[PATCH v3 2/4] kernel: vrx518_tc: fix ADSL/ATM operation

[Hauke Mehrtens]

On 1/12/25 15:09, Sergey Ryazanov wrote:
> ATM TC layer have some issues which effectively prevent VRX518 from
> being used as ADSL modem. Specifically, there one crash during the ATM
> layer configuration and wrong PVC ID selection on packet receiving what
> breaks RX path. Fix both of the issues. Make subif iface registration
> optional to prevent the crash (see more details in the new patch) and
> update the hardcoded PVC ID to match the first allocated channel.
> 
> Run tested with FRITZ!Box 7530.
> 
> Fixes: 474bbe23b7 ("kernel: add Intel/Lantiq VRX518 TC driver")
> Reported-and-tested-by: nebibigon93 at yandex.ru
> Signed-off-by: Sergey Ryazanov <ryazanov.s.a at gmail.com>
> ---
>   .../lantiq/vrx518_tc/patches/100-compat.patch |  2 +-
>   ...tm_tc-fix-crash-on-subif_reg-absence.patch | 75 +++++++++++++++++++
>   2 files changed, 76 insertions(+), 1 deletion(-)
>   create mode 100644 package/kernel/lantiq/vrx518_tc/patches/207-dcdp-atm_tc-fix-crash-on-subif_reg-absence.patch
> 
> diff --git a/package/kernel/lantiq/vrx518_tc/patches/100-compat.patch b/package/kernel/lantiq/vrx518_tc/patches/100-compat.patch
> index d04c1ed5df..81e32369ba 100644
> --- a/package/kernel/lantiq/vrx518_tc/patches/100-compat.patch
> +++ b/package/kernel/lantiq/vrx518_tc/patches/100-compat.patch
> @@ -166,7 +166,7 @@
>    
>   -	return (skb->DW0 >> 3) & 0xF;
>   +// 	return (skb->DW0 >> 3) & 0xF;
> -+	return 1;
> ++	return 0;	/* We use only one connection for now, so return the first connection id */
>    }
>    
>    static int atm_get_qid_by_vcc(struct net_device *dev, struct sk_buff *skb,

Do we have the information atm_get_pvc_id() should return somewhere else 
in the skb?

The DW0 attribute is the patched in DMA descriptor used to transfer this 
packet.

Hauke