Commit 290b5fe0 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Jakub Kicinski
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net: enetc: preserve TX ring priority across reconfiguration 



In the blamed commit, a rudimentary reallocation procedure for RX buffer
descriptors was implemented, for the situation when their format changes
between normal (no PTP) and extended (PTP).

enetc_hwtstamp_set() calls enetc_close() and enetc_open() in a sequence,
and this sequence loses information which was previously configured in
the TX BDR Mode Register, specifically via the enetc_set_bdr_prio() call.
The TX ring priority is configured by tc-mqprio and tc-taprio, and
affects important things for TSN such as the TX time of packets. The
issue manifests itself most visibly by the fact that isochron --txtime
reports premature packet transmissions when PTP is first enabled on an
enetc interface.

Save the TX ring priority in a new field in struct enetc_bdr (occupies a
2 byte hole on arm64) in order to make this survive a ring reconfiguration.

Fixes: 434cebab ("enetc: Add dynamic allocation of extended Rx BD rings")
Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarAlexander Lobakin <alexandr.lobakin@intel.com>
Link: https://lore.kernel.org/r/20221122130936.1704151-1-vladimir.oltean@nxp.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 9a234a2a

drivers/net/ethernet/freescale/enetc/enetc.c

+5 −3
Original line number Diff line number Diff line
@@ -2058,7 +2058,7 @@ static void enetc_setup_txbdr(struct enetc_hw *hw, struct enetc_bdr *tx_ring) 
	/* enable Tx ints by setting pkt thr to 1 */

	enetc_txbdr_wr(hw, idx, ENETC_TBICR0, ENETC_TBICR0_ICEN | 0x1);



	tbmr = ENETC_TBMR_EN;

	tbmr = ENETC_TBMR_EN | ENETC_TBMR_SET_PRIO(tx_ring->prio);

	if (tx_ring->ndev->features & NETIF_F_HW_VLAN_CTAG_TX)

		tbmr |= ENETC_TBMR_VIH;
@@ -2461,7 +2461,8 @@ int enetc_setup_tc_mqprio(struct net_device *ndev, void *type_data) 
		/* Reset all ring priorities to 0 */

		for (i = 0; i < priv->num_tx_rings; i++) {

			tx_ring = priv->tx_ring[i];

			enetc_set_bdr_prio(hw, tx_ring->index, 0);

			tx_ring->prio = 0;

			enetc_set_bdr_prio(hw, tx_ring->index, tx_ring->prio);

		}



		return 0;
@@ -2480,7 +2481,8 @@ int enetc_setup_tc_mqprio(struct net_device *ndev, void *type_data) 
	 */

	for (i = 0; i < num_tc; i++) {

		tx_ring = priv->tx_ring[i];

		enetc_set_bdr_prio(hw, tx_ring->index, i);

		tx_ring->prio = i;

		enetc_set_bdr_prio(hw, tx_ring->index, tx_ring->prio);

	}



	/* Reset the number of netdev queues based on the TC count */

drivers/net/ethernet/freescale/enetc/enetc.h

+1 −0
Original line number Diff line number Diff line
@@ -95,6 +95,7 @@ struct enetc_bdr { 
		void __iomem *rcir;

	};

	u16 index;

	u16 prio;

	int bd_count; /* # of BDs */

	int next_to_use;

	int next_to_clean;

drivers/net/ethernet/freescale/enetc/enetc_qos.c

+13 −8
Original line number Diff line number Diff line
@@ -137,6 +137,7 @@ int enetc_setup_tc_taprio(struct net_device *ndev, void *type_data) 
	struct tc_taprio_qopt_offload *taprio = type_data;

	struct enetc_ndev_priv *priv = netdev_priv(ndev);

	struct enetc_hw *hw = &priv->si->hw;

	struct enetc_bdr *tx_ring;

	int err;

	int i;
@@ -145,16 +146,20 @@ int enetc_setup_tc_taprio(struct net_device *ndev, void *type_data) 
		if (priv->tx_ring[i]->tsd_enable)

			return -EBUSY;



	for (i = 0; i < priv->num_tx_rings; i++)

		enetc_set_bdr_prio(hw, priv->tx_ring[i]->index,

				   taprio->enable ? i : 0);

	for (i = 0; i < priv->num_tx_rings; i++) {

		tx_ring = priv->tx_ring[i];

		tx_ring->prio = taprio->enable ? i : 0;

		enetc_set_bdr_prio(hw, tx_ring->index, tx_ring->prio);

	}



	err = enetc_setup_taprio(ndev, taprio);



	if (err)

		for (i = 0; i < priv->num_tx_rings; i++)

			enetc_set_bdr_prio(hw, priv->tx_ring[i]->index,

					   taprio->enable ? 0 : i);

	if (err) {

		for (i = 0; i < priv->num_tx_rings; i++) {

			tx_ring = priv->tx_ring[i];

			tx_ring->prio = taprio->enable ? 0 : i;

			enetc_set_bdr_prio(hw, tx_ring->index, tx_ring->prio);

		}

	}



	return err;

}