randr: Virtual monitor not present with MST display

[Michel Dänzer]

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?


-- 
Earthling Michel Dänzer               |              https://www.amd.com
Libre software enthusiast             |             Mesa and X developer