How to force X11 resolution and refresh on Slackware 14.0
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How to force X11 resolution and refresh on Slackware 14.0
How can one force X11 to use a mode specified in xorg.conf but not detected ?
Since the introduction of KMS, things seem more difficult, for the end-user.
Here is what I have tried:
My xorg.conf is created by the xorgsetup program.
My display adapter is Radeon HD6550. System loads radeon framebuffer driver at boot which sets 1024x768@60 for all consoles.
X11 runs at same resolution and display.
EDID (/Xorg.0.log) reports several modes, up to 1024x768@60
The fact is that my system is connected to a 2 port KVM and I know for a fact that the setup works at 1024x768@75 because this is the other system's configuration (when in windows).
First problem: probably due to the KVM, but not sure, the video driver detects very few resolutions. I know the KVM is limiting here.
Second problem: following all known procedures to set up xorg.conf with a forced resolution, including all tips found on the net, so far I have failed.
Adding a new mode via xrandr and switching to it at runtime works.
Mode "1024x768_75" is generated by gtf
Mode "1024x768@75" is generated by PowerStrip on the other windows machine
Some web hints were to add
<------>Option "DPMS"
<------>Option "NoUseBIOS"
Some web hints were to add these to the Device section:
<------>Option "IgnoreEDID" "true"
<------>Option "NoDDC" "true"
<------>Option "Monitor-VGA-0" "Monitor0"
Some hints from the RADEON driver were to add these to the Device section:
<------>Option "EXAPixmaps" "off"
<------>Option "AccelDFS" "off"
Some hints were to add these to the Screen section:
<------>Option "UseEDID" "false"
<------>Option "UseEDIDDpi" "false"
And of course, this:
<------>SubSection "Display"
<------><------>Viewport 0 0
<------><------>Depth 24
<------><------>Modes<-><------>"1024x768@75"
<------>EndSubSection
None of these worked. X11 stubbornly starts only at 1024x768@60.
This is from the log:
[ 8681.234] (==) modeset(0): Default visual is TrueColor
[ 8681.234] (II) modeset(0): ShadowFB: preferred YES, enabled YES
[ 8681.238] (II) modeset(0): Output HDMI-0 using monitor section Monitor0
[ 8681.238] (**) modeset(0): Option "PreferredMode" "1024x768@75"
[ 8681.242] (II) modeset(0): Output DVI-0 has no monitor section
[ 8681.260] (II) modeset(0): Output VGA-0 using monitor section Monitor0
[ 8681.264] (II) modeset(0): EDID for output HDMI-0
[ 8681.268] (II) modeset(0): EDID for output DVI-0
[ 8681.285] (II) modeset(0): EDID for output VGA-0
[ 8681.285] (II) modeset(0): Printing probed modes for output VGA-0
[ 8681.285] (II) modeset(0): Modeline "1024x768@75"x75.0 78.75 1024 1048 1144 1312 768 769 772 800 +hsync +vsync (60.0 k
[ 8681.285] (II) modeset(0): Modeline "1024x768_75"x75.0 81.80 1024 1080 1192 1360 768 769 772 802 -hsync +vsync (60.1 k
[ 8681.285] (II) modeset(0): Modeline "1024x768"x60.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz
[ 8681.285] (II) modeset(0): Modeline "800x600"x60.3 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz e)
[ 8681.285] (II) modeset(0): Modeline "800x600"x56.2 36.00 800 824 896 1024 600 601 603 625 +hsync +vsync (35.2 kHz e)
[ 8681.285] (II) modeset(0): Modeline "848x480"x60.0 33.75 848 864 976 1088 480 486 494 517 +hsync +vsync (31.0 kHz e)
[ 8681.285] (II) modeset(0): Modeline "640x480"x59.9 25.18 640 656 752 800 480 489 492 525 -hsync -vsync (31.5 kHz e)
[ 8681.285] (II) modeset(0): Output HDMI-0 disconnected
[ 8681.285] (II) modeset(0): Output DVI-0 disconnected
[ 8681.285] (II) modeset(0): Output VGA-0 connected
[ 8681.285] (II) modeset(0): Using user preference for initial modes
[ 8681.285] (II) modeset(0): Output VGA-0 using initial mode 1024x768@75
[ 8681.285] (II) modeset(0): Using default gamma of (1.0, 1.0, 1.0) unless otherwise stated.
[ 8681.285] (==) modeset(0): DPI set to (96, 96)
=================================================================
However, in fact this still goes to 1024x768@60
and just a bit below:
[ 8681.286] (II) modeset(0): RandR 1.2 enabled, ignore the following RandR disabled message.
[ 8681.286] (==) modeset(0): DPMS enabled
[ 8681.286] (WW) modeset(0): Option "PreferredMode" is not used
I have 3 device sections.
One is with driver radeon
One is with driver modesetting
One is with driver vesa
Only if I add Option "Monitor-VGA-0" "Monitor0" to the card1 device (modesetting), then in the X11 log file I see Output VGA-0 using monitor section Monitor0, otherwise it says it has no monitor section.
I have tried combinations and combinations, I am probably missing something, but I can't make it start with 1024x768@75, I can only change with xrandr at runtime to that resolution.
For instance. "mv /etc/X11/xorg.conf /etc/X11/xorg.conf.save" then (re)start X and post you full X log (either use pastebin or as an attachment with the .txt extension)
Last edited by Didier Spaier; 10-30-2013 at 06:58 AM.
Reason: tyo corrected
Is that "VGA-1" ? (I'm only asking because the VGA output is named VGA-0 in the X11 logs).
Second, 1024x768@75 exists (at this time) only in xorg.conf but not in fb.modes.
There is a 1024x768-75 there, but mine was tweaked with timings identical from both systems connected to the KVM.
I will try to add 1024x768@75 with my timings to the kernel command line.
It worked, now the console is in 1024x768 75Hz.
Finally, I located this info in /usr/src/linux/Documentantion/fb/modedb.txt
Thank you for the help, I don't think I would've found it by myself.
From what I read there, the timings are either probed, or from a table (which is hardcoded).
When I try to set timings in the console with fbset, I get this:
I added the kernel command line as suggested, and my console is now 1024x768 75Hz (although not with the timings I would like). I can't set anything (except virtual resolution) with fbset.
I generated a new xorg.conf file (using xorgsetup) just to make sure I start clean.
I commented out the 2 driver sections about "vesa" and "modesetting" and the corresponding monitor and screen sections.
I customized my monitor0 section to use my modeline.
The problem is the same: monitor starts up in 1024x768 60Hz.
This is what xrandr reports:
Code:
xrandr
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 16384 x 16384
VGA-0 connected 1024x768+0+0 (normal left inverted right x axis y axis) 0mm x 0mm
1024x768@75 75.0 +
1024x768_75 75.0
1024x768 60.0*
800x600 60.3 56.2
848x480 60.0
640x480 59.9
HDMI-0 disconnected (normal left inverted right x axis y axis)
DVI-0 disconnected (normal left inverted right x axis y axis)
but, a later run of xrandr
~$ xrandr --output VGA-0 --mode 1024x768@75
will set the display to the mode I want and the refresh I want.
I still can't figure out what can I do in the config file xorg.conf so that X will start in the proper mode.
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