From: Eric Dumazet <eric.dumazet@gmail.com>
To: RENARD Pierre-Francois <pfrenard@gmail.com>,
nsaenzjulienne@suse.de, woojung.huh@microchip.com,
UNGLinuxDriver@microchip.com, netdev@vger.kernel.org,
linux-usb@vger.kernel.org, stefan.wahren@i2se.com
Subject: Re: [RPI 3B+ / TSO / lan78xx ]
Date: Tue, 7 Jan 2020 09:04:23 -0800 [thread overview]
Message-ID: <863777f2-3a7b-0736-d0a4-d9966bea3f96@gmail.com> (raw)
In-Reply-To: <78b94ba2-9a87-78bb-8916-e6ef5a0668ae@gmail.com>
On 1/7/20 5:32 AM, RENARD Pierre-Francois wrote:
>
> Hello all
>
> I am facing an issue related to Raspberry PI 3B+ and onboard ethernet card.
>
> When doing a huge transfer (more than 1GB) in a row, transfer hanges and failed after a few minutes.
>
>
> I have two ways to reproduce this issue
>
>
> using NFS (v3 or v4)
>
> dd if=/dev/zero of=/NFSPATH/file bs=4M count=1000 status=progress
>
>
> we can see that at some point dd hangs and becomes non interrutible (no way to ctrl-c it or kill it)
>
> after afew minutes, dd dies and a bunch of NFS server not responding / NFS server is OK are seens into the journal
>
>
> Using SCP
>
> dd if=/dev/zero of=/tmp/file bs=4M count=1000
>
> scp /tmp/file user@server:/directory
>
>
> scp hangs after 1GB and after a few minutes scp is failing with message "client_loop: send disconnect: Broken pipe lostconnection"
>
>
>
>
> It appears, this is a known bug relatted to TCP Segmentation Offload & Selective Acknowledge.
>
> disabling this TSO (ethtool -K eth0 tso off & ethtool -K eth0 gso off) solves the issue.
>
> A patch has been created to disable the feature by default by the raspberry team and is by default applied wihtin raspbian.
>
> comment from the patch :
>
> /* TSO seems to be having some issue with Selective Acknowledge (SACK) that
> * results in lost data never being retransmitted.
> * Disable it by default now, but adds a module parameter to enable it for
> * debug purposes (the full cause is not currently understood).
> */
>
>
> For reference you can find
>
> a link to the issue I created yesterday : https://github.com/raspberrypi/linux/issues/3395
>
> links to raspberry dev team : https://github.com/raspberrypi/linux/issues/2482 & https://github.com/raspberrypi/linux/issues/2449
>
>
>
> If you need me to test things, or give you more informations, I ll be pleased to help.
>
I doubt TSO and SACK have a serious generic bug like that.
Most likely the TSO implementation on the driver/NIC has a bug .
Anyway you do not provide a kernel version, I am not sure what you expect from us.
next prev parent reply other threads:[~2020-01-07 17:04 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <5267da21-8f12-2750-c0c5-4ed31b03833b@gmail.com>
2020-01-07 13:32 ` [RPI 3B+ / TSO / lan78xx ] RENARD Pierre-Francois
2020-01-07 17:04 ` Eric Dumazet [this message]
2020-01-07 17:21 ` Eric Dumazet
2020-01-07 17:30 ` Stefan Wahren
2020-01-07 18:06 ` Eric Dumazet
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