Help adding mode to XRANR

[NickMalvern]

Hi
I've singularly failed to get xrandr to add modes that do exist on a couple of laptops (they work in windows). The problems relate to an old Mitac laptop, but now I have hit the same problem on a old Sony Vaio, the monitor settings does not offer the correct mode available in windows - in this case 1280x800.
I have tried it when booted from a Peppermin6 LiveCD. Despite all the 'complaints' the mode gets offered in the monitor settings - but has no effect. The Mitac was tried from an installed PM6 system, with very similar problems. I obtained the modeline using 'cvt'.

I get various objections to the code lines, the important bits are listed below.

Any help would be very much appreciated. It might just be something simple I have failed to type in the right format!
In particular, I am a touch concerned that "Screen 0" is right - I can't find an example of that.
Many thanks

Terminal lines:

peppermint@peppermint ~ $ xrandr xrandr: Failed to get size of gamma for output default Screen 0: minimum 640 x 480, current 1024 x 768, maximum 1024 x 768 default connected 1024x768+0+0 0mm x 0mm 1024x768 61.0* 800x600 61.0 640x480 60.0

peppermint@peppermint ~ $ xrandr --newmode 1280x800_60.00 83.50 1280 1352 1480 1680 800 803 809 831 -hsync +vsync xrandr: Failed to get size of gamma for output default X Error of failed request: BadName (named color or font does not exist) Major opcode of failed request: 140 (RANDR) Minor opcode of failed request: 16 (RRCreateMode) Serial number of failed request: 19 Current serial number in output stream: 19

peppermint@peppermint ~ $ xrandr --addmode screen 0 1280x800_60.00 xrandr: unrecognized option '1280x800_60.00' Try 'xrandr --help' for more information.

peppermint@peppermint ~ $ xrandr xrandr: Failed to get size of gamma for output default Screen 0: minimum 640 x 480, current 1024 x 768, maximum 1024 x 768 default connected 1024x768+0+0 0mm x 0mm 1024x768 61.0* 800x600 61.0 640x480 60.0 1280x800_60.00 (0x185) 83.5MHz h: width 1280 start 1352 end 1480 total 1680 skew 0 clock 49.7KHz v: height 800 start 803 end 809 total 831 clock 59.8Hz

[chithanh]

The addmode and newmode option only work for xrandr 1.2 capable drivers.
Your driver does obviously not support xrandr 1.2 as it still says "default" instead of an xrandr 1.2 output name.

If you cannot use an xrandr 1.2 capable graphics driver, configure the modeline via the xorg.conf Monitor section.

[NickMalvern]

The addmode and newmode option only work for xrandr 1.2 capable drivers.
Your driver does obviously not support xrandr 1.2 as it still says "default" instead of an xrandr 1.2 output name.

If you cannot use an xrandr 1.2 capable graphics driver, configure the modeline via the xorg.conf Monitor section.

Thanks you for responding quickly, at least that clarifies why I am getting nowhere!
I guess that will be a permanent problem with these 2 laptops as the drivers are almost certainly 'old' too - and will not have updates.

Can you point possibly me to some clear instructions about how to add things to xorg.conf ?
I had a first stab at that but failed to even find that file (I believe it may no longer be used in he latest Ubuntu distros???)

I am quite desperate to get this sorted - so any help is exceedingly appreciated!

[chithanh]

First thing to find out is whether there is an xrandr 1.2 driver for your graphics chip.
If yes, use that.
If not, you need to create xorg.conf (X -configure can do that for you) and add to the Monitor section a ModeLine entry.

[NickMalvern]

First thing to find out is whether there is an xrandr 1.2 driver for your graphics chip.
If yes, use that.
If not, you need to create xorg.conf (X -configure can do that for you) and add to the Monitor section a ModeLine entry.

How do I do that?
I can't find a list of supported drivers.
My machines have:
1. VGA compatible SIS 650 graphics
2. Nvidia GeForce 8400M GT

A bit more help appreciated!
I sort of doubt I'll find better drivers - especially for the first one - so guidance on xorg.cof would really help too.
Thanks very much indeed.

[NickMalvern]

I found what claims to be a compiled ready-to-use driver for SiS here:

http://zatherz.cba.pl/sis/

Installed it, but so far it has made no difference. Do I need to 'select it' somehow, or still proceed with xorg.conf as well ?

[chithanh]

Simply installing the driver is often not enough, and if it is not intended for your distribution / X server version this can royally mess up your system. Stay with your distro provided packages unless you have specific reason not to, and know what you are doing.

The drivers supporting the SiS 650 are xf86-video-sis and xf86-video-xgi, neither of which is xrandr 1.2 capable. With your generated config from the command I mentioned above you can add the ModeLine to the Monitor section (you can copy cvt output verbatim into the correct place). Also you can switch between sis and xgi drivers in the Device section.

EDIT: It appears that the drivers already support built-in preconfigured modes as per http://www.winischhofer.net/linuxsispart1.shtml#24 which is probably worth a try first.

The xf86-video-nouveau driver supports xrandr 1.2 fine.

[NickMalvern]

Thank you so much for your help.

With a bit of additional help (as 'sudo X -configure' says the server is already running) I have managed to create an xorg.conf file - added the requisite monitor modeline - and having copied it to /etc/X11 - bingo - it works!

That done, I have to say that I have failed to fully understand your answers.

1. What am I meant to glean from the Ref at 'Edit'? (I can't see why/if it applies to my Sis650)

2. How could I use 'xf86-video-nouveau driver' ? - it is NOT offered by the 'additional drivers' as a possible proprietary driver (although I have used a Nouveau driver that way on another laptop).

3. "Also you can switch between sis and xgi drivers in the Device section" - I'd be grateful for some clarification, I don't understand the significance or purpose of this. sorry!

I do remain most grateful - no-one else explained why I could not use XRANR to solve the problem.

[chithanh]

My edit mentions that the driver supports built-in modes which can be added by listing them in the "Screen" section's "Modes" line. So you didn't need to use cvt. But if it works now, leave it as it is now.
Switching drivers in the "Device" section is done by editing the "Driver" line. Because there are two drivers (sis and xgi) which are compatible with your hardware, one may work better than the other.

1. VGA compatible SIS 650 graphics

For this graphics chip there are no xrandr 1.2 capable drivers. So you have to use the classic xorg.conf way of adding modes.

2. Nvidia GeForce 8400M GT

For this graphics chip you can use the nouveau driver which supports xrandr 1.2.