From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cong Wang <xiyou.wangcong@gmail.com>
Subject: Re: Latest net-next kernel 4.19.0+
Date: Tue, 30 Oct 2018 10:32:39 -0700
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Cc: =?UTF-8?Q?Pawe=C5=82_Staszewski?= <pstaszewski@itcare.pl>,
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        Linux Kernel Network Developers <netdev@vger.kernel.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
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On Tue, Oct 30, 2018 at 7:16 AM Eric Dumazet <eric.dumazet@gmail.com> wrote=
:
>
>
>
> On 10/30/2018 01:09 AM, Pawe=C5=82 Staszewski wrote:
> >
> >
> > W dniu 30.10.2018 o 08:29, Eric Dumazet pisze:
> >>
> >> On 10/29/2018 11:09 PM, Dimitris Michailidis wrote:
> >>
> >>> Indeed this is a bug. I would expect it to produce frequent errors
> >>> though as many odd-length
> >>> packets would trigger it. Do you have RXFCS? Regardless, how
> >>> frequently do you see the problem?
> >>>
> >> Old kernels (before 88078d98d1bb) were simply resetting ip_summed to C=
HECKSUM_NONE
> >>
> >> And before your fix (commit d55bef5059dd057bd), mlx5 bug was canceling=
 the bug you fixed.
> >>
> >> So we now need to also fix mlx5.
> >>
> >> And of course use skb_header_pointer() in mlx5e_get_fcs() as I mention=
ed earlier,
> >> plus __get_unaligned_cpu32() as you hinted.
> >>
> >>
> >>
> >>
> >
> > No RXFCS


Same with Pawel, RXFCS is disabled by default.


> >
> > And this trace is rly frequently like once per 3/4 seconds
> > like below:
> > [28965.776864] vlan1490: hw csum failure
>
> Might be vlan related.

Unlike Pawel's case, we don't use vlan at all, maybe this is why we see
it much less frequently than Pawel.

Also, it is probably not specific to mlx5, as there is another report which
is probably a non-mlx5 driver.

Thanks.