Re: thunderx sgmii interface hang

On Mon, Dec 18, 2017 at 01:53:47PM -0800, Tim Harvey wrote:

On Wed, Dec 13, 2017 at 11:43 AM, Andrew Lunn [off-list ref] wrote:

quoted

quoted

The nic appears to work fine (pings, TCP etc) up until a performance
test is attempted.
When an iperf bandwidth test is attempted the nic ends up in a state
where truncated-ip packets are being sent out (per a tcpdump from
another board):

Hi Tim

Are pause frames supported? Have you tried turning them off?

Can you reproduce the issue with UDP? Or is it TCP only?

Andrew,

Pause frames don't appear to be supported yet and the issue occurs
when using UDP as well as TCP. I'm not clear what the best way to
troubleshoot this is.

Hi Tim

Is pause being negotiated? In theory, it should not be. The PHY should
not offer it, if the MAC has not enabled it. But some PHY drivers are
probably broken and offer pause when they should not.

Also, can you trigger the issue using UDP at say 75% the maximum
bandwidth. That should be low enough that the peer never even tries to
use pause.

All this pause stuff is just a stab in the dark. Something else to try
is to turn off various forms off acceleration, ethtook -K, and see if
that makes a difference.

     Andrew