linux-kernel - Re: [RFC PATCH 0/1] net: phy: skip autoneg of ethernet(fec) on network boot

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Message-Id: <20180717.104733.1408380842449139305.kimoto@cybertrust.co.jp>
Date:   Tue, 17 Jul 2018 10:47:33 +0900 (JST)
From:   Masahiko KIMOTO <masahiko.kimoto@...ertrust.co.jp>
To:     andrew@...n.ch
Cc:     f.fainelli@...il.com, fugang.duan@....com, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org, hiraku.toyooka@...ertrust.co.jp
Subject: Re: [RFC PATCH 0/1] net: phy: skip autoneg of ethernet(fec) on
 network boot

  >   > You said that the PHY is being configured 3 times, and might be doing
  >   > auto-neg three times. Often a phy will not actually perform auto-neg,
  >   > or do it much faster, if the advertised bits do not change with each
  >   > re-configuration.
  >   > 
  >   > So check how u-boot is configuring what is advertised, and look at
  >   > what Linux is configuring. In particularly, look at the pause
  >   > configuration. If pause is configured different in u-boot and Linux,
  >   > try to make it the same. Things might go faster than.
  > 
  > Thank you.
  > 
  > I'll try to check out u-boot side by mii command and Linux(server)
  > side by ethtool.

PHY setting in u-boot and after booting Linux is as follows;

We may avoid second and third auto-neg if both settings in u-boot and
in linux make same value, right?

---------------------------------------------------------------------------
=> mii dump 1 4
4.     (11e1)                 -- Autonegotiation advertisement register --
  (8000:0000) 4.15    =     0    next page able
  (4000:0000) 4.14    =     0    (reserved)
  (2000:0000) 4.13    =     0    remote fault
  (1000:1000) 4.12    =     1    (reserved)
  (0800:0000) 4.11    =     0    asymmetric pause
  (0400:0000) 4.10    =     0    pause enable
  (0200:0000) 4. 9    =     0    100BASE-T4 able
  (0100:0100) 4. 8    =     1    100BASE-TX full duplex able
  (0080:0080) 4. 7    =     1    100BASE-TX able
  (0040:0040) 4. 6    =     1    10BASE-T   full duplex able
  (0020:0020) 4. 5    =     1    10BASE-T   able
  (001f:0001) 4. 4- 0 =     1    selector = IEEE 802.3


=> mii dump 1 5
5.     (dd01)                 -- Autonegotiation partner abilities register --
  (8000:8000) 5.15    =     1    next page able
  (4000:4000) 5.14    =     1    acknowledge
  (2000:0000) 5.13    =     0    remote fault
  (1000:1000) 5.12    =     1    (reserved)
  (0800:0800) 5.11    =     1    asymmetric pause able
  (0400:0400) 5.10    =     1    pause able
  (0200:0000) 5. 9    =     0    100BASE-T4 able
  (0100:0100) 5. 8    =     1    100BASE-X full duplex able
  (0080:0000) 5. 7    =     0    100BASE-TX able
  (0040:0000) 5. 6    =     0    10BASE-T full duplex able
  (0020:0000) 5. 5    =     0    10BASE-T able
  (001f:0001) 5. 4- 0 =     1    selector = IEEE 802.3

---------------------------------------------------------------------------
root@...6qdlsabresd:~# ethtool eth0
Settings for eth0:
        Supported ports: [ TP MII ]
        Supported link modes:   10baseT/Half 10baseT/Full 
                                100baseT/Half 100baseT/Full 
                                1000baseT/Full 
        Supported pause frame use: Symmetric
        Supports auto-negotiation: Yes
        Advertised link modes:  10baseT/Half 10baseT/Full 
                                100baseT/Half 100baseT/Full 
                                1000baseT/Full 
        Advertised pause frame use: Symmetric
        Advertised auto-negotiation: Yes
        Link partner advertised link modes:  100baseT/Full 
                                             1000baseT/Full 
        Link partner advertised pause frame use: Symmetric Receive-only
        Link partner advertised auto-negotiation: Yes
        Speed: 1000Mb/s
        Duplex: Full
        Port: MII
        PHYAD: 1
        Transceiver: internal
        Auto-negotiation: on
        Supports Wake-on: d
        Wake-on: d
        Link detected: yes

root@...6qdlsabresd:~# ethtool -a eth0
Pause parameters for eth0:
Autonegotiate:  on
RX:             off
TX:             off
RX negotiated:  on
TX negotiated:  on

---------------------------------------------------------------------------

---------------------------------------------------------------------------
Masahiko KIMOTO,Ph.D. / Cybertrust Japan Co., Ltd. 
mail: masahiko.kimoto@...ertrust.co.jp
web: https://www.cybertrust.co.jp/ https://www.miraclelinux.com/