Origin of display connector numbers in XServer (e.g. HDMI1, HDMI2, DP1)
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Andreas N
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Published on 2014-08-21T21:23:27Z
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2014/08/21
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a custom mainboard has a DVI and a DisplayPort connector on the board. Currently, everything that is connected at DVI will be named "HDMI2" in XServer. I can see that by calling the "xrandr" tool (in Ubuntu Trusty Tahr). A display connected to the DP connector will be named "DP1" or "HDMI1", if I use a DP-to-DVI adapter.
We are now testing a slightly upgraded board version, which has a newer CPU (Intel J1800, Baytrail) among other things and the position of the DVI and DP connectors are switched. Also, everything at the DVI port is called "HDMI1" and something connected to the DP port gets "DP2" or "HDMI2".
Q: What causes these numbers to be produced in this manner and where (probably in the kernel) is it happening?
I suspect the cause to be hardware related. Specifically, at which CPU pins the connector pins are routed and attached to.
Q: Would it be possible to influence this numbering scheme in order to retain the previous numbering behaviour?
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