Messages in this thread | | | From | Alexander Lobakin <> | Subject | Re: [PATCH net] net: enetc: preserve TX ring priority across reconfiguration | Date | Wed, 23 Nov 2022 16:51:16 +0100 |
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From: Vladimir Oltean <vladimir.oltean@nxp.com> Date: Tue, 22 Nov 2022 15:09:36 +0200
> 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: 434cebabd3a2 ("enetc: Add dynamic allocation of extended Rx BD rings") > Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> > --- > drivers/net/ethernet/freescale/enetc/enetc.c | 8 ++++--- > drivers/net/ethernet/freescale/enetc/enetc.h | 1 + > .../net/ethernet/freescale/enetc/enetc_qos.c | 21 ++++++++++++------- > 3 files changed, 19 insertions(+), 11 deletions(-)
[...]
> 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;
Side note: is that `taprio ? 0 : i` correct? It's an error path IIUC, why not just unconditional 0? I guess it is, so
Reviewed-by: Alexander Lobakin <alexandr.lobakin@intel.com>
> + enetc_set_bdr_prio(hw, tx_ring->index, tx_ring->prio); > + } > + } > > return err; > } > -- > 2.34.1
Thanks, Olek
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