Comment 62 for bug 1729674

Revision history for this message
Georgi Boiko (pandasauce) wrote :

Update to my October post in LP#1667750 which turned out to be a separate issue (1Gbps mode dropouts) on the same adapter.

Dell Precision 5520 and BIOS 1.7 using TB16. This is on Ubuntu 16.04.3, kernel 4.13.0

The issue is still present. I tried limiting the bandwidth using `ethtool -s eth0 speed 100 duplex full autoneg on` and also as described in this blog post: http://mark.koli.ch/slowdown-throttle-bandwidth-linux-network-interface and it *seems* to be making the issue less apparent, but still present.

$ for i in 1 2 3 4; do curl -s http://old-releases.ubuntu.com/releases/17.04/ubuntu-17.04-server-amd64.img -o $i.iso; md5sum $i.iso; done
2641b55ed2e203861fb6f642bb05b8f7 1.iso
63f41e8b8e4e5ad1909637dbd2efd849 2.iso
^C%

$ sudo ethtool -s eth0 speed 100 duplex full autoneg on

$ for i in 1 2 3 4; do curl -s http://old-releases.ubuntu.com/releases/17.04/ubuntu-17.04-server-amd64.img -o $i.iso; md5sum $i.iso; done
4672ce371fb3c1170a9e71bc4b2810b9 1.iso
4672ce371fb3c1170a9e71bc4b2810b9 2.iso
4672ce371fb3c1170a9e71bc4b2810b9 3.iso
4672ce371fb3c1170a9e71bc4b2810b9 4.iso

$ for i in 1 2 3 4; do curl -s http://old-releases.ubuntu.com/releases/17.04/ubuntu-17.04-server-amd64.img -o $i.iso; md5sum $i.iso; done
ed13e9c6c45f027f686000eccce42254 1.iso
4672ce371fb3c1170a9e71bc4b2810b9 2.iso
^C%

Next, I tried disabling offloading as described in LP#1667750. Keep in mind, the device still needs to be in 100Mbps mode or you will experience dropouts in addition to any packet corruption issues that you may run into.

$ sudo ethtool --offload eth0 tx off
Actual changes:
tx-checksumming: off
    tx-checksum-ipv4: off
    tx-checksum-ipv6: off
tcp-segmentation-offload: off
    tx-tcp-segmentation: off [requested on]
    tx-tcp6-segmentation: off [requested on]

$ sudo ethtool --offload eth0 rx off

$ for i in 1 2 3 4 5 6; do curl -s http://old-releases.ubuntu.com/releases/17.04/ubuntu-17.04-server-amd64.img -o $i.iso; md5sum $i.iso; done
4672ce371fb3c1170a9e71bc4b2810b9 1.iso
4672ce371fb3c1170a9e71bc4b2810b9 2.iso
4672ce371fb3c1170a9e71bc4b2810b9 3.iso
4672ce371fb3c1170a9e71bc4b2810b9 4.iso
4672ce371fb3c1170a9e71bc4b2810b9 5.iso
4672ce371fb3c1170a9e71bc4b2810b9 6.iso

I left it to run over lunch at 25 loops to be sure and it's working fine. This weekend I may be able to test this on a 2017 XPS 9560 (non-DE) too.

Thanks for the workaround and looking forward to the patch making it to Ubuntu repos.