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

[Harry Wentland]

On 2017-01-25 05:46 PM, Alex Deucher wrote:
> On Wed, Jan 25, 2017 at 1:32 PM, Harry Wentland <harry.wentland at amd.com> wrote:
>> You mean rebase dal/dc on drm-next with these patches?
> 
> This is a core MST fix, so it would be good to get upstream for all drivers.
> 

Ignore my previous message. Somehow I though this was something else.

It didn't make it upstream because it broke tiled display. We'll need to
find some time to take a second look. It's definitely still on our list.

Harry


>>
>> 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.
> 
> I haven't had a chance to rebase that branch in quite a while.
> 
> Alex
> 
>>
>> 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
>>