This is not
true if the ethtool channels are set to non-combined mode.  The
second problem is that it won't work on 57500 chips without
adjusting the logic to get the proper completion ring (cpr) pointer.
Fix both issues by locating the proper cpr pointer through the RX
ring.

Fixes: e44758b78ae8 ("bnxt_en: Use bnxt_cp_ring_info struct pointer as parameter for RX path.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
index 6cc69a5..6b51f4d 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c

@@ -2572,6 +2572,7 @@ static int bnxt_poll_loopback(struct bnxt *bp, struct bnxt_cp_ring_info *cpr,
 static int bnxt_run_loopback(struct bnxt *bp)
 {
 	struct bnxt_tx_ring_info *txr = &bp->tx_ring[0];
+	struct bnxt_rx_ring_info *rxr = &bp->rx_ring[0];
 	struct bnxt_cp_ring_info *cpr;
 	int pkt_size, i = 0;
 	struct sk_buff *skb;

@@ -2579,7 +2580,9 @@ static int bnxt_run_loopback(struct bnxt *bp)
 	u8 *data;
 	int rc;
 
-	cpr = &txr->bnapi->cp_ring;
+	cpr = &rxr->bnapi->cp_ring;
+	if (bp->flags & BNXT_FLAG_CHIP_P5)
+		cpr = cpr->cp_ring_arr[BNXT_RX_HDL];
 	pkt_size = min(bp->dev->mtu + ETH_HLEN, bp->rx_copy_thresh);
 	skb = netdev_alloc_skb(bp->dev, pkt_size);
 	if (!skb)

-- 
2.5.1

From: Michael Chan <michael.chan@broadcom.com>
Date: Wed, 19 Dec 2018 13:46:50 -0500

The current code has 2 problems.  It assumes that the RX ring for
the loopback packet is combined with the TX ring.  This is not
true if the ethtool channels are set to non-combined mode.  The
second problem is that it won't work on 57500 chips without
adjusting the logic to get the proper completion ring (cpr) pointer.
Fix both issues by locating the proper cpr pointer through the RX
ring.

Fixes: e44758b78ae8 ("bnxt_en: Use bnxt_cp_ring_info struct pointer as parameter for RX path.")
Signed-off-by: Michael Chan <michael.chan@broadcom.com>

Applied, thanks Michael.