Configuring xrandr: too small screen size?

[Alex Deucher]

On Sun, May 23, 2010 at 12:18 PM, Dotan Cohen <dotancohen at gmail.com> wrote:
> On 23 May 2010 19:07, Alex Deucher <alexdeucher at gmail.com> wrote:
>> The ums (userspace modesetting) radeon driver cannot resize the front
>> buffer after X has started.  You need to either pre-allocate a larger
>> front buffer using a Virtual directive in your xorg.conf, or enable
>> kms (kernel modesetting).  The kms-enabled radeon driver supports
>> buffer resizing.
>>
>
> Thanks, Alex. The kms-enabled radeon driver is only available in the
> ~.34 kernels, no?

It's actually been available for several kernel releases, but didn't
come out of staging until 2.6.33.  However some distros have
backported the 2.6.33 drm bits to 2.6.32. so your distro kernel may be
ok.

>
> Assuming that I were to pre-allocate a larger front buffer using a
> Virtual directive in xorg.conf, how would I do that? Would this be
> enough?:
>   Section "Screen"
>       Identifier       "Default Screen"
>       Monitor          "Generic Monitor"
>       DefaultDepth     24
>
>       SubSection "Display"
>           Depth                24
>           Modes                "1680x1050" "3360x1050" "1680x2100"
>           Virtual              3360 2100
>       EndSubSection
>   EndSection
>
> The newer *buntus don't even have an xorg.conf file, and there are
> some difficulties in getting it to read on that hte user puts in
> there. I am basing my question on the content of this page:
> http://www.thinkwiki.org/wiki/Xorg_RandR_1.2

Yeah, that's what you want.  See this page as well:
http://wiki.debian.org/XStrikeForce/HowToRandR12

Alex

>
> Thanks.
>
> --
> Dotan Cohen
>
> http://gibberish.co.il
> http://what-is-what.com
>