Comment 3 for bug 1855409

Thanks for the report @phausman! I've checked mainline and there's a commit that matches your report, we should try this one: 9adebac37e7d ("qede: Handle infinite driver spinning for Tx timestamp.") [0].

This is present in Eoan and Focal, but not in Bionic/Disco. After we confirm this is the fix we can proceed with the SRU - in case this patch doesn't help to alleviate the problem, then Eoan/Focal will be targeted too and we'll need to think in a proper solution.

Notice Xenial GA kernel (v4.4) does not have PTP support in qede driver, so this issue doesn't apply to Xenial (and once it's fixed in Bionic it'll reach organically Xenial-HWE kernel).

I'll work in building a 4.15 kernel for Bionic with the aforementioned fix, in order you can test.
Cheers,

Guilherme

[0] http://git.kernel.org/linus/9adebac37e7d