rotating display with nouveau

Skaperen · 06-29-2011, 03:50 PM

My NEC MultiSync EA241WM LCD monitor can be rotated 90 degrees, making the display effectively 1200 wide by 1920 high. However, it does not change the EDID data to describe this. The end result is the video comes up with the 90 degree rotation. BTW, this was done with everything completely powered down, just to be sure it wasn't just a case of a change that cannot be applied while up and running.

So, the next option seems to be to just force the 90 degree rotation in the video card and/or X server. I'm using the nouveau video driver with an NVIDIA chip and/or video card (depending on which computer at the moment), under (for now) Slackware64 13.37. Is there any configuration that can be used by this to do the rotation (counterclockwise since the monitor rotated clockwise) so I can have a 1200x1920?

MTK358 · 06-29-2011, 07:17 PM

First, see what the name of the monitor is, for example:

Code:

$ xrandr
Screen 0: minimum 320 x 200, current 2560 x 1024, maximum 8192 x 8192
DVI-0 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 376mm x 301mm
   1280x1024      60.0*+   75.0  
   1280x960       60.0  
   1152x864       75.0  
   1024x768       75.1     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        72.8     75.0     66.7     60.0  
   720x400        70.1  
DIN disconnected (normal left inverted right x axis y axis)
DVI-1 connected 1280x1024+1280+0 (normal left inverted right x axis y axis) 338mm x 270mm
   1280x1024      75.0 +   60.0* 
   1024x768       75.1     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        72.8     75.0     66.7     60.0  
   720x400

(Note that I have two monitors connected here)

Then, rotate the monitor (using the primary monitor from the above example):

Code:

xrandr --output DVI-0 --rotate right # you can also use "left"

Note that this won't stay after you restart X. If you start X using the startx command, then put the xrandr command in the "~/.xinitrc" scrpit. But if you don't, then I can't help.

Skaperen · 06-29-2011, 08:03 PM

Quote:

Originally Posted by MTK358

First, see what the name of the monitor is, for example:

Code:

$ xrandr
Screen 0: minimum 320 x 200, current 2560 x 1024, maximum 8192 x 8192
DVI-0 connected 1280x1024+0+0 (normal left inverted right x axis y axis) 376mm x 301mm
   1280x1024      60.0*+   75.0  
   1280x960       60.0  
   1152x864       75.0  
   1024x768       75.1     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        72.8     75.0     66.7     60.0  
   720x400        70.1  
DIN disconnected (normal left inverted right x axis y axis)
DVI-1 connected 1280x1024+1280+0 (normal left inverted right x axis y axis) 338mm x 270mm
   1280x1024      75.0 +   60.0* 
   1024x768       75.1     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        72.8     75.0     66.7     60.0  
   720x400

(Note that I have two monitors connected here)

Then, rotate the monitor (using the primary monitor from the above example):

Code:

xrandr --output DVI-0 --rotate right # you can also use "left"

Quote:

Originally Posted by MTK358

Thanks. I'll give this a try.

Note that this won't stay after you restart X. If you start X using the startx command, then put the xrandr command in the "~/.xinitrc" scrpit. But if you don't, then I can't help.

Maybe I can put it in the KDM config somewhere since I want it rotated at login prompt, too.

Skaperen · 06-29-2011, 08:41 PM

It didn't work. But the failure mode is that some logic in the display mechanism didn't get set up properly, and the display was all smeared at the pixel level. It looked like the display buffer geometry was changed from 1920x1200 to 1200x1920, but the pixel position transformations (e.g. rotation) are not taking place. Even though the pixels are smeared, I can see that things on the top of the screen are still on top, and things on the bottom are still on the bottom. Left and right can't easily be seen because all the smearing is in that direction. So either this NVIDIA chip (6150 SE ... a very low end) can't do it, or the driver can't do it ... and something was misreported as capable when it is not, leading to X thinking it was rotated.

Skaperen · 06-29-2011, 08:48 PM

If they were to do this right, and have the monitor detect the physical rotation had taken place, and change it's EDID geometry info accordingly, and do the pixel position transformations as part of the LCD scanout by swapping the X and Y grid sweeps, then it would just be a matter of changing the geometry, but not the scanout order, to accomplish this. If the EDID change was automatically detected, it should just work everywhere. And it would also work in text mode (xrandr doesn't do this, and if I rotate the monitor, I'd want text mode rotated, too).

JZL240I-U · 06-30-2011, 01:16 AM

Maybe you can find some hint for what you want in this thread:
http://www.linuxquestions.org/questi...712/page2.html

HTH.

Skaperen · 06-30-2011, 05:20 AM

Quote:

Originally Posted by JZL240I-U

Maybe you can find some hint for what you want in this thread:
http://www.linuxquestions.org/questi...712/page2.html

HTH.

Thanks. I'll try the other programs they mention. Hopefully it was just a "software failure to do it" issue than a "hardware cannot do it" issue. But this is a low end budget Nvidia chip, so it might not be able.

pupok · 06-30-2011, 01:29 PM

I have EIZO S2233W monitor, NVidia 6200 graphics card, OS slackware32 13.37, nouveau driver. No USB between PC and monitor.
AFAIK this monitor needs to be USB connected to a PC with _Windows_ utility installed, _Windows_ operating system is then instantly aware of rotating. I suppose EIZO needs this USB connection, through DVI it passes still the same EDID to OS. Don't know how NEC's dealing with rotating in it's FW.

Nevertheless, under slack I rotated the monitor 90 deg. - physically. Nothing happened to screen. Then rotated (manualy) SW-like with KRandrTray. This made it how it was supposed to. Made it while I was logged in a KDE user session.