randr: Virtual monitor not present with MST display

[Wentland, Harry]

On 2019-03-08 4:11 a.m., Michel Dänzer wrote:
> On 2019-03-06 5:35 p.m., Paul Menzel wrote:
>> On 03/06/19 15:55, Michel Dänzer wrote:
>>> On 2019-03-06 1:41 p.m., Paul Menzel wrote:
>>>> On 03/05/19 20:07, Alex Deucher wrote:
>>>>> On Tue, Mar 5, 2019 at 1:16 PM Paul Menzel wrote:
>>>>
>>>>>> Using the MST display Dell UP3214Q (two panels) with an AMD system,
>>>>>> the virtual monitor object is not created. GDM and Xfce consider both
>>>>>> panels as separate screens (`xrandr --listmonitors`).
>>>>>>
>>>>>> [...]
>>>>
>>>> I didn’t provide the output of xrandr in my previous message.
>>>>
>>>>     $ xrandr --listmonitors
>>>>      Monitors: 2
>>>>      0: +DisplayPort-9 1920/698x2160/392+0+0  DisplayPort-9
>>>>      1: +DisplayPort-10 1920/698x2160/392+1920+0  DisplayPort-10
>>>>
>>>> Please find the X.Org X Server log attached.
>>>>
>>>>>> With an Intel system, the monitor object is shown.
>>>>
>>>> To clarify, the modesetting driver is used with the Intel hardware.
>>>
>>> Does this work better with the modesetting driver on the AMD system?
>>
>> With Linux 4.19.19, there was the same problem with the modesetting driver
>> during my limited testing.
>>
>> Updating to Linux 4.20.13, it worked with the modesetting driver, but the
>> AMDGPU driver still failed to properly utilize the MST monitor.
> 
> Does
> https://gitlab.freedesktop.org/xorg/driver/xf86-video-amdgpu/merge_requests/32
> help?
> 

Michel, do you know if this is supposed to work with xf86-video-amdgpu? When I've tried it before I didn't have any luck but didn't have time to look into it.

Harry

>