Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Sat, 22 Oct 2022 18:05:43 +0100
From:   "Russell King (Oracle)" <linux@armlinux.org.uk>
To:     Frank Wunderlich <frank-w@public-files.de>
Cc:     Frank Wunderlich <linux@fw-web.de>,
        linux-mediatek@lists.infradead.org,
        Alexander Couzens <lynxis@fe80.eu>,
        Felix Fietkau <nbd@nbd.name>, John Crispin <john@phrozen.org>,
        Sean Wang <sean.wang@mediatek.com>,
        Mark Lee <Mark-MC.Lee@mediatek.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        netdev@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: Re: Re: Re: [PATCH v2] net: mtk_sgmii: implement mtk_pcs_ops
Message-ID: <Y1Qi55IwJZulL1X/@shell.armlinux.org.uk>
References: <Y1F0pSrJnNlYzehq@shell.armlinux.org.uk>
 <02A54E45-2084-440A-A643-772C0CC9F988@public-files.de>
 <Y1JhEWU5Ac6kd2ne@shell.armlinux.org.uk>
 <trinity-e60759de-3f0f-4b1e-bc0f-b33c4f8ac201-1666374467573@3c-app-gmx-bap55>
 <Y1LlnMdm8pGVXC6d@shell.armlinux.org.uk>
 <trinity-b567c57e-b87f-4fe8-acf7-5c9020f85aed-1666381956560@3c-app-gmx-bap55>
 <Y1MO6cyuVtFxTGuP@shell.armlinux.org.uk>
 <9BC397B2-3E0B-4687-99E5-B15472A1762B@fw-web.de>
 <Y1Ozp2ASm2Y+if3Q@shell.armlinux.org.uk>
 <trinity-4470b00b-771b-466e-9f3a-a3df72758208-1666435920485@3c-app-gmx-bs49>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <trinity-4470b00b-771b-466e-9f3a-a3df72758208-1666435920485@3c-app-gmx-bs49>
Sender: Russell King (Oracle) <linux@armlinux.org.uk>
Precedence: bulk

On Sat, Oct 22, 2022 at 12:52:00PM +0200, Frank Wunderlich wrote:
> > Gesendet: Samstag, 22. Oktober 2022 um 11:11 Uhr
> > Von: "Russell King (Oracle)" <linux@armlinux.org.uk>
> 
> > Please try this untested patch, which should setup the PCS to perform
> > autonegotiation when using in-band mode for 1000base-X, write the
> > correct to offset 8, and set the link timer correctly.
> 
> hi,
> 
> this patch breaks connectivity at least on the sfp-port (eth1).
> 
> root@bpi-r3:~# ip link set eth1 up
> [   65.457521] mtk_soc_eth 15100000.ethernet eth1: configuring for inband/1000base-x link mode
> root@bpi-r3:~# [   65.522936] offset:0 0x2c1140
> [   65.522950] offset:4 0x4d544950
> [   65.525914] offset:8 0x40e041a0
> [   65.529064] mtk_soc_eth 15100000.ethernet eth1: Link is Up - 1Gbps/Unknown - flow control off
> [   65.540733] IPv6: ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready
> 
> root@bpi-r3:~# ip a a 192.168.0.19/24 dev eth1
> root@bpi-r3:~# ip r a default via 192.168.0.10
> root@bpi-r3:~# iperf3 -c 192.168.0.21 #ping does not work too
> iperf3: error - unable to send control message: Bad file descriptor
> root@bpi-r3:~# ethtool eth1
> [  177.346183] offset:0 0x2c1140
> [  177.346202] offset:4 0x4d544950
> Settings for eth[  177.349168] offset:8 0x40e041a0
> 1:
>         Supported p[  177.352477] offset:0 0x2c1140
> [  177.356952] 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
> root@bpi-r3:~#
> 
> from sgmii_init
> [    1.091796] dev: 1 offset:0 0x81140
> [    1.094977] dev: 1 offset:4 0x4d544950
> [    1.098456] dev: 1 offset:8 0x1
> ...
> pcs_get_state
> [   65.522936] offset:0 0x2c1140
> [   65.522950] offset:4 0x4d544950
> [   65.525914] offset:8 0x40e041a0
> [  177.346183] offset:0 0x2c1140
> [  177.346202] offset:4 0x4d544950
> [  177.349168] offset:8 0x40e041a0
> [  177.352477] offset:0 0x2c1140
> [  177.356952] offset:4 0x4d544950

Hi,

Thanks. Well, the results suggest that the register at offset 8 is
indeed the advertisement and link-partner advertisement register. So
we have a bit of progress and a little more understanding of this
hardware.

Do you know if your link partner also thinks the link is up?

What I notice is:

mtk_soc_eth 15100000.ethernet eth1: Link is Up - 1Gbps/Unknown - flow control off

The duplex is "unknown" which means you're not filling in the
state->duplex field in your pcs_get_state() function. Given the
link parter adverisement is 0x00e0, this means the link partner
supports PAUSE, 1000base-X/Half and 1000base-X/Full. The resolution
is therefore full duplex, so can we hack that in to your
pcs_get_state() so we're getting that right for this testing please?

Now, I'm wondering what SGMII_IF_MODE_BIT0 and SGMII_IF_MODE_BIT5 do
in the SGMSYS_SGMII_MODE register. Does one of these bits set the
format for the 16-bit control word that's used to convey the
advertisements. I think the next step would be to play around with
these and see what effect setting or clearing these bits has -
please can you give that a go?

Thanks.

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!