PPC64 - DRM - Radeon module causes Kernel Oops

[Hans J. Harff]

Dear List,

I am trying to get drm/dri to work on my box (see specs below), but
I am not having much success. DRM builds (both git and kernel-supplied
versions) and - apparently - loads just fine.
After 'modprobe radeon' the modules show up via lsmod and dmesg
provides encouraging messages:

[  722.854646] [drm] Initialized drm 1.1.0 20060810
[  722.871013] [drm] Initialized radeon 1.28.0 20060524 on minor 0

However, as soon as /dev/dri/card0 is being accessed (e.g. start X,
or simply do 'cat /dev/dri/card0') the console will display:

Bus error

and dmesg will provide the following:

*snip*

[  740.147714] Unable to handle kernel paging request for data at address 0xd000080080240040
[  740.147723] Faulting instruction address: 0xd00000000061448c
[  740.147731] Oops: Kernel access of bad area, sig: 7 [#1]
[  740.147735] SMP NR_CPUS=8 pSeries
[  740.147740] Modules linked in: radeon drm ipv6 genrtc usbhid ohci_hcd ehci_hcd usbcore
[  740.147828] NIP: d00000000061448c LR: d00000000061ba48 CTR: d00000000061ba00
[  740.147835] REGS: c0000002243d7730 TRAP: 0300   Not tainted  (2.6.24-gentoo-r3)
[  740.147839] MSR: 8000000000009032 <EE,ME,IR,DR>  CR: 44000428  XER: 00000010
[  740.147852] DAR: d000080080240040, DSISR: 0000000042000000
[  740.147858] TASK = c000000222f64030[5797] 'cat' THREAD: c0000002243d4000 CPU: 1
[  740.147863] GPR00: d000080080240040 c0000002243d79b0 d000000000640338 c00000021d3bc700 
[  740.147873] GPR04: 0000000000000001 c000000000e93660 0000000000000001 0000000000000000 
[  740.147882] GPR08: c000000000580340 c0000002216fd980 d000080080240000 0000000000000000 
[  740.147891] GPR12: 0000000024000484 c000000000580e80 0000000000000001 0000000000000000 
[  740.147900] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000010149f70 
[  740.147909] GPR20: fffffffffffffc00 0000000010016b58 c000000221c36780 d0000000005f2d70 
[  740.147918] GPR24: c00000021d3bc868 c00000021d3bc850 c000000221ba3280 c00000021d3bc700 
[  740.147928] GPR28: c00000021d3bc700 c00000021d3bc700 d00000000063f030 c00000021d3b5f00 
[  740.147940] NIP [d00000000061448c] .radeon_do_release+0x5c/0x1b0 [radeon]
[  740.147956] LR [d00000000061ba48] .radeon_driver_lastclose+0x48/0x90 [radeon]
[  740.147969] Call Trace:
[  740.147972] [c0000002243d79b0] [0000000000000001] 0x1 (unreliable)
[  740.147978] [c0000002243d7a40] [d00000000061ba48] .radeon_driver_lastclose+0x48/0x90 [radeon]
[  740.147992] [c0000002243d7ac0] [d0000000005d4c48] .drm_lastclose+0x78/0x510 [drm]
[  740.148016] [c0000002243d7b80] [d0000000005d6278] .drm_release+0x528/0x6f0 [drm]
[  740.148037] [c0000002243d7c50] [c0000000000c6eb8] .__fput+0xf8/0x230
[  740.148047] [c0000002243d7d00] [c0000000000c2dc0] .filp_close+0xa0/0x100
[  740.148054] [c0000002243d7d90] [c0000000000c4cfc] .sys_close+0xbc/0x170
[  740.148061] [c0000002243d7e30] [c0000000000086ac] syscall_exit+0x0/0x40
[  740.148069] Instruction dump:
[  740.148074] 2fbf0000 419e0160 e81f0056 2fa00000 409e011c e93f0110 2fa90000 419e002c 
[  740.148087] e9490018 39600000 380a0040 7c0004ac <7d60052c> 39200001 992d01dc 60000000 
[  740.148126] ---[ end trace d216a1ac5bfcac70 ]---


I have no idea how to tackle this problem, but if I can assist in
any way, I'd be more than happy to do so.

For what it's worth, I also have a Matrox G450 PCI that will work
just fine with drm/dri in this box.


Box: IBM OpenPower720
Arch: PPC64
Kernel: 2.6.24, also tried 2.6.25.2, 2.6.25.3
Distro: Gentoo, 64-bit UL
DRM: last tried with git pull 45 minutes ago
Card: Radeon 9200 PCI - Mac Edition, 128MB


Best Regards,

Hans.

.