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Subject: Re: [PATCH net-next 0/1] Support for VLAN interface over HSR/PRP
From:   Murali Karicheri <m-karicheri2@ti.com>
To:     <davem@davemloft.net>, <kuba@kernel.org>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <nsekhar@ti.com>,
        <grygorii.strashko@ti.com>
References: <20200901195415.4840-1-m-karicheri2@ti.com>
 <d93fbc54-1721-ebec-39ca-dc8b45e6e534@ti.com>
Message-ID: <15bbf7d2-627b-1d52-f130-5bae7b7889de@ti.com>
Date:   Wed, 2 Sep 2020 18:29:56 -0400
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All,

On 9/2/20 12:14 PM, Murali Karicheri wrote:
> All,
> 
> On 9/1/20 3:54 PM, Murali Karicheri wrote:
>> This series add support for creating VLAN interface over HSR or
>> PRP interface. Typically industrial networks uses VLAN in
>> deployment and this capability is needed to support these
>> networks.
>>
>> This is tested using two TI AM572x IDK boards connected back
>> to back over CPSW  ports (eth0 and eth1).
>>
>> Following is the setup
>>
>>                  Physical Setup
>>                  ++++++++++++++
>>   _______________    (CPSW)     _______________
>>   |              |----eth0-----|               |
>>   |TI AM572x IDK1|             | TI AM572x IDK2|
>>   |______________|----eth1-----|_______________|
>>
>>
>>                  Network Topolgy
>>                  +++++++++++++++
>>
>>                         TI AM571x IDK  TI AM572x IDK
>>
>> 192.168.100.10                 CPSW ports                 192.168.100.20
>>               IDK-1                                        IDK-2
>> hsr0/prp0.100--| 192.168.2.10  |--eth0--| 192.168.2.20 |--hsr0/prp0.100
>>                 |----hsr0/prp0--|        |---hsr0/prp0--|
>> hsr0/prp0.101--|               |--eth1--|              |--hsr0/prp0/101
>>
>> 192.168.101.10                                            192.168.101.20
>>
>> Following tests:-
>>   - create hsr or prp interface and ping the interface IP address
>>     and verify ping is successful.
>>   - Create 2 VLANs over hsr or prp interface on both IDKs (VID 100 and
>>     101). Ping between the IP address of the VLAN interfaces
>>   - Do iperf UDP traffic test with server on one IDK and client on the
>>     other. Do this using 100 and 101 subnet IP addresses
>>   - Dump /proc/net/vlan/{hsr|prp}0.100 and verify frames are transmitted
>>     and received at these interfaces.
>>   - Delete the vlan and hsr/prp interface and verify interfaces are
>>     removed cleanly.
>>
>> Logs for IDK-1 at https://pastebin.ubuntu.com/p/NxF83yZFDX/
>> Logs for IDK-2 at https://pastebin.ubuntu.com/p/YBXBcsPgVK/
>>
>> Murali Karicheri (1):
>>    net: hsr/prp: add vlan support
>>
>>   net/hsr/hsr_device.c  |  4 ----
>>   net/hsr/hsr_forward.c | 16 +++++++++++++---
>>   2 files changed, 13 insertions(+), 7 deletions(-)
>>
> I am not sure if the packet flow is right for this?
> 
> VLAN over HSR frame format is like this.
> 
> <Start of Frame><VLAN tag><HSR Tag><IP><CRC>
> 
> My ifconfig stats shows both hsr and hsr0.100 interfaces receiving
> frames.
> 
> So I did a WARN_ON() in HSR driver before frame is forwarded to upper
> layer.
> 
> a0868495local@uda0868495:~/Projects/upstream-kernel$ git diff
> diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c
> index de21df30b0d9..545a3cd8c71b 100644
> --- a/net/hsr/hsr_forward.c
> +++ b/net/hsr/hsr_forward.c
> @@ -415,9 +415,11 @@ static void hsr_forward_do(struct hsr_frame_info 
> *frame)
>                  }
> 
>                  skb->dev = port->dev;
> -               if (port->type == HSR_PT_MASTER)
> +               if (port->type == HSR_PT_MASTER) {
> +                       if (skb_vlan_tag_present(skb))
> +                               WARN_ON(1);
>                          hsr_deliver_master(skb, port->dev, 
> frame->node_src);
> -               else
> +               } else
>                          hsr_xmit(skb, port, frame);
>          }
>   }
> 
> And I get the trace shown below.
> 
> [  275.125431] WARNING: CPU: 0 PID: 0 at net/hsr/hsr_forward.c:420 
> hsr_forward_skb+0x460/0x564
> [  275.133822] Modules linked in: snd_soc_omap_hdmi snd_soc_ti_sdma 
> snd_soc_core snd_pcm_dmaengine snd_pcm snd_time4
> [  275.199705] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W 
> 5.9.0-rc1-00658-g473e463812c2-dirty #8
> [  275.209573] Hardware name: Generic DRA74X (Flattened Device Tree)
> [  275.215703] [<c011177c>] (unwind_backtrace) from [<c010b6f0>] 
> (show_stack+0x10/0x14)
> [  275.223487] [<c010b6f0>] (show_stack) from [<c055690c>] 
> (dump_stack+0xc4/0xe4)
> [  275.230747] [<c055690c>] (dump_stack) from [<c01386ac>] 
> (__warn+0xc0/0xf4)
> [  275.237656] [<c01386ac>] (__warn) from [<c0138a3c>] 
> (warn_slowpath_fmt+0x58/0xb8)
> [  275.245177] [<c0138a3c>] (warn_slowpath_fmt) from [<c09564bc>] 
> (hsr_forward_skb+0x460/0x564)
> [  275.253657] [<c09564bc>] (hsr_forward_skb) from [<c0955534>] 
> (hsr_handle_frame+0x15c/0x190)
> [  275.262047] [<c0955534>] (hsr_handle_frame) from [<c07c6704>] 
> (__netif_receive_skb_core+0x23c/0xc88)
> [  275.271223] [<c07c6704>] (__netif_receive_skb_core) from [<c07c7180>] 
> (__netif_receive_skb_one_core+0x30/0x74)
> [  275.281266] [<c07c7180>] (__netif_receive_skb_one_core) from 
> [<c07c72a4>] (netif_receive_skb+0x50/0x1c4)
> [  275.290793] [<c07c72a4>] (netif_receive_skb) from [<c071a55c>] 
> (cpsw_rx_handler+0x230/0x308)
> [  275.299272] [<c071a55c>] (cpsw_rx_handler) from [<c0715ee8>] 
> (__cpdma_chan_process+0xf4/0x188)
> [  275.307925] [<c0715ee8>] (__cpdma_chan_process) from [<c0717294>] 
> (cpdma_chan_process+0x3c/0x5c)
> [  275.316754] [<c0717294>] (cpdma_chan_process) from [<c071dd14>] 
> (cpsw_rx_mq_poll+0x44/0x98)
> [  275.325145] [<c071dd14>] (cpsw_rx_mq_poll) from [<c07c8ae0>] 
> (net_rx_action+0xf0/0x400)
> [  275.333185] [<c07c8ae0>] (net_rx_action) from [<c0101370>] 
> (__do_softirq+0xf0/0x3ac)
> [  275.340965] [<c0101370>] (__do_softirq) from [<c013f5ec>] 
> (irq_exit+0xa8/0xe4)
> [  275.348224] [<c013f5ec>] (irq_exit) from [<c0199344>] 
> (__handle_domain_irq+0x6c/0xe0)
> [  275.356093] [<c0199344>] (__handle_domain_irq) from [<c056f8fc>] 
> (gic_handle_irq+0x4c/0xa8)
> [  275.364481] [<c056f8fc>] (gic_handle_irq) from [<c0100b6c>] 
> (__irq_svc+0x6c/0x90)
> [  275.371996] Exception stack(0xc0e01f18 to 0xc0e01f60)
> 
> Shouldn't it show vlan_do_receive() ?
> 
>      if (skb_vlan_tag_present(skb)) {
>          if (pt_prev) {
>              ret = deliver_skb(skb, pt_prev, orig_dev);
>              pt_prev = NULL;
>          }
>          if (vlan_do_receive(&skb))
>              goto another_round;
>          else if (unlikely(!skb))
>              goto out;
>      }
> 
> Thanks
> 

I did an ftrace today and I find vlan_do_receive() is called for the 
incoming frames before passing SKB to hsr_handle_frame(). If someone
can review this, it will help. Thanks.

https://pastebin.ubuntu.com/p/CbRzXjwjR5/

-- 
Murali Karicheri
Texas Instruments