[PATCH v2 00/12][SRU][OEM-5.14]Fix i915 TypeC disconnect problems for Intel ADL-P

[Chris Chiu]

On Fri, Nov 26, 2021 at 3:55 PM Andrea Righi <andrea.righi at canonical.com> wrote:
>
> On Thu, Nov 25, 2021 at 06:10:13PM +0800, Chris Chiu wrote:
> > BugLink: https://bugs.launchpad.net/bugs/1952041
> >
> > [Impact]
> > When the ADL-P system connects the external display via TypeC port, it will hang after unplugging the TypeC connector. The system will never come back until reboot.
> >
> > [Fix]
> > Intel has released a patch set to fix the TypeC PHY connect/disconnect logic. The shift for ownership of PHY and power domain will be handled correctly for ADL-P.
> >
> > [Test]
> > The ADL-P system will no longer freeze and the ownership will shift correctly after disconnecting the external display connects via TypeC port.
> >
> > [Where problem could occur]
> > It's kind of a big refactor for the i915 TypeC PHY handling logic. Don't know if there's any problems on older platforms. Targeting only on Jammy/Unstable and latest OEM kernel for lower risk.
> >
> > v2: remove SRU for U since #4 of this series should be cleanly cherry-picked to U and J.
>
> I was considering to apply this also to jammy:linux, but "big refactor"
> is a little worrying in terms of maintainability of the i915 code, that
> always gets problematic due to the inevitable custom patches that we
> usually apply...
>
> Do you think there's any chance that we get this via the regular updates
> from stable? Maybe if it wasn't not done already we should try to ask to
> apply this to stable.
>
> Thanks,
> -Andrea

The patch set is in 5.15.0-rc4 now so the regular update would also get
these patches applied.  My major concern is these patches are too new
for older platforms (ex. TGL) which we haven't yet time for verification and
I don't want to incur huge impact on older kernels for this.