[PATCH 3/5] drm/dp/mst: change MST detection scheme

[Dave Airlie]

On 15 June 2016 at 13:49, Dave Airlie <airlied at gmail.com> wrote:
> Excuse me for top posting.
>
> So I finally got back to this patch, still don't like it.
>
> Apart from the doing 3 things in once which is just annoying, current
> userspace for tiled monitors
> relies on the behaviour that the cached edids are retrieved before the
> connector is show to userspace.
>
> This is so that for tiled monitors both connectors are shown with
> tiling properties so userspace can pick the correct monitor size.
>
> Now I realise this isn't great, since at least for the two cable 5K
> monitors you won't ever plug them in at once.
>
> So we should probably discuss more what userspace should do in the
> presence of a tiled monitor where it can only see one tile,
>
> If we go ahead with something like this, things will look kinda ugly
> as you plug in a 4k monitor and it'll try and set a mode
> on the first tile when it gets the hotplug (or it could be racing and
> notice the connectors before the hotplug). So it then
> sets the 1920x1080 mode on one connector and gets another hotplug to
> set the tiled mode up.

Though I think the fix is to leave the cached edid test in add port,

And maybe the rest of the patch is okay then.

Dave.