Currently, it is possible to set scaling mode for a monitor only if the monitor is internal (LVDS, eDP). This is done through xrandr:
$ xrandr --prop
Screen 0: minimum 320 x 200, current 1680 x 1050, maximum 8192 x 8192
LVDS1 connected primary 1680x1050+0+0 (normal left inverted right x axis y axis) 331mm x 207mm
scaling mode: Full aspect
supported: None, Full, Center, Full aspect
$ xrandr --output LVDS1 --set "scaling mode" "Center"
However, it is not possible to do this for external panels (VGA, DVI, HDMI, DP). The "scaling mode" property is not exported for these panels. There are many use cases for it, mainly related to gaming. Also some medical software like electrocardiogram monitor can't be stretched.
The function is implemented on radeon drivers already.
(I simply copied the above description from bug: 80868)
Could somebody kind introduce the story why only LVDS and eDP have "scaling mode" property ?
From the driver, "scaling mode" will set pipe's PF_POS and PF_WIN, all pipes have this function, so I think all connectors maybe could have "scaling mode" property.
Historically, only the LVDS supported panel fitters. Flexible scalers that could be attach to any pipe were introduced with Ironlake, but nobody has written the code to apply them to anything other than LVDS/eDP (not even DSI!).
Could your team write the code to implement this ? One customer want to use this.
(In reply to XiongZhang from comment #3)
> hi, Chris:
> Could your team write the code to implement this ? One customer want to
> use this.
Feature requests like this need to come through proper internal channels.
Over a year later this is still unimplemented. This was proposed last year
but it died during review. Could it be reimplemented in any way that's acceptable upstream?
(In reply to Jani Nikula from comment #4)
> (In reply to XiongZhang from comment #3)
(In reply to Timo Aaltonen from comment #5)
> Over a year later this is still unimplemented. This was proposed last year
> but it died during review. Could it be reimplemented in any way that's
> acceptable upstream?
Hello Jani, Timo,
It's been a while since any update was made on this case. If this was followed up internally or discarded, could this bug be closed already?
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