Dell Sputnik

Bug #1729674
Comment #8

Comment 8 for bug 1729674

Revision history for this message

Mario Limonciello (superm1) wrote on 2017-11-03: Re: [Bug 1729674] Re: TB16 dock ethernet corrupts data with hw checksum silently failing

The asmedia host controller is what the realtek device is hooked up to.
That patch for asmedia host controller was developed specifically because
of problems with Ethernet not working at >100mbps and causing errors in the
syslog. So yeah that patch does help in that regard :(

It's possible that with the bisect you'll find that you'll come down to
that commit and the problem goes away traded for the poor performance
problem. If so that's not ideal, but I guess let's cross that bridge when
we come to it.

On Thu, Nov 2, 2017, 23:00 Dave Chiluk <email address hidden> wrote:

> That one applies pretty exclusively to asmedia devices. I don't see how
> that would affect a realtek device. Either way, I'll try to carve out some
> time to check the mainline kernel and bisect if possible. It's pretty
> straightforward to reproduce. All I've been doing is downloading the an
> ubuntu iso, and checking the md5sum of it. If I have hardware offloading
> on it will not pass the md5sum.
>
> Is it possible that there is an updated firmware for the tb16 dock that I
> may need? Otherwise you might want to contact the chip vendor to get them
> working on this.
>
> On Thu, Nov 2, 2017 at 5:03 PM, Mario Limonciello <email address hidden>
> wrote:
>
> > Going the opposite direction you may or may not have
> > https://github.com/torvalds/linux/commit/9da5a1092b13468839b1a864b126ca
> > cfb72ad016
> > #diff-8e88b7e83565580efd59e852f42341a5
> >
> > That's supposed to be fixing the problems with Ethernet.
> >
> > If you can trivially reproduce this, could you maybe bisect?
> >
> > --
> > You received this bug notification because you are subscribed to the bug
> > report.
> > https://bugs.launchpad.net/bugs/1729674
> >
> > Title:
> > TB16 dock ethernet corrupts data with hw checksum silently failing
> >
> > Status in Dell Sputnik:
> > New
> >
> > Bug description:
> > It looks like TCP rx and tx checksum offloading is broken on the TB16
> > dock's ethernet adapter. For example downloading a large file such as the
> > Ubuntu ISO, and then running an md5sum on it yields the incorrect md5sum.
> > This is because
> > rx-checksumming: on
> > tx-checksumming: on
> > and both set to on by default.
> >
> > Running sudo ethtool -K <TB16 eth device> tx off rx off, allows the
> > download to complete correctly. This is very bad since this can cause
> > very bad untrustworthy behavior.
> >
> > This was conducted using an Dell Precision 5520 on Ubuntu 16.04+linux-
> > generic-hwe-16.04-edge.
> >
> > Thank you
> >
> > To manage notifications about this bug go to:
> > https://bugs.launchpad.net/dell-sputnik/+bug/1729674/+subscriptions
> >
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1729674
>
> Title:
> TB16 dock ethernet corrupts data with hw checksum silently failing
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/dell-sputnik/+bug/1729674/+subscriptions
>

On Thu, Nov 2, 2017, 23:00 Dave Chiluk <1729674@bugs.launchpad.net> wrote:

> That one applies pretty exclusively to asmedia devices.  I don't see how
> that would affect a realtek device.  Either way, I'll try to carve out some
> time to check the mainline kernel and bisect if possible.  It's pretty
> straightforward to reproduce.  All I've been doing is downloading the an
> ubuntu iso, and checking the md5sum of it.  If I have hardware offloading
> on it will not pass the md5sum.
>
> Is it possible that there is an updated firmware for the tb16 dock that I
> may need?  Otherwise you might want to contact the chip vendor to get them
> working on this.
>
> On Thu, Nov 2, 2017 at 5:03 PM, Mario Limonciello <superm1@ubuntu.com>
> wrote:
>
> > Going the opposite direction you may or may not have
> > https://github.com/torvalds/linux/commit/9da5a1092b13468839b1a864b126ca
> > cfb72ad016
> > #diff-8e88b7e83565580efd59e852f42341a5
> >
> > That's supposed to be fixing the problems with Ethernet.
> >
> > If you can trivially reproduce this, could you maybe bisect?
> >
> > --
> > You received this bug notification because you are subscribed to the bug
> > report.
> > https://bugs.launchpad.net/bugs/1729674
> >
> > Title:
> >   TB16 dock ethernet corrupts data with hw checksum silently failing
> >
> > Status in Dell Sputnik:
> >   New
> >
> > Bug description:
> >   It looks like TCP  rx and tx checksum offloading is broken on the TB16
> > dock's ethernet adapter. For example downloading a large file such as the
> > Ubuntu ISO, and then running an md5sum on it yields the incorrect md5sum.
> > This is because
> >   rx-checksumming: on
> >   tx-checksumming: on
> >   and both set to on by default.
> >
> >   Running sudo ethtool -K <TB16 eth device> tx off rx off, allows the
> >   download to complete correctly.  This is very bad since this can cause
> >   very bad untrustworthy behavior.
> >
> >   This was conducted using an Dell Precision 5520 on Ubuntu 16.04+linux-
> >   generic-hwe-16.04-edge.
> >
> >   Thank you
> >
> > To manage notifications about this bug go to:
> > https://bugs.launchpad.net/dell-sputnik/+bug/1729674/+subscriptions
> >
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1729674
>
> Title:
>   TB16 dock ethernet corrupts data with hw checksum silently failing
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/dell-sputnik/+bug/1729674/+subscriptions
>