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Date:   Tue, 12 Oct 2021 13:17:09 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     Biju Das <biju.das.jz@bp.renesas.com>
Cc:     "David S. Miller" <davem@davemloft.net>,
        Sergey Shtylyov <s.shtylyov@omp.ru>,
        Sergei Shtylyov <sergei.shtylyov@gmail.com>,
        Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>,
        Andrew Lunn <andrew@lunn.ch>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Adam Ford <aford173@gmail.com>,
        Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        "linux-renesas-soc@vger.kernel.org>, Chris Paterson 
        <Chris.Paterson2@renesas.com>, Biju Das <biju.das@bp.renesas.com" 
        <linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH net-next v3 00/14] Add functional support for Gigabit
 Ethernet driver
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On Tue, 12 Oct 2021 18:53:50 +0000 Biju Das wrote:
> > > Yes, you are correct. Sergey, suggested use R-Car RX-HW checksum with
> > > RCSC/RCPT and But the TOE gives either 0x0 or 0xffff as csum output
> > > and feeding this value to skb->csum lead to kernel crash.  
> > 
> > That's quite concerning. Do you have any of the
> > 
> > /proc/sys/kernel/panic_on_io_nmi
> > /proc/sys/kernel/panic_on_oops
> > /proc/sys/kernel/panic_on_rcu_stall
> > /proc/sys/kernel/panic_on_unrecovered_nmi
> > /proc/sys/kernel/panic_on_warn
> > 
> > knobs set? I'm guessing we hit do_netdev_rx_csum_fault() when the checksum
> > is incorrect, but I'm surprised that causes a panic.
> 
> I tested this last week, if I remember correctly It was not panic,
> rather do_netdev_rx_csum_fault. I will recheck and will send you the
> stack trace next time. 

Ah, when you say crash you mean a stack trace appears. The machine does
not crash? That's fine, we don't need to see the trace.