Hi,
Could I request a few kernel changes to improve out-of-the-box support on PowerPC please? They involve the ATI/radeon framebuffers and KMS support.
Since 11.04 the framebuffers used by Rage, Rage128 and radeon graphics cards have been compiled as modules. This has resulted in a number of problems, such as booting to a command prompt, loss of tty consoles and loss of suspend. Debian still builds in these modules and it has been commented by a few people who are testing 12.04 that Ubuntu and its derivatives are lagging behind in their user friendlyness.
Whilst it is possible to load the framebuffers as modules (and the Ubuntu PowerPC documentation describes how to do this), building back the modules into the kernel is the only way I can think of that will easily get everything working out of the box again. It will stop the openfirmware framebuffer from grabbing the resources.
The other change I would like to see is radeon defaulting to KMS on. This was the case in 10.04 and 10.10. This did cause a lot of complaints at the time about loss of 3d hardware acceleration, but 12.04 does not have UMS support anymore. KMS is the future! (if currently a little shakey! - there is no suspend with it and it crashes a lot with AGP)
Here is what I propose:
CONFIG_DRM_RADEON_KMS=y
CONFIG_FB_RADEON=y
CONFIG_FB_ATY128=y
CONFIG_FB_ATY=y
I don't know if there is some way to ensure that the above framebuffers are loaded in preference to the openfirmware framebuffer (CONFIG_FB_OF) ?
This setup should mean that tty consoles and suspend should work by default. Also, it will allow everything to be controlled from the kernel command line (yaboot prompt on PowerPC). If somebody wants fully working radeon KMS then they can disable radeonfb and offb with video=radeonfb:off video=offb:off. If there is some problem with KMS they can disable it with radeon.modeset=0. I've been over the options, and I think this is the best setup.
Finally, I've been trying to work out what to do with CONFIG_AGP_UNINORTH. Currrently it is compiled as a module, but debian has it built in. From the tests I've done there appears to be a race issue with it being compiled as a module. Under 10.04, KMS reverts to PCI mode because of it. This is actually a good thing as without forcing PCI mode (radeon.agmode=-1) it seems PowerPC radeon KMS crashes. From anecdotal evidence reading forums I would say Ubuntu nouveau support is better than Debain wheezy, and I'm wondering if this is the possible cause? So I'm thinking leave CONFIG_AGP_UNINORTH=m since we're trying to improve out-of-the box support. You can add uninorth_agp to /etc/modules to get it to load in time if needed. This gives a nice fancy splash screen, but results in the need for the additional radeon.agpmode=-1 parameter. Ideally, I need some nouveau people to test the stability of AGP (they use nouveau.agpmode=0 to disable AGP in 12.04).
Hopefully the above makes sense!
Thanks for reading this!
ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: linux-image-3.2.0-18-powerpc 3.2.0-18.28
ProcVersionSignature: Ubuntu 3.2.0-18.28-powerpc 3.2.9
Uname: Linux 3.2.0-18-powerpc ppc
AcpiTables:
AlsaVersion: Advanced Linux Sound Architecture Driver Version 1.0.24.
AplayDevices:
**** List of PLAYBACK Hardware Devices ****
card 0: Snapper [PowerMac Snapper], device 0: PMac Snapper [PowerMac Snapper]
Subdevices: 1/1
Subdevice #0: subdevice #0
ApportVersion: 1.94-0ubuntu1
Architecture: powerpc
ArecordDevices:
**** List of CAPTURE Hardware Devices ****
card 0: Snapper [PowerMac Snapper], device 0: PMac Snapper [PowerMac Snapper]
Subdevices: 1/1
Subdevice #0: subdevice #0
AudioDevicesInUse:
USER PID ACCESS COMMAND
/dev/snd/controlC0: adam 1147 F.... lxpanel
CRDA: Error: [Errno 2] No such file or directory
Card0.Amixer.info:
Card hw:0 'Snapper'/'PowerMac Snapper (Dev 38) Sub-frame 0'
Mixer name : 'PowerMac Snapper'
Components : ''
Controls : 15
Simple ctrls : 14
Date: Wed Mar 7 18:48:08 2012
HibernationDevice: RESUME=UUID=47641231-8c14-4d18-89b3-1d18df122ad5
InstallationMedia: Lubuntu 12.04 "Precise Pangolin" - Beta powerpc (20120301.1)
Lsusb:
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
PciMultimedia:
ProcEnviron:
LANGUAGE=en_GB:en
TERM=xterm
PATH=(custom, no user)
LANG=en_GB.UTF-8
SHELL=/bin/bash
ProcFB:
0 OFfb ATY,Via_A
1 OFfb ATY,Via_B
ProcKernelCmdLine: root=UUID=4c63bdc8-1be5-4b20-a938-298abd5ca619 ro quiet splash
RelatedPackageVersions:
linux-restricted-modules-3.2.0-18-powerpc N/A
linux-backports-modules-3.2.0-18-powerpc N/A
linux-firmware 1.71
RfKill:
0: phy0: Wireless LAN
Soft blocked: no
Hard blocked: no
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
I've been playing a bit more with this. I now think it is agpgart rather than uninorth_agp that influences whether KMS reverts to PCI mode or not. Well that is what it seems to be under 10.04. Agpgart is built into 12.04 already so I guess the nouveau people have been using AGP mode all along? It is hard to tell what affects what as the boot order can be quite random it seems and small things can have a 'butterfly' effect.
The parameter video=ofonly works well under 10.04 to disable the radeonfb framebuffer. This gives a very nice splash screen . However, I cannot replicate this under 12.04. The colours are all messed up (particularly on shutdown) and nothing I seem to do can correct this. As described in post 1, video=offb:off video=radeonfb:off gives the best splash results on boot, but has no effect on shutdown.