AW: assert in phylink.c with lan7801 and dp83tc811 since kernel 6.18

[Sven Schuchmann <schuchmann@schleissheimer.de>]

Hello Andrew

> Von: Andrew Lunn <andrew@lunn.ch>
> Gesendet: Mittwoch, 06. Mai 2026 15:15
> An: Sven Schuchmann <schuchmann@schleissheimer.de>
> Cc: netdev@vger.kernel.org <netdev@vger.kernel.org>
> Betreff: Re: assert in phylink.c with lan7801 and dp83tc811 since kernel 6.18
>
> [...]
>
> Please try this patch.
>
>      Andrew

> From ea55645b23092a0de7aa3ab0eaf7bcb73a7fb0e1 Mon Sep 17 00:00:00 2001
> From: Andrew Lunn <andrew@lunn.ch>
> Date: Wed, 6 May 2026 08:10:29 -0500
> Subject: [PATCH] net: usb: lan78xx: Fix cleanup in lan78xx_phy_init
>
> If phylink_connect_phy() fails, phylink_disconnect() should not be
> called. Rather than use lan78xx_phy_uninit() which does too much, add
> the cleanup at the end of the function and only undo what was
> successfully done.
>
> Signed-off-by: Andrew Lunn <andrew@lunn.ch>
>
> ---
>  drivers/net/usb/lan78xx.c | 14 ++++++++------
>  1 file changed, 8 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
> index bcf293ea1bd3..9cfc122d76ef 100644
> --- a/drivers/net/usb/lan78xx.c
> +++ b/drivers/net/usb/lan78xx.c
> @@ -2842,7 +2842,7 @@ static int lan78xx_phy_init(struct lan78xx_net *dev)
>  
>          ret = lan78xx_mac_prepare_for_phy(dev);
>          if (ret < 0)
> -               goto phylink_uninit;
> +               goto destroy_phylink;
>  
>          /* If no PHY is found, set up a fixed link. It is very specific to
>           * the LAN7801 and is used in special cases like EVB-KSZ9897-1 where
> @@ -2852,7 +2852,7 @@ static int lan78xx_phy_init(struct lan78xx_net *dev)
>          if (!phydev) {
>                  ret = lan78xx_set_fixed_link(dev);
>                  if (ret < 0)
> -                       goto phylink_uninit;
> +                       goto destroy_phylink;
>  
>                  /* No PHY found, so set up a fixed link and return early.
>                   * No need to configure PHY IRQ or attach to phylink.
> @@ -2871,17 +2871,19 @@ static int lan78xx_phy_init(struct lan78xx_net *dev)
>          if (ret) {
>                  netdev_err(dev->net, "can't attach PHY to %s, error %pe\n",
>                             dev->mdiobus->id, ERR_PTR(ret));
> -               goto phylink_uninit;
> +               goto destroy_phylink;
>         }
>  
>          ret = lan78xx_configure_leds_from_dt(dev, phydev);
> 
>      if (ret < 0)
> -               goto phylink_uninit;
> +               goto disconnect_phylink;
>  
>          return 0;
>  
> -phylink_uninit:
> -       lan78xx_phy_uninit(dev);
> 
> +disconnect_phylink:
> +       phylink_disconnect_phy(dev->phylink);
> +destroy_phylink:
> +       phylink_destroy(dev->phylink);
> 
>          return ret;
>  }
> --
> 2.53.0

This prevents the crash. I think this is the fix for the RTNL Problem. Thank you!
But as you already said it is not giving me working ethernet. Will answer in another email.

Regards,

   Sven