Re: [PATCH v2 net-next] ionic: add support for ethtool extended stat link_down_count

[Larysa Zaremba <larysa.zaremba@intel.com>]

On Fri, Jun 09, 2023 at 10:54:47AM -0700, Shannon Nelson wrote:
> On 6/9/23 7:45 AM, Larysa Zaremba wrote:
> > 
> > On Thu, Jun 08, 2023 at 10:50:16PM -0700, Shannon Nelson wrote:
> > > From: Nitya Sunkad <nitya.sunkad@amd.com>
> > > 
> > > Following the example of 'commit 9a0f830f8026 ("ethtool: linkstate:
> > > add a statistic for PHY down events")', added support for link down
> > > events.
> > > 
> > > Added callback ionic_get_link_ext_stats to ionic_ethtool.c to support
> > > link_down_count, a property of netdev that gets reported exclusively
> > > on physical link down events.
> > 
> > Commit message hasn't changed since v1, despite the comment about usage of
> > "added" vs "add".
> 
> Sorry, missed that.  Not sure this is worth another spin by itself.
> 
> > 
> > > 
> > > Run ethtool -I <devname> to display the device link down count.
> > > 
> > > Signed-off-by: Nitya Sunkad <nitya.sunkad@amd.com>
> > > Signed-off-by: Shannon Nelson <shannon.nelson@amd.com>
> > > ---
> > > v2: Report link_down_count only on PF, not on VF
> > > 
> > >   drivers/net/ethernet/pensando/ionic/ionic_ethtool.c | 10 ++++++++++
> > >   drivers/net/ethernet/pensando/ionic/ionic_lif.c     |  1 +
> > >   drivers/net/ethernet/pensando/ionic/ionic_lif.h     |  1 +
> > >   3 files changed, 12 insertions(+)
> > > 
> > > diff --git a/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c b/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
> > > index 9b2b96fa36af..3a6b0a9bc241 100644
> > > --- a/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
> > > +++ b/drivers/net/ethernet/pensando/ionic/ionic_ethtool.c
> > > @@ -104,6 +104,15 @@ static void ionic_get_regs(struct net_device *netdev, struct ethtool_regs *regs,
> > >        memcpy_fromio(p + offset, lif->ionic->idev.dev_cmd_regs->words, size);
> > >   }
> > > 
> > > +static void ionic_get_link_ext_stats(struct net_device *netdev,
> > > +                                  struct ethtool_link_ext_stats *stats)
> > > +{
> > > +     struct ionic_lif *lif = netdev_priv(netdev);
> > > +
> > > +     if (lif->ionic->pdev->is_physfn)
> > 
> > Maybe
> > 
> > ionic->pdev->device == PCI_DEVICE_ID_PENSANDO_IONIC_ETH_PF
> > 
> > from [0] would be a more reliable way to determine, whether we are dealing with
> > a PF?
> > 
> > [0] https://lore.kernel.org/netdev/20191212003344.5571-3-snelson@pensando.io/
> 
> Note that the indicated code was removed from later versions of that
> patchset and never actually made it into the driver.
> See commit fbb39807e9ae ('ionic: support sr-iov operations')
> 
> Also, using is_physfn will still work with no further changes if we ever add
> another PF device id.
> 
> Unless anyone else has a preference, I think this works fine as is.
> 
> sln
>

If you say so, I won't fight :)

Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>

> 
> > 
> > > +             stats->link_down_events = lif->link_down_count;
> > > +}
> > > +
> > >   static int ionic_get_link_ksettings(struct net_device *netdev,
> > >                                    struct ethtool_link_ksettings *ks)
> > >   {
> > > @@ -1074,6 +1083,7 @@ static const struct ethtool_ops ionic_ethtool_ops = {
> > >        .get_regs_len           = ionic_get_regs_len,
> > >        .get_regs               = ionic_get_regs,
> > >        .get_link               = ethtool_op_get_link,
> > > +     .get_link_ext_stats     = ionic_get_link_ext_stats,
> > >        .get_link_ksettings     = ionic_get_link_ksettings,
> > >        .set_link_ksettings     = ionic_set_link_ksettings,
> > >        .get_coalesce           = ionic_get_coalesce,
> > > diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.c b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
> > > index 957027e546b3..6ccc1ea91992 100644
> > > --- a/drivers/net/ethernet/pensando/ionic/ionic_lif.c
> > > +++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.c
> > > @@ -168,6 +168,7 @@ static void ionic_link_status_check(struct ionic_lif *lif)
> > >                }
> > >        } else {
> > >                if (netif_carrier_ok(netdev)) {
> > > +                     lif->link_down_count++;
> > >                        netdev_info(netdev, "Link down\n");
> > >                        netif_carrier_off(netdev);
> > >                }
> > > diff --git a/drivers/net/ethernet/pensando/ionic/ionic_lif.h b/drivers/net/ethernet/pensando/ionic/ionic_lif.h
> > > index c9c4c46d5a16..fd2ea670e7d8 100644
> > > --- a/drivers/net/ethernet/pensando/ionic/ionic_lif.h
> > > +++ b/drivers/net/ethernet/pensando/ionic/ionic_lif.h
> > > @@ -201,6 +201,7 @@ struct ionic_lif {
> > >        u64 hw_features;
> > >        bool registered;
> > >        u16 lif_type;
> > > +     unsigned int link_down_count;
> > >        unsigned int nmcast;
> > >        unsigned int nucast;
> > >        unsigned int nvlans;
> > > --
> > > 2.17.1
> > > 
> > >