Aw: Re: Re: [PATCH v2] net: mtk_sgmii: implement mtk_pcs_ops

[Frank Wunderlich]

> Gesendet: Freitag, 21. Oktober 2022 um 20:31 Uhr
> Von: "Russell King (Oracle)" <linux@xxxxxxxxxxxxxxx>

> On Fri, Oct 21, 2022 at 07:47:47PM +0200, Frank Wunderlich wrote:
> > > Gesendet: Freitag, 21. Oktober 2022 um 11:06 Uhr
> > > Von: "Russell King (Oracle)" <linux@xxxxxxxxxxxxxxx>

> > > Looking at SGMSYS_PCS_CONTROL_1, this is actually the standard BMCR in
> > > the low 16 bits, and BMSR in the upper 16 bits, so:
> > >
> > > At address 4, I'd expect the PHYSID.
> > > At address 8, I'd expect the advertisement register in the low 16 bits
> > > and the link partner advertisement in the upper 16 bits.
> > >
> > > Can you try an experiment, and in mtk_sgmii_init() try accessing the
> > > regmap at address 0, 4, and 8 and print their contents please?
> >
> > is this what you want to see?

> > [    1.083359] dev: 0 offset:0 0x840140
> > [    1.083376] dev: 0 offset:4 0x4d544950
> > [    1.086955] dev: 0 offset:8 0x1
> > [    1.090697] dev: 1 offset:0 0x81140
> > [    1.093866] dev: 1 offset:4 0x4d544950
> > [    1.097342] dev: 1 offset:8 0x1
>
> Thanks. Decoding these...
>
> dev 0:
>  BMCR: fixed, full duplex, 1000Mbps, !autoneg
>  BMSR: link up
>  Phy ID: 0x4d54 0x4950
>  Advertise: 0x0001 (which would correspond with the MAC side of SGMII)
>  Link partner: 0x0000 (no advertisement received, but we're not using
>     negotiation.)
>
> dev 1:
>  BMCR: autoneg (full duplex, 1000Mbps - both would be ignored)
>  BMSR: able to do autoneg, no link
>  Phy ID: 0x4d54 0x4950
>  Advertise: 0x0001 (same as above)
>  Link partner: 0x0000 (no advertisement received due to no link)
>
> Okay, what would now be interesting is to see how dev 1 behaves when
> it has link with a 1000base-X link partner that is advertising
> properly. If this changes to 0x01e0 or similar (in the high 16-bits
> of offset 8) then we definitely know that this is an IEEE PHY register
> set laid out in memory, and we can program the advertisement and read
> the link partner's abilities.

added register-read on the the new get_state function too

on bootup it is now a bit different

[    1.086283] dev: 0 offset:0 0x40140 #was previously 0x840140
[    1.086301] dev: 0 offset:4 0x4d544950
[    1.089795] dev: 0 offset:8 0x1
[    1.093584] dev: 1 offset:0 0x81140
[    1.096716] dev: 1 offset:4 0x4d544950
[    1.100191] dev: 1 offset:8 0x1

root@bpi-r3:~# ip link set eth1 up
[  172.037519] mtk_soc_eth 15100000.ethernet eth1: configuring for inband/1000base-x link mode
root@bpi-r3:~#
[  172.102949] offset:0 0x40140 #still same value
[  172.102964] offset:4 0x4d544950
[  172.105842] offset:8 0x1
[  172.108992] mtk_soc_eth 15100000.ethernet eth1: Link is Up - 1Gbps/Unknown - flow control off
[  172.120058] IPv6: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready

so no change on link up

maybe ethtool-output is interesting

root@bpi-r3:~# ethtool -m eth1
        Identifier                                : 0x03 (SFP)
        Extended identifier                       : 0x04 (GBIC/SFP defined by 2-wire interface ID)
        Connector                                 : 0x07 (LC)
        Transceiver codes                         : 0x00 0x00 0x00 0x01 0x00 0x00 0x00 0x00 0x00
        Transceiver type                          : Ethernet: 1000BASE-SX
        Encoding                                  : 0x01 (8B/10B)
        BR, Nominal                               : 1300MBd
        Rate identifier                           : 0x00 (unspecified)
        Length (SMF,km)                           : 0km
        Length (SMF)                              : 0m
        Length (50um)                             : 550m
        Length (62.5um)                           : 270m
        Length (Copper)                           : 0m
        Length (OM3)                              : 0m
        Laser wavelength                          : 850nm
        Vendor name                               : OEM
        Vendor OUI                                : 00:90:65
        Vendor PN                                 : GLC-SX-MMD     _
        Vendor rev                                : _e
        Option values                             : 0x00 0x1a
        Option                                    : RX_LOS implemented
        Option                                    : TX_FAULT implemented
        Option                                    : TX_DISABLE implemented
        BR margin, max                            : 0%
        BR margin, min                            : 0%
        Vendor SN                                 : CSCGE1M14134
        Date code                                 : 220120
        Optical diagnostics support               : Yes
        Laser bias current                        : 3.634 mA
        Laser output power                        : 0.3181 mW / -4.97 dBm
        Receiver signal average optical power     : 0.3444 mW / -4.63 dBm
        Module temperature                        : 35.32 degrees C / 95.58 degrees F
        Module voltage                            : 3.3101 V
        Alarm/warning flags implemented           : Yes
        Laser bias current high alarm             : Off
        Laser bias current low alarm              : Off
        Laser bias current high warning           : Off
        Laser bias current low warning            : Off
        Laser output power high alarm             : Off
        Laser output power low alarm              : Off
        Laser output power high warning           : Off
        Laser output power low warning            : Off
        Module temperature high alarm             : Off
        Module temperature low alarm              : Off
        Module temperature high warning           : Off
        Module temperature low warning            : Off
        Module voltage high alarm                 : Off
        Module voltage low alarm                  : Off
        Module voltage high warning               : Off
        Module voltage low warning                : Off
        Laser rx power high alarm                 : Off
        Laser rx power low alarm                  : Off
        Laser rx power high warning               : Off
        Laser rx power low warning                : Off
        Laser bias current high alarm threshold   : 100.000 mA
        Laser bias current low alarm threshold    : 0.000 mA
        Laser bias current high warning threshold : 90.000 mA
        Laser bias current low warning threshold  : 0.100 mA
        Laser output power high alarm threshold   : 1.2589 mW / 1.00 dBm
        Laser output power low alarm threshold    : 0.0501 mW / -13.00 dBm
        Laser output power high warning threshold : 0.7943 mW / -1.00 dBm
        Laser output power low warning threshold  : 0.0631 mW / -12.00 dBm
        Module temperature high alarm threshold   : 90.00 degrees C / 194.00 degrees F
        Module temperature low alarm threshold    : -45.00 degrees C / -49.00 degrees F
        Module temperature high warning threshold : 85.00 degrees C / 185.00 degrees F
        Module temperature low warning threshold  : -40.00 degrees C / -40.00 degrees F
        Module voltage high alarm threshold       : 3.8000 V
        Module voltage low alarm threshold        : 2.7000 V
        Module voltage high warning threshold     : 3.7000 V
        Module voltage low warning threshold      : 2.8000 V
        Laser rx power high alarm threshold       : 0.7943 mW / -1.00 dBm
        Laser rx power low alarm threshold        : 0.0079 mW / -21.02 dBm
        Laser rx power high warning threshold     : 0.5012 mW / -3.00 dBm
        Laser rx power low warning threshold      : 0.0126 mW / -19.00 dBm
root@bpi-r3:~# ethtool eth1
[  295.755349] offset:0 0x40140
[  295.755368] offset:4 0x4d544950
Settings for eth[  295.758247] offset:8 0x1
1:
        Supported p[  295.761551] offset:0 0x40140
[  295.765446] offset:4 0x4d544950

        Supported link modes:   1000baseX/Full
        Supported pause frame use: Symmetric Receive-only
        Supports auto-negotiation: Yes
        Supported FEC modes: Not reported
        Advertised link modes:  1000baseX/Full
        Advertised pause frame use: Symmetric Receive-only
        Advertised auto-negotiation: Yes
        Advertised FEC modes: Not reported
        Speed: 1000Mb/s
        Duplex: Unknown! (255)
        Auto-negotiation: on
        Port: FIBRE
        PHYAD: 0
        Transceiver: internal
        Current message level: 0x000000ff (255)
                               drv probe link timer ifdown ifup rx_err tx_err
        Link detected: yes


> At that point, we should try programming the low 16-bits of offset 8
> to see whether that advertisement makes it to the far end of the link.

have only my switch on the other side where i imho cannot read out these advertising. and programming to which values at which point (in the get-state callback to be done on link-up)?

> It would be well worth trying to work this out, because it will then
> vastly improve the knowledge of this hardware, and improve the
> driver no end.
>
> Is this something you could investigate please?

regards Frank