Bug 63617

Make sure kms is enabled in your kernel and the radeon kernel module is loaded in kms mode before starting X.  xf86-video-ati 7.x releases only support kms.

On Wed, 17 Apr 2013, bugzilla-daemon@freedesktop.org wrote:

> 
> Comment # 1 on bug 63617 from Alex Deucher
> 
> Make sure kms is enabled in your kernel and the radeon kernel module is load
> ed
> in kms mode before starting X.  xf86-video-ati 7.x releases only support kms
> .
>
Where should I find the above?
So far, the only place I've found a reference to kms is in the Xorg.0.log:

[  3814.744] (II) [KMS] drm report modesetting isn't supported.

Perhaps I'm looking in all the wrong places.

Thank you for your help,
    Russ 
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Please attach the output of dmesg from after X failed to start.

Created attachment 78353 [details]
dmesg.txt

On Wed, 17 Apr 2013, bugzilla-daemon@freedesktop.org wrote:

> 
> Comment # 3 on bug 63617 from Michel Dänzer
> 
> Please attach the output of dmesg from after X failed to start.
> 
Attached.

This box boots to a command line. "startx," and after, did not add 
anything to dmesg.

I have a hunch: modesetting is done someplace else and the results
passed to the ati driver. The new ati driver requires modesetting to
work, and work properly. Here, modesetting hasn't worked right in years.
For example, with the vesa driver I get one mode that works; the rest
looks like giant backslashes.

Incidently, slackware-current went back to xorg-server-1.13.4
Tried it: still same problem.

   Russ

(In reply to comment #4)
> This box boots to a command line. "startx," and after, did not add 
> anything to dmesg.

There is no trace of the radeon kernel driver in the dmesg output. What happens if you run 'sudo modprobe radeon' before startx?

This is looking like a build / configuration issue rather than a bug. Have you tried asking for help on this in Slackware circles?

Invalid bug, reopen if you have issue with kms

On Wed, 24 Apr 2013, bugzilla-daemon@freedesktop.org wrote:

> Jerome Glisse changed bug 63617
> What
> Removed
> Added
> Status
> NEW
> RESOLVED
> Resolution
> ---
> INVALID

This is what I know:

1. xorg-server-1.2 & friends, uses ati-6 and works as expected.

2. xorg-server-1.13 & up, uses ati-7 and X does not start.

3. Changing xorg.conf for #2 above to use vesa driver:
   a) If Display has only one choice of 1024x768, 800x600, 640x480
      then X starts and runs at that mode.
   b) If Display has all 3, I can cycle cycle thru the 3 modes,
      but only one mode works. The other two look like backslashes.

4. I do not know if #2 & #3 above are related.

> 
> Comment # 6 on bug 63617 from Jerome Glisse
> 
> Invalid bug, reopen if you have issue with kms
>
Swell, but you didn't fix the problem.
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(In reply to comment #7)
> 1. xorg-server-1.2 & friends, uses ati-6 and works as expected.

6.x worked without KMS but 7.x no longer does. So for 7.x there is no way around making sure the radeon kernel driver is loaded (and with KMS enabled). Comment #5 provides some hints to get you started on that.

The man page for the ati driver says it's just a wrapper for the
real driver. So in /etc/X11/xorg.conf replaced "ati" with "radeon"

Same result:

StartX
The radeon driver loads in all its glory.
Then kms reports modesetting is not supported.
Based on that, somewhere ( Where? ) a decision is made to unload the
radeon driver.
Since /etc/X11/xorg.conf does not have a backup driver X exits.

I just eliminated ati-7 as the source of the problem.

YOu need to enable KMS, KMS is a kernel feature so nothing you do in userspace matter until you get kernel part right.

The dmesg you posted is with 3.2, it's a rather old kernel, also there is no mention to radeon kernel module so it seems your kernel build does not have either radeon or kms enabled.

You need to update to a newer kernel with kms enabled, it's the only way you can use the radeon driver with xserver 1.14

If you don't want to upgrade kernel then you can't use xserver 1.14 with anything else than vesa for this GPU (unless you write code yourself).