[ltp] Changing CRT frequency

[Alex Deucher]

On 2/27/06, Shem Multinymous <multinymous@gmail.com> wrote:
> Hi,
>
> On 2/27/06, Alex Deucher <alexdeucher@gmail.com> wrote:
> > > > > > (e.g., 1024x768-1024x768-60 1024x768-1024x768-85, etc.)
> > Sorry about that, I was speaking off the top of my head.  I just meant
> > to yse custom modelines in your metamodes.  Use modeline names without
> > the reserved characters  (they are just strings, you can call a mode
> > 'crazymode' if you like) or if you want clone modes with different
> > resolutions, etc. use '+' instead of '-' in your metamodes.
>
> Ah, got it. Actually "+" is also reserved, but with "_" it works
> nicely -- almost.

If you use + instead of - in your metamodes it treats it as a clone
mode.  That's what I was trying to say (ie, 1024x768-800x600 vs.
1024x768+800x600).  you can use it to mix in mixed clone modes along
with a dualhead configuration.

> I defined MetaModes like this:
>
> Section "Monitor"
>         ...
>         Modeline "CRT_1400x1050_85" 179.26  1400 1504 1656 1912  1050 105=
1
> 1054 1103 -hsync +vsync  # 1400x1050 179.3 MHz, 93.8 kHz, 85.0 Hz
>         Modeline "CRT_1400x1050_75" 155.80  1400 1464 1784 1912  1050 105=
2
> 1064 1090 +hsync +vsync  # 1400x1050 155.8 MHz, 81.5 kHz, 74.8 Hz
>         ...
> EndSection
>
> Section "Device"
>         ...
>         Option      "MetaModes" "1400x1050-CRT_1400x1050_85
> 1400x1050-CRT_1400x1050_75 "
>         ...
> EndSection
>
> This works, and the Xorg log shows that two metamodes are created, but
> RANDR only shows one mode (the first one). Perhaps that's because the
> radeon driver reports both modes to have resolution 1400x1050 and
> refresh rate 0Hz. So I still can't switch between the modes on the
> fly.

Make sure you list both those custom modes in the screen section of
your config. Also if it's throwing out modes based on having the same
refresh, then you may need a newer version of the radeon driver (I
plugged in dummy refresh rates at some point to allow this). FWIW,
this used to work when I committed this code, but I haven't tested it
in ages.

Alex

>
>   Shem
>