[Intel-gfx] [RFC] drm/i915/dp: Remove i915.enable_dp_mst module parameter

[Ville Syrjälä]

On Thu, Oct 04, 2018 at 10:03:39AM +0300, Jani Nikula wrote:
> On Wed, 03 Oct 2018, Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com> wrote:
> > MST is enabled by default on all platforms that support it. I don't think
> > we should be providing a switch to work around MST issues as the feature
> > has been supported for a while now. Let's kill this module parameter
> > that we also do not test in CI.
> 
> I agree we don't want to provide this to users to *work around*
> issues. But maybe we want something like this to *debug* issues?

Yes. I was using it for that just a few days ago when looking at a bug.

Also the mst code lacks a bunch of features I think we'd want (remote dpcd,
remote i2c write, maybe others). It's still the unloved stepchild with no
one really focusing on improving it.

So I think it's way too early to think about removing this outright.
Not sure we should ever remove it really. What happens if in the future
most of our ci displays are mst capable? Do we just not test sst at all?
Granted a modparam is a probably a bit too coarse for that, but I think
we may want *something* to force sst.

-- 
Ville Syrjälä
Intel