[Intel-gfx] [REGRESSION] Re: i915 driver crashes on T540p if docking station attached

[Linus Torvalds]

On Thu, Jul 30, 2015 at 8:57 AM, Takashi Iwai <tiwai at suse.de> wrote:
> On Thu, 30 Jul 2015 17:32:28 +0200,
> Theodore Ts'o wrote:
>>
>> BTW, is there any chance that I can suspend my laptop, and then move
>> it from my docking station at home (where I have a Dell 30" display)
>> to my docking station at work (where I have a Dell 24" display), and
>> actually have the new monitor be detected?  For at least the past
>> year, I have to reboot in order to be able to use the external
>> monitor?  This used to work, but it's been a very long-standing
>> regression.  I undrstand that Multi-stream DP is a evil horrible hack,
>> and supporting it is painful, but this used to work, and it hasn't in
>> a long time.  :-(
>
> Relevant with this?
>    https://bugs.freedesktop.org/show_bug.cgi?id=89589
>
> I wanted to check this by myself, too, as the same bug was reported to
> openSUSE bugzilla, but I had no hardware showing it.

Hmm. That commit e7d6f7d70829 looks like it should still revert fairly
cleanly (just move the call to intel_dp_mst_resume() to before the
intel_modeset_setup_hw_state() call and locking).

Ted, worth checking out, even if that presumably ends up
re-introducing some WARN_ON's..

                    Linus