[PATCH 5.10 40/57] bnxt_en: Fix mqprio and XDP ring checking logic

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Michael Chan <michael.chan@broadcom.com>

commit 2038cc592811209de20c4e094ca08bfb1e6fbc6c upstream.

In bnxt_reserve_rings(), there is logic to check that the number of TX
rings reserved is enough to cover all the mqprio TCs, but it fails to
account for the TX XDP rings.  So the check will always fail if there
are mqprio TCs and TX XDP rings.  As a result, the driver always fails
to initialize after the XDP program is attached and the device will be
brought down.  A subsequent ifconfig up will also fail because the
number of TX rings is set to an inconsistent number.  Fix the check to
properly account for TX XDP rings.  If the check fails, set the number
of TX rings back to a consistent number after calling netdev_reset_tc().

Fixes: 674f50a5b026 ("bnxt_en: Implement new method to reserve rings.")
Reviewed-by: Hongguang Gao <hongguang.gao@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -8761,10 +8761,14 @@ int bnxt_reserve_rings(struct bnxt *bp,
 		netdev_err(bp->dev, "ring reservation/IRQ init failure rc: %d\n", rc);
 		return rc;
 	}
-	if (tcs && (bp->tx_nr_rings_per_tc * tcs != bp->tx_nr_rings)) {
+	if (tcs && (bp->tx_nr_rings_per_tc * tcs !=
+		    bp->tx_nr_rings - bp->tx_nr_rings_xdp)) {
 		netdev_err(bp->dev, "tx ring reservation failure\n");
 		netdev_reset_tc(bp->dev);
-		bp->tx_nr_rings_per_tc = bp->tx_nr_rings;
+		if (bp->tx_nr_rings_xdp)
+			bp->tx_nr_rings_per_tc = bp->tx_nr_rings_xdp;
+		else
+			bp->tx_nr_rings_per_tc = bp->tx_nr_rings;
 		return -ENOMEM;
 	}
 	return 0;