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

[Harry Wentland]

You mean rebase dal/dc on drm-next with these patches?

I'll see if I find some time today or tomorrow to do that. We'll
probably need that anyways for our atomic rework.

Do you still rebase amd-staging on drm-next?
https://cgit.freedesktop.org/~agd5f/linux/log/?h=amd-staging-drm-next
looks a few weeks old now.

Harry

On 2017-01-25 12:24 PM, Alex Deucher wrote:
> On Wed, Jan 25, 2017 at 12:16 PM, Krzysztof Nowicki
> <krzysztof.a.nowicki at gmail.com> wrote:
>> Hi,
>>
>> On środa, 15 czerwca 2016 14:14:01 CET  wrote:
>>> 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.
>> Is this patch still being considered for pulling in?
>>
>> Recently I've been fighting with a HP UltraSlim docking station with a MST hub
>> inside in order to get it working with the amdgpu DAL/DC code. I couldn't get
>> it to work until I stumbled upon this patch. Applying it solved the issue
>> instantly.
>>
>> What I have found during debugging is that the MST hub would return SST sink
>> port numbers < 8 which resulted in no EDID being retrieved and in turn the
>> status of the outputs was 'disconnected'.
> Harry,
>
> Any chance you could re-spin this against something more recent and re-send?
>
> Alex