Comment 6 for bug 1830883

On Wed, Jun 05, 2019 at 07:36:50AM -0000, Emmanuel Grumbach wrote:
> Hi Seth,
>
> we debugged this and we found out that d0i3 was not disabled in iwlwifi.
> This is a kind of power saving thing that requires integration with the
> platform / kernel that should be enabled only for specific platform. Not
> something that should be enabled in a distribution kernel.
>
> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/net/wireless/intel/iwlwifi
> /iwl-drv.c?h=linux-5.1.y#n1670
>
> In mainline, it is disabled by default.
> Not sure what happened here.

It's also disabled by default in our kernels.

https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/disco/tree/drivers/net/wireless/intel/iwlwifi/iwl-drv.c#n1643

And the 5.1.5-050105-generic kernel which was tested and also has the
problem is an unmodified upstream build. My system has nothing specified
for the module parameter in /etc/modprobe.d, and I get Y from
/sys/module/iwlwifi/parameters/d0i3_disable.

@jnns, is it possible you've done something to your system to change the
module parameter? Could have been by adding it in in /etc/modprobe.d or
changing the kernel command line (cat /proc/cmdline). Not sure what else
might be changing it.