Question about xrandr output name

[David Chen]

Hi,

Because of the naming change, it becomes difficult to create scripts to pe-configure display priority, resolution, position, and etc.
In my case, I have a device with Intel iGPU AMD dGPU, and I want to pre-configure display priority when more than one monitor are connected to the system.  In my own environment, I use xorg.conf and udev rules for hotplug detect, and it works because those names don’t change.  However, if I bring the device to work, configuration needs to be changed again for different monitors.  Further more, except for MST monitors causing name difference, I see different names when primary GPU is changed from one to another.  I don’t know if there are better solutions for this, to have designated output names for display interfaces.

Thanks and Regards,

David



> René Rebe <rene at exactcode.de> 於 2018年4月21日 上午12:09 寫道：
> 
> Hi,
> 
>> On 19 Apr 2018, at 09:22, David Chen <david0813 at gmail.com> wrote:
>> 
>> Hi,
>> 
>> I have observed that when connecting display port with MST enabled monitor, display output name in xrandr becomes something like DP-2-8, and there are more output interfaces listed in xrandr.  I am wondering how those names are defined.
> 
> As far as I have seen this are the logical connection going over the port.
> 
> However, I wanted to chime in for two questions I wanted to ask for some time already:
> 
> 1) i noticed the various open xorg drivers use different naming, could we unify this in regards to dashes and counting 0 and 1 based?
> E.g. DP-0 vs DP1 on intel vs. nouveau vs. modesetting vs. amdgpu, etc?
> 
> Of course not such a big deal, but it is a bit annoying to hardcode things based on machine types and such in my display setup shell script.
> 
> 2) I also have such an MST, Dell 4k display for some three years now. IIRC only the modesetting driver does setup the two MST halfs correctly, when using the -intel driver I have to manually xrandr --output … --left-of the two “virtual screens” to get an output that covers the whole display.
> Any thoughts on this? Any plans to generically improve this or in the intel driver?
> 
> Greetings,
>    René
> 
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