Re: [PATCH 12/15] habanalabs/gaudi: add debugfs entries for the NIC

[Jakub Kicinski]

On Thu, 10 Sep 2020 23:10:47 +0300 Oded Gabbay wrote:
> On Thu, Sep 10, 2020 at 11:01 PM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
> >
> > On Thu, 10 Sep 2020 19:11:23 +0300 Oded Gabbay wrote:  
> > > From: Omer Shpigelman <oshpigelman@xxxxxxxxx>
> > >
> > > Add several debugfs entries to help us debug the NIC engines and ports and
> > > also the communication layer of the DL training application that use them.
> > >
> > > There are eight new entries. Detailed description is in the documentation
> > > file but here is a summary:
> > >
> > > - nic_mac_loopback: enable mac loopback mode per port
> > > - nic_ports_status: print physical connection status per port
> > > - nic_pcs_fail_time_frame: configure windows size for measuring pcs
> > >                            failures
> > > - nic_pcs_fail_threshold: configure pcs failures threshold for
> > >                           reconfiguring the link
> > > - nic_pam4_tx_taps: configure PAM4 TX taps
> > > - nic_polarity: configure polarity for NIC port lanes
> > > - nic_check_link: configure whether to check the PCS link periodically
> > > - nic_phy_auto_neg_lpbk: enable PHY auto-negotiation loopback
> > >
> > > Signed-off-by: Omer Shpigelman <oshpigelman@xxxxxxxxx>
> > > Reviewed-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>
> > > Signed-off-by: Oded Gabbay <oded.gabbay@xxxxxxxxx>  
> >
> > debugfs configuration interfaces are not acceptable in netdev.  
> 
> no problem, but can we have only these two entries:
> > - nic_mac_loopback: enable mac loopback mode per port
> > - nic_ports_status: print physical connection status per port  
> 
> nic_ports_status is print only (not configuration).

Doesn't seem like this one shows any more information than can be
queried with ethtool, right?

> nic_mac_loopback
> is to set a port to loopback mode and out of it. It's not really
> configuration but rather a mode change.

What is this loopback for? Testing?