[PATCH net-next 06/14] bnxt_en: Set initial default RX and TX ring numbers the same in combined mode.

[Michael Chan <michael.chan@broadcom.com>]

In combined mode, the driver is currently not setting RX and TX ring
numbers the same when firmware can allocate more RX than TX or vice versa.
This will confuse the user as the ethtool convention assumes they are the
same in combined mode.  Fix it by adding bnxt_trim_dflt_sh_rings() to trim
RX and TX ring numbers to be the same as the completion ring number in
combined mode.

Note that if TCs are enabled and/or XDP is enabled, the number of TX rings
will not be the same as RX rings in combined mode.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index f87e0bd..177c8f5 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -8030,6 +8030,17 @@ static int bnxt_get_dflt_rings(struct bnxt *bp, int *max_rx, int *max_tx,
 	return rc;
 }
 
+/* In initial default shared ring setting, each shared ring must have a
+ * RX/TX ring pair.
+ */
+static void bnxt_trim_dflt_sh_rings(struct bnxt *bp)
+{
+	bp->cp_nr_rings = min_t(int, bp->tx_nr_rings_per_tc, bp->rx_nr_rings);
+	bp->rx_nr_rings = bp->cp_nr_rings;
+	bp->tx_nr_rings_per_tc = bp->cp_nr_rings;
+	bp->tx_nr_rings = bp->tx_nr_rings_per_tc;
+}
+
 static int bnxt_set_dflt_rings(struct bnxt *bp, bool sh)
 {
 	int dflt_rings, max_rx_rings, max_tx_rings, rc;
@@ -8045,10 +8056,18 @@ static int bnxt_set_dflt_rings(struct bnxt *bp, bool sh)
 		return rc;
 	bp->rx_nr_rings = min_t(int, dflt_rings, max_rx_rings);
 	bp->tx_nr_rings_per_tc = min_t(int, dflt_rings, max_tx_rings);
+	if (sh)
+		bnxt_trim_dflt_sh_rings(bp);
+	else
+		bp->cp_nr_rings = bp->tx_nr_rings_per_tc + bp->rx_nr_rings;
+	bp->tx_nr_rings = bp->tx_nr_rings_per_tc;
 
 	rc = bnxt_hwrm_reserve_tx_rings(bp, &bp->tx_nr_rings_per_tc);
 	if (rc)
 		netdev_warn(bp->dev, "Unable to reserve tx rings\n");
+	bp->tx_nr_rings_per_tc = bp->tx_nr_rings;
+	if (sh)
+		bnxt_trim_dflt_sh_rings(bp);
 
 	bp->tx_nr_rings = bp->tx_nr_rings_per_tc;
 	bp->cp_nr_rings = sh ? max_t(int, bp->tx_nr_rings, bp->rx_nr_rings) :
-- 
1.8.3.1