Dell 2405fpw and xorg.conf

[Markbnj]

Anyone know where I can get a good example of the Monitor and Screen section definitions for xorg.conf for the 2405fpw display? I'm having issues with x setting the refresh rate incorrectly when booting into 1920 x 1200 mode, and also resetting the res to 1600 x 1200. I looked at the conf file and the modes look like a mess. Not right for the monitor at all. I found some suggestions on the web, but there were various things that I wasn't sure of. Would feel better about it if someone here who has one has already configured it.

Anyway, any suggestions welcome.

 

[Nothinman]

Most monitors don't need any modelines these days since the driver can query the monitor's specs via DDC.

In screen section you should just have a handful of display subsections, one for each bit depth with a modes line containing whatever resolutions you want available like:

Modes "1680x1050" "1600x1200" "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480"

 

[Markbnj]

Thanks, Nothinman. It's the mode lines in the display subsection that look wrong. They contain resolutions like 1680 x 1680 that aren't possible on the monitor, and don't contain 1920 x 1200. Additionally I see nothing about refresh rates. When the system comes up the fonts look slightly distorted, and the display prefs report the vert. refresh at 96 hz., which isn't possible for this display. If I set it to 60 the fonts clear up. On the most recent reboot I couldnt' change the refresh rate. 96 was all that was offered.

I'll keep digging into it and look at DDC a little.

 

[Nothinman]

That's strange, I've never seen an LCD report anything but ~60hz.

Well nevermind, mine says 50hz right now.

 

[Markbnj]

I'm glad you mentioned that, because it's one of the things that was alarming me . I've seen the screen prefs applet report 50 hz. alone, 50hz with 51 hz. as an alternate, 50hz, 51hz., and 56hz, and once it displayed 99hz.

These were observed during a long session tonight at the end of which I'm happy to say the 2405 appears to be working correctly. I tried a number of routes, but kept getting funky signal timing sent to the panel. When it received signal it would display "Auto Adjust in Progress" for a few seconds, and I knew it was trying to compensate.

Let's see. I tried using the validated modes from xorg.0.log. I tried using the modelines produced by gtf. I tried using modelines I found on the web. I ran into a lot of discussion about this problem, which is apparently a confirmed issue with Ubuntu (not X) and wide-screen LCDs (maybe any widescreen). Eventually I found a blog by a guy with a 2405 who got his working in 1920 x 1200, and just copied that one modeline over to xorg.conf.

I also had trouble with the nvidia-settings applet. Several times after the screen came up borked I ran it and applied "auto" refresh timings and it cleared things up. But of course this wasn't sticky. I saved the settings to xorg.conf, but didn't realize that the settings applet wasn't running as root. It didn't complain, it just didn't write the file. I used gksudo to run it as root and saved the settings, and it did write the file... and screwed everything up. Had to revert to a backup.

Kind of an adventure, but it seems to be working now. I gave up on using nvidia-settings and just put a Gamma option in my Monitor section of xorg.conf. That was the only thing I wanted to change after res and refresh anyway,

 

[silverpig]

Just do a google search for a 1920x1200 modeline and paste it in. Then in the server layout only allow the 1920x1200 mode.

 

[Nothinman]

Just do a google search for a 1920x1200 modeline and paste it in.

That might work if you get lucky but most monitors are a little different so there's no telling whether it'll work or not.

Then in the server layout only allow the 1920x1200 mode.

Then nothing will be able to change resolution on the fly so games, VMWare full screen, etc won't work.

 

[Markbnj]

Just do a google search for a 1920x1200 modeline and paste it in. Then in the server layout only allow the 1920x1200 mode.

That's more or less what I did, but I ended up trying quite a few different suggested modelines (and means of obtaining modelines such as gtf) before I found one that would work reliably.

Then nothing will be able to change resolution on the fly so games, VMWare full screen, etc won't work.

Hmm, I hadn't thought of that. For the moment I don't think it's an issue, as I don't intend to run games or anything else that will want to change the res, but the VMWare fullscreen might be an issue at some point. Will need to find modelines for the other modes I want to support.

 

[Nothinman]

Will need to find modelines for the other modes I want to support.

Actually you might not, my laptop needs a modeline for 1680x1024 but not for any others.

 

[Markbnj]

Originally posted by: Nothinman

Will need to find modelines for the other modes I want to support.

Actually you might not, my laptop needs a modeline for 1680x1024 but not for any others.

So maybe I should just try adding the other modes I want to the screen section using the driver default names, and see what happens.

 

[xtknight]

To get modelines you can use the gtf (General Timing Formula) command:
usage: gtf x y refresh [-v|--verbose] [-f|--fbmode] [-x|--xorgmode]

I've always had luck just adding in "1680x1050" "1280x1024" etc to the regular one-liner...

Mine says 50 Hz too, but it's a bug. I know it's running at 60 Hz as it says 59.7 Hz in my monitor's OSD (on-screen display) and there is no difference in the motion as there would be if it was really at 50 Hz.

 

[Markbnj]

Yeah I figured the 50hz (and occasionally other numbers) were bugs since the nvidia settings app always reported the correct rate.

I did use gtf to set up the modes, but it didn't work correctly. I have no idea why, or where the blogger got the modeline I ultimately used. It's black magic .

Edit: Here's the monitor and screen sections that worked for me, in case anyone else needs it...

Section "Monitor"
Identifier "DELL 2405FPW"
Option "DPMS"
HorizSync 30-82
VertRefresh 60-60
Gamma 0.8
Modeline "1920x1200" 92.473920 1920 1992 2192 2464 1200 1209 1217 1251 -HSync +VSync interlace
EndSection

Section "Screen"
Identifier "Default Screen"
Device "NVIDIA Corporation NV34 [GeForce FX 5500]"
Monitor "DELL 2405FPW"
Defaultdepth 24
SubSection "Display"
Depth 24
Modes "1920x1200"
EndSubSection
EndSection

 

[SSP]

I had a similar problem where my refresh was set to 60 over the default 75 for the standard res. I just looked up the vert. and horiz. refresh rates from the monitor manual to add it to xorg.conf. The refresh shown on gnome is incorrect. I see it as 50 as well but the monitor report 75. Silly annoying bug.