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 <20210218150116.1521-1-marco.wenzel@a-eberle.de>
In-Reply-To: <20210218150116.1521-1-marco.wenzel@a-eberle.de>
From:   George McCollister <george.mccollister@gmail.com>
Date:   Thu, 18 Feb 2021 11:06:12 -0600
Message-ID: <CAFSKS=OpnDK83F6MWCpGDg2pdY-enJyusB5Th1RGvq8UC1WCNQ@mail.gmail.com>
Subject: Re: [PATCH] net: hsr: add support for EntryForgetTime
To:     Marco Wenzel <marco.wenzel@a-eberle.de>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Murali Karicheri <m-karicheri2@ti.com>,
        Taehee Yoo <ap420073@gmail.com>,
        Amol Grover <frextrite@gmail.com>,
        YueHaibing <yuehaibing@huawei.com>,
        Arvid Brodin <Arvid.Brodin@xdin.com>, netdev@vger.kernel.org,
        open list <linux-kernel@vger.kernel.org>
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On Thu, Feb 18, 2021 at 9:01 AM Marco Wenzel <marco.wenzel@a-eberle.de> wrote:
>
> In IEC 62439-3 EntryForgetTime is defined with a value of 400 ms. When a
> node does not send any frame within this time, the sequence number check
> for can be ignored. This solves communication issues with Cisco IE 2000
> in Redbox mode.
>
> Fixes: f421436a591d ("net/hsr: Add support for the High-availability Seamless Redundancy protocol (HSRv0)")
> Signed-off-by: Marco Wenzel <marco.wenzel@a-eberle.de>
> ---
>  net/hsr/hsr_framereg.c | 9 +++++++--
>  net/hsr/hsr_framereg.h | 1 +
>  net/hsr/hsr_main.h     | 1 +
>  3 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/net/hsr/hsr_framereg.c b/net/hsr/hsr_framereg.c
> index 5c97de459905..805f974923b9 100644
> --- a/net/hsr/hsr_framereg.c
> +++ b/net/hsr/hsr_framereg.c
> @@ -164,8 +164,10 @@ static struct hsr_node *hsr_add_node(struct hsr_priv *hsr,
>          * as initialization. (0 could trigger an spurious ring error warning).
>          */
>         now = jiffies;
> -       for (i = 0; i < HSR_PT_PORTS; i++)
> +       for (i = 0; i < HSR_PT_PORTS; i++) {
>                 new_node->time_in[i] = now;
> +               new_node->time_out[i] = now;
> +       }
>         for (i = 0; i < HSR_PT_PORTS; i++)
>                 new_node->seq_out[i] = seq_out;
>
> @@ -411,9 +413,12 @@ void hsr_register_frame_in(struct hsr_node *node, struct hsr_port *port,
>  int hsr_register_frame_out(struct hsr_port *port, struct hsr_node *node,
>                            u16 sequence_nr)
>  {
> -       if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]))
> +       if (seq_nr_before_or_eq(sequence_nr, node->seq_out[port->type]) &&
> +           time_is_after_jiffies(node->time_out[port->type] +
> +           msecs_to_jiffies(HSR_ENTRY_FORGET_TIME)))
>                 return 1;
>
> +       node->time_out[port->type] = jiffies;
>         node->seq_out[port->type] = sequence_nr;
>         return 0;
>  }
> diff --git a/net/hsr/hsr_framereg.h b/net/hsr/hsr_framereg.h
> index 86b43f539f2c..d9628e7a5f05 100644
> --- a/net/hsr/hsr_framereg.h
> +++ b/net/hsr/hsr_framereg.h
> @@ -75,6 +75,7 @@ struct hsr_node {
>         enum hsr_port_type      addr_B_port;
>         unsigned long           time_in[HSR_PT_PORTS];
>         bool                    time_in_stale[HSR_PT_PORTS];
> +       unsigned long           time_out[HSR_PT_PORTS];
>         /* if the node is a SAN */
>         bool                    san_a;
>         bool                    san_b;
> diff --git a/net/hsr/hsr_main.h b/net/hsr/hsr_main.h
> index 7dc92ce5a134..f79ca55d6986 100644
> --- a/net/hsr/hsr_main.h
> +++ b/net/hsr/hsr_main.h
> @@ -21,6 +21,7 @@
>  #define HSR_LIFE_CHECK_INTERVAL                 2000 /* ms */
>  #define HSR_NODE_FORGET_TIME           60000 /* ms */
>  #define HSR_ANNOUNCE_INTERVAL            100 /* ms */
> +#define HSR_ENTRY_FORGET_TIME            400 /* ms */
>
>  /* By how much may slave1 and slave2 timestamps of latest received frame from
>   * each node differ before we notify of communication problem?
> --
> 2.30.0
>

scripts/checkpatch.pl gives errors about DOS line endings but once
that is resolved this looks good. I tested it on an HSR network with
the software implementation and the xrs700x which uses offloading and
everything still works. I don't have a way to force anything on the
HSR network to reuse sequence numbers after 400ms.

Reviewed-by: George McCollister <george.mccollister@gmail.com
Tested-by: George McCollister <george.mccollister@gmail.com