xrandr panning for small laptop screen

[olenb]

Hello,

I can't get panning (virtual screen space) to work on fedora 16, so I can get more veritcal rows than 768.

xrandr -q
Screen 0: minimum 320 x 200, current 1366 x 768, maximum 8192 x 8192
LVDS1 connected 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
   1366x768       60.0*+   40.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
VGA1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
DP1 disconnected (normal left inverted right x axis y axis)

I use xrandr to setup panning using this command

xrandr --output LVDS1 --rate 60 --mode 1366x768 --fb 1366x1024 --panning 1366x1024

but it doesn't work correct. When the mouse moves to the bottom of the screen the display only pans a tiny
amount, not to the full change of size. I've verified that by using 1366 for the vertical size as well.

The results seem to take effect, when I query for the size of the display:

xrandr -q
Screen 0: minimum 320 x 200, current 1366 x 1024, maximum 8192 x 8192
LVDS1 connected 1366x1024+0+0 (normal left inverted right x axis y axis) 344mm x 193mm panning 1366x1024+0+0
   1366x768       60.0*+   40.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9

Is there anything else that need to change, some gnome setting that doesn't seem to be showing up on the system configuration panels? Should I submit a bug report?

[PabloTwo]

I don't know for sure, but maybe it's due to Fedora blacklisting most/all of the fb (framebuffer) drivers. Have a look in /etc/modprobe.d/blacklist.conf. Might depend on which video driver you're using. I'm working in F12 at the moment, but I think I see pretty much the same thing in my F16 install.

[olenb]

could be. xrandr panning doesn't work with XFCE environment either. I commented out all the blacklisted fram buffer lines, but
still no luck. Anyone else have a suggestion?

[duende]

This is a known bug, see
https://bugs.freedesktop.org/show_bug.cgi?id=39949
and
http://forums.fedoraforum.org/showthread.php?t=264200

[MattMayfield]

Not sure if you figured this out already, but after many hours I finally found out how to make xrandr scaling & panning work on my Linux netbook, so to save others searching for this solution, I'm replying to as many of these threads as possible. I found one easy workaround, and a more involved fix.

**The workaround - as seen here: http://askubuntu.com/questions/11348...lay-resolution

Set up a "dummy" VGA device, that won't actually be physically connected, at the effective resolution you want. Here's what I did to make my 1024x600 Dell 10v netbook have a "virtual" 1280x720 screen. (Plus, since the pixels aren't square, this corrects the aspect ratio too.)

xrandr --newmode "1280x720" 60.00 1280 1320 1376 1650 720 722 728 750
xrandr --addmode VGA1 1280x720
xrandr --output VGA1 --mode 1280x720 --output LVDS1 --fb 1280x720 --scale 1.25x1.2

Presto. Of course, you'll have to do some math (to determine final virtual resolution vs. scaling factors) to adjust to your specific situation.

**A permanent solution -

I haven't gotten this to work, as I'm still fairly new to Linux and it involves downloading the source for xorg-server, patching one of the files that determines screen boundaries, and compiling/installing. Here is the patch I found, by Chris Bagwell, to be applied to rrcrtc.c:

https://bugs.freedesktop.org/attachment.cgi?id=59557

Hope that helps.

Matt

[duende]

Matt, thanks for this info. I appreciate that you registered just to tell us about it. I have solved my problem with panning by patching and recompiling xorg, as described in that bug report mentioned above (I still use the solution for older version of xorg because I compiled it a while ago and then blocked updates to xorg).
But the solution with dummy VGA device seems interesting.
I guess the example you provided is for scaling. What command do you use for panning?

---------- Post added at 08:24 AM ---------- Previous post was at 12:45 AM ----------

OK, the question about panning was rather silly. It works.

Matt, I found that your solution works for me. Thanks, it is much easier than recompiling xorg.
My only question is how do you figure out the numbers in

xrandr --newmode "1280x720" 60.00 1280 1320 1376 1650 720 722 728 750

I understand 60.00, 1280, 720, but how about the rest? I realized though, that it seems to be OK to put zero in the remaining ones (although probably not optimal).

I guess that to make changes more permanent one could try to define the new mode in xorg.conf.