Manual and options for the "modesetting" driver

Stefan Monnier monnier at
Thu Jun 18 19:12:46 PDT 2015

>> I'm trying to use the "modesetting" driver for a dual-monitor setup
>> using a displaylink adapter and a Poulsbo card, and where the monitors
>> are rotated and where I only want 16bpp.
>> The only part I managed to get is an output on my Poulsbo-connected
>> monitor, but all the other things I specified in my xorg.conf seem to be
>> ignored, so: is there a manual somewhere listing the available options
>> (I've discovered "kmsdev" so far)?
> Now things goes with xrandr command , type xrandr , see what Xorg.bin
> detects . 

That's part of the problem:
- "xrandr --listproviders" shows two cards, confirmaing that the
  displaylink is found.
- yet "xrandr" only shows one screen and one monitor (which is the
  monitor connected to the Poulsbo card).
- How do I run "xrandr" to rotate the GDM login screen?

> You just want set xorg.conf, to force some detection or drives at
> startup (in xorg.conf you also could do some settings), after that
> dual-monitor setup will be managed with xrandr and other ui tools of
> xrandr.

Yes, I know that flow as well, but it currently doesn't work since
I don't see the second screen in "xrandr".  And even if/when I can make
that work it's not very satisfactory since the orientation of the
monitors is the same for all users of the machine, so it should be
configured once and for all in the system files.

And of course, in any case, I'm pretty sure that the "modesetting"
driver accepts options, so there's gotta be some place where these are

        Stefan "who wishes the driver used another name, like kmsdev or
                something, because with the current name, web-searches are
                impossible because of the number of false positives"

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