Radeon driver nolonger works on PowerPC without drm

Bug #1058753 reported by ojordan on 2012-09-29
This bug affects 1 person
Affects Status Importance Assigned to Milestone
xserver-xorg-video-ati (Ubuntu)

Bug Description

Hi, I'm trying to find out the best radeon setup for PowerPC in quantal and need some advice! The PowerPC kernel is currently setup with KMS enabled, BUT the legacy framebuffer radeonfb is still built in.

Although this is obviously not an ideal setup it seemed to work okay as a default setup up until August when UMS was dropped in quantal. I'll attach a log from my 12.04 install so you can see what used to happen. Despite the message "[KMS] drm report modesetting isn't supported" the radeon driver continues to load in 12.04 although drm/dri is non-functioning (because of the presence of radeonfb).

Now in quantal the radeon driver unloads pretty much immediatly after the "[KMS] drm report modesetting isn't supported" message. The fbdev driver takes over in 8 bit pseudo colour which causes all sorts of problems (bug 1046951).

Is it possible to have KMS without drm?

Radeon KMS on PowerPC still causes a lot of freezing problems and this is one of the reasons radeonfb is still included in 12.04. Radeonfb is also needed for suspend. Is there a way to have radeonfb and KMS working together (without drm) which seemed to be the case in 12.04?

If not then radeonfb should (IMHO) be removed from being built into the PowerPC kernel, but I currently would hit a new bug with that (bug 1058641).


ojordan (ojordan12345) wrote :

Under 12.04:

dmesg | grep drm
[ 38.849798] [drm] Initialized drm 1.1.0 20060810
[ 39.102286] [drm] radeon defaulting to kernel modesetting.
[ 39.102301] [drm] radeon kernel modesetting enabled.

ojordan (ojordan12345) wrote :
ojordan (ojordan12345) wrote :

Looking at the various logs that are spread out over the various bug reports I'm guessing that under 12.04 the radeon driver was using UMS despite it saying it was using KMS. Once somebody with expertise can confirm this then we can push to have the kernel config and PowerPC boot message updated as per bug 1040526 .

ojordan (ojordan12345) on 2012-09-29
description: updated
ojordan (ojordan12345) wrote :

In the 12.04 Xorg.0.log I have the line

[ 39.624] (II) RADEON(0): Color tiling enabled by default

If it was using KMS then it should be (*I think*) something like ths:

[ 98.582] (II) RADEON(0): KMS Color Tiling: disabled
[ 98.582] (II) RADEON(0): KMS Pageflipping: enabled

This is why I think 12.04 uses UMS even though the dmesg says KMS is enabled.

Bryce Harrington (bryce) on 2012-10-01
summary: - Radeon driver nolonger works without drm
+ Radeon driver nolonger works on PowerPC without drm
Changed in xserver-xorg-video-ati (Ubuntu):
importance: Undecided → Low
Maarten Lankhorst (mlankhorst) wrote :

Sorry, KMS is gone and we are unable to get Xorg server working in quantal without it.

Maarten Lankhorst (mlankhorst) wrote :


ojordan (ojordan12345) wrote :

Maarten, thanks for the comment, although I am not sure I follow it (!)

I know UMS has been dropped. I know it is never coming back. And I'm not suggesting for one minute that it should (the last version of radeon with UMS was largely broken from what I can gather).

I just need confirmation from an X expert that the current PowerPC kernel setup is unworkable. I can then get the kernel and/or boot message on the ISOs updated.

As I said in post 1 we are falling back into the fbdev driver in 8 bit pseudo colour. Is there a way to get this to a higher colour depth automatically? The current kernel config would be okay if we could start automatically in a higer colour depth. In the back of my mind I think I've read somewhere that framebuffers are set to 8 bit depth to save memory for KMS. Is this true?....

bugbot (bugbot) on 2012-10-04
tags: added: ppc
tags: added: precise
ojordan (ojordan12345) on 2012-10-04
tags: removed: precise
bugbot (bugbot) on 2012-10-11
tags: added: precise
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