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From: Andrew Lunn <andrew@lunn•ch>
To: Rafa Corvillo <rafael.corvillo@aoifes•com>
Cc: Stephen Hemminger <stephen@networkplumber•org>, netdev@vger•kernel.org
Subject: Re: [ISSUE: sky2 - rx error] Link stops working under heavy traffic load connected to a mv88e6176
Date: Mon, 8 May 2017 14:38:52 +0200	[thread overview]
Message-ID: <20170508123852.GI27709@lunn.ch> (raw)
In-Reply-To: <59105EA3.9030203@aoifes.com>

> >static unsigned sky2_get_rx_threshold(struct sky2_port *sky2)
> >{
> >         unsigned size;
> >
> >         /* Space needed for frame data + headers rounded up */
> >         size = roundup(sky2->netdev->mtu + ETH_HLEN + VLAN_HLEN, 8);
> >
> >         /* Stopping point for hardware truncation */
> >         return (size - 8) / sizeof(u32);
> >}
> >
> >This is not going to be big enough for a frame with a DSA header.
> >
> 
> Then, would be a good fix add 8 bytes to the size variable in this function?

Yes. Also look at the transmit code, is there again a limit based on
the MTU.

> Settings for marvell:
>         Supported ports: [ TP ]
>         Supported link modes:   10baseT/Half 10baseT/Full
>                                 100baseT/Half 100baseT/Full
>                                 1000baseT/Half 1000baseT/Full
>         Supported pause frame use: No
>         Supports auto-negotiation: Yes
>         Advertised link modes:  10baseT/Half 10baseT/Full
>                                 100baseT/Half 100baseT/Full
>                                 1000baseT/Half 1000baseT/Full
>         Advertised pause frame use: No
>         Advertised auto-negotiation: No
>         Speed: 1000Mb/s
>         Duplex: Full
>         Port: Twisted Pair
>         PHYAD: 0
>         Transceiver: internal
>         Auto-negotiation: on
>         MDI-X: Unknown
>         Supports Wake-on: pg
>         Wake-on: d
>         Current message level: 0x000000ff (255)
>                                drv probe link timer ifdown ifup
> rx_err tx_err
>         Link detected: yes
> 

So this suggests there is a real PHY there, and it is
auto-negotiating.

What we cannot see is the status for the PHY it connects to. But since
this PHY has established a link, the other PHY is probably O.K. It is
just a bit unsafe, since you are relying on reset behaviour. There is
nothing in software configuring the second PHY to make it
auto-negotiate.

	Andrew

  reply	other threads:[~2017-05-08 12:38 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-21 12:39 [ISSUE: sky2 - rx error] Link stops working under heavy traffic load connected to a mv88e6176 Rafa Corvillo
2017-04-24  6:45 ` Rafa Corvillo
2017-04-25 15:27 ` Stephen Hemminger
2017-04-27 12:05   ` Rafa Corvillo
2017-04-27 13:04     ` Andrew Lunn
2017-04-28 11:54       ` Rafa Corvillo
2017-04-28 12:22         ` Andrew Lunn
2017-05-08 12:03           ` Rafa Corvillo
2017-05-08 12:38             ` Andrew Lunn [this message]
2017-05-16 10:50               ` Rafa Corvillo
2017-05-16 12:47                 ` Andrew Lunn
2017-05-16 13:09                   ` Rafa Corvillo
2017-05-16 13:21                     ` Andrew Lunn
2017-05-16 15:50                       ` Rafa Corvillo
2017-05-16 15:58                         ` Andrew Lunn
2017-05-16 16:19                           ` Rafa Corvillo
2017-05-26 10:13                             ` Rafa Corvillo
2017-05-31 19:31                               ` Andrew Lunn

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