Radeon Driver Default Display Resolution

Alex Deucher alexdeucher at gmail.com
Mon Mar 24 07:12:33 PDT 2008


On Mon, Mar 24, 2008 at 8:54 AM, Greg Treantos <gtreanto at gmail.com> wrote:
> Thanks Alex adding the modelines worked. I tried Beso's suggestion first
> without success. I have 2 follow up questions,
>
> 1) What changed in 7.3 that caused this issue?

The radeon driver got xrandr 1.2 support.  Previous versions of the
driver assumed one monitor per driver instance while with xrandr you
may have several monitors.  With xrandr it is much more important to
get mode information about each monitor since you may have two or more
monitors connected with vastly different capabilities.  The previous
version of the driver more or less always assumed a monitor was
connected and forced whatever mode you specified.  You can still do
this, but as you see, the configuration has changed a bit.  This page
should give you a good overview:
http://www.intellinuxgraphics.org/dualhead.html

> 2) How do I generate Mode lines so I can update 1280x1024 and 1024x768 at a
> higher frequency than the 60hz currently posted in xrandr?

use cvt:
$ cvt 1280 1024 85
# 1280x1024 84.84 Hz (CVT 1.31M4) hsync: 91.46 kHz; pclk: 159.50 MHz
Modeline "1280x1024_85.00"  159.50  1280 1376 1512 1744  1024 1027
1034 1078 -hsync +vsync

Alex

>
> Thanks again for your help..
>
> Just for completeness Beso's suggestion
>
> i don't see anything that seems like a monitor props scan. i neither don't
> see things that seem odd in your xorg.conf. i'd only suggest you to add the
> following to it:
>
> > Section "Modes"
> >   Identifier   "Modes[0]"
> > EndSection
>
> >
> > Section "Extensions"
> >   Option        "DAMAGE" "true"
> >   Option        "RENDER" "true"
> >   Option        "Composite" "Enable"
> > EndSection
> >
>
> the following to the screen section:
>
>   Device       "** ATI Radeon (generic)               [radeon]"
>    Monitor    "IBM P70"
>
> the first options should set up a mode section, the extensions would enable
> damage, rendering and compositing (this would increase your overall xorg
> experience), while the addons in the screen section should tell xorg that
> that screen has the defaults for the monitor ibm p70 and of the device
> indicated above. so it should set the resolution to the first available in
> the 16bit section of the screen section (since your screen is set to 16bit
> by default).
>  --
>
>
>
> On Sun, Mar 23, 2008 at 10:46 AM, Alex Deucher <alexdeucher at gmail.com>
> wrote:
>
> >
> > On Sun, Mar 23, 2008 at 7:55 AM, Greg Treantos <gtreanto at gmail.com> wrote:
> > > I am running a Gentoo system and after upgrading to x11 7.3 now when I
> issue
> > > startx, xwindows starts with a screen resolution of 1152x768 54.8hz.
> Before
> > > I upgraded the system would start with whatever I had in the display
> section
> > > of xorg.conf. Once the system is up I can use xrandr to switch to my
> > > preferred 1400x1050 @ 74.8hz.  In xorg.conf I don't have 1152x768 set
> and I
> > > have tried commenting out HorizSync, VertRefresh, adding  Option "NoDDC"
> > > "True", Option "UseEDID" "False",  and HorizSync and source: edid (x
> would
> > > not start with option) without success. My question is how does xwindows
> > > pick this resolution, how can I force x to use the resolutions in the
> > > Display Subsection or startx with 1400x1050.. Thanks
> > >
> >
> >
> > (II) RADEON(0): Found color CRT connected to primary DAC
> >
> > The driver is not able to get an edid from the monitor so it doesn't
> > know what modes the monitor supports.  At this point the server
> > attempts to (rather poorly) pick a mode within the sync ranges of your
> > monitor as specified in your monitor section.  Ajax has attempted to
> > fix up the mode selection logic in these cases in newer X servers.
> > For now you have to specify a preferred mode and possibly some
> > modelines, depending on the referesh rate you want.  See below.
> >
> > Alex
> >
> >
> > > xorg.conf
> > >
> > > Section "InputDevice"
> > >
> > >      Identifier   "Mouse1"
> > >      Driver   "mouse"
> > >      Option "Protocol"    "Auto"   # Auto detect
> > >      Option "Device"      "/dev/input/mice"
> > >      Option "ZAxisMapping"   "4 5 6 7"
> > >
> > >  EndSection
> > >
> > >  Section "Monitor"
> > >
> > >      Identifier  "IBM P70"
> > >      HorizSync   29-82
> > >      VertRefresh 50-120
> >
> > Modeline "1400x1050_75.00"  156.00  1400 1504 1648 1896  1050 1053
> > 1057 1099 -hsync +vsync
> > Modeline "1400x1050_74.80"  155.50  1400 1504 1648 1896  1050 1053
> > 1057 1099 -hsync +vsync
> > Option "PreferredMode" "1400x1050_74.80"
> >
> >
> >
> >
> > >
> > >  EndSection
> > >
> > >  Section "Device"
> > >      Identifier  "** ATI Radeon (generic)               [radeon]"
> > >      Driver      "radeon"
> > >  EndSection
> > >
> > >  Section "Screen"
> > >      Identifier  "Screen 1"
> > >      Device      "** ATI Radeon (generic)               [radeon]"
> > >      Monitor     "IBM P70"
> > >      DefaultDepth 16
> > >
> > >      Subsection "Display"
> > >          Depth       8
> > >          Modes       "1400x1050" "1280x1024" "1024x768"
> > >          ViewPort    0 0
> > >          Virtual     1600 1280
> > >      EndSubsection
> > >      Subsection "Display"
> > >          Depth       16
> > >          Modes       "1400x1050" "1280x1024" "1024x768"
> > >          ViewPort    0 0
> > >          Virtual     1600 1280
> > >      EndSubsection
> > >      Subsection "Display"
> > >          Depth       24
> > >          Modes       "1400x1050" "1280x1024" "1024x768"
> > >          ViewPort    0 0
> > >          Virtual     1600 1280
> > >      EndSubsection
> > >  EndSection
> > >
> > >  Section "ServerLayout"
> > >      Identifier  "Simple Layout"
> > >      Screen "Screen 1"
> > >      InputDevice "Mouse1" "CorePointer"
> > >      InputDevice "Keyboard1" "CoreKeyboard"
> > >
> > >  EndSection
> > >
> > >  Section "DRI"
> > >      Mode 0666
> > >  EndSection
> > >
> >
>
>
>
> --
> Greg



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