Subject: RE: [PATCH net-next v25 08/13] rtase: Implement net_device_ops

From: Justin Lai <[email-masked]>
Date: Mon, 29 Jul 2024 11:39:03 +0000

> On Mon, Jul 29, 2024 at 02:21:16PM +0800, Justin Lai wrote:
> > 1. Implement .ndo_set_rx_mode so that the device can change address
> > list filtering.
> > 2. Implement .ndo_set_mac_address so that mac address can be changed.
> > 3. Implement .ndo_change_mtu so that mtu can be changed.
> > 4. Implement .ndo_tx_timeout to perform related processing when the
> > transmitter does not make any progress.
> > 5. Implement .ndo_get_stats64 to provide statistics that are called
> > when the user wants to get network device usage.
> > 6. Implement .ndo_vlan_rx_add_vid to register VLAN ID when the device
> > supports VLAN filtering.
> > 7. Implement .ndo_vlan_rx_kill_vid to unregister VLAN ID when the
> > device supports VLAN filtering.
> > 8. Implement the .ndo_setup_tc to enable setting any "tc" scheduler,
> > classifier or action on dev.
> > 9. Implement .ndo_fix_features enables adjusting requested feature
> > flags based on device-specific constraints.
> > 10. Implement .ndo_set_features enables updating device configuration
> > to new features.
> >
> > Signed-off-by: Justin Lai <[email-masked]>
> > ---
> >  .../net/ethernet/realtek/rtase/rtase_main.c   | 235 ++++++++++++++++++
> >  1 file changed, 235 insertions(+)
> >
> > diff --git a/drivers/net/ethernet/realtek/rtase/rtase_main.c
> > b/drivers/net/ethernet/realtek/rtase/rtase_main.c
> > index 8fd69d96219f..80673fa1e9a3 100644
> 
> [...]
> 
> > +static void rtase_dump_state(const struct net_device *dev) {
> 
> [...]
> 
> > +
> > +     netdev_err(dev, "tx_packets %lld\n",
> > +                le64_to_cpu(counters->tx_packets));
> > +     netdev_err(dev, "rx_packets %lld\n",
> > +                le64_to_cpu(counters->rx_packets));
> > +     netdev_err(dev, "tx_errors %lld\n",
> > +                le64_to_cpu(counters->tx_errors));
> > +     netdev_err(dev, "rx_errors %d\n",
> > +                le32_to_cpu(counters->rx_errors));
> > +     netdev_err(dev, "rx_missed %d\n",
> > +                le16_to_cpu(counters->rx_missed));
> > +     netdev_err(dev, "align_errors %d\n",
> > +                le16_to_cpu(counters->align_errors));
> > +     netdev_err(dev, "tx_one_collision %d\n",
> > +                le32_to_cpu(counters->tx_one_collision));
> > +     netdev_err(dev, "tx_multi_collision %d\n",
> > +                le32_to_cpu(counters->tx_multi_collision));
> > +     netdev_err(dev, "rx_unicast %lld\n",
> > +                le64_to_cpu(counters->rx_unicast));
> > +     netdev_err(dev, "rx_broadcast %lld\n",
> > +                le64_to_cpu(counters->rx_broadcast));
> > +     netdev_err(dev, "rx_multicast %d\n",
> > +                le32_to_cpu(counters->rx_multicast));
> > +     netdev_err(dev, "tx_aborted %d\n",
> > +                le16_to_cpu(counters->tx_aborted));
> > +     netdev_err(dev, "tx_underun %d\n",
> > +                le16_to_cpu(counters->tx_underun));
> 
> You use le64/32/16_to_cpu here for all stats, but below in rtase_get_stats64, it
> is only used for tx_errors.
> 
> The code should probably be consistent? Either you do or don't need to use
> them?
> 
> > +}
> > +
> [...]
> > +
> > +static void rtase_get_stats64(struct net_device *dev,
> > +                           struct rtnl_link_stats64 *stats) {
> > +     const struct rtase_private *tp = netdev_priv(dev);
> > +     const struct rtase_counters *counters;
> > +
> > +     counters = tp->tally_vaddr;
> > +
> > +     dev_fetch_sw_netstats(stats, dev->tstats);
> > +
> > +     /* fetch additional counter values missing in stats collected by driver
> > +      * from tally counter
> > +      */
> > +     rtase_dump_tally_counter(tp);
> > +     stats->rx_errors = tp->stats.rx_errors;
> > +     stats->tx_errors = le64_to_cpu(counters->tx_errors);
> > +     stats->rx_dropped = tp->stats.rx_dropped;
> > +     stats->tx_dropped = tp->stats.tx_dropped;
> > +     stats->multicast = tp->stats.multicast;
> > +     stats->rx_length_errors = tp->stats.rx_length_errors;
> 
> See above; le64_to_cpu for tx_errors, but not the rest of the stats. Why?

The rtase_dump_state() function is primarily used to dump certain hardware
information. Following discussions with Jakub, it was suggested that we
should design functions to accumulate the 16-bit and 32-bit counter values
to prevent potential overflow issues due to the limited size of the
counters. However, the final decision was to temporarily refrain from
reporting 16-bit and 32-bit counter information. Additionally, since
tx_packet and rx_packet data are already provided through tstat, we
ultimately opted to modify it to the current rtase_get_stats64() function.

Thanks
Justin