On Thu, 2012-05-24 at 10:18 +0400, Dmitry Eremin-Solenikov wrote:

Hello, colleagues,

I'm trying to enable an AGP slot (again) on my Maple board (dual 
PPC970FX board, with CPC925 (U3H) north bridge).

  For now I'm stuck with a problem: I use radeon card, drm-radeon driver 
with KMS.

If I force drm-radeon to think about a card as about PCI card (by 
commenting corresponding lines in drm_radeon_kms.c), everything works, I 
get framebuffer, working X11, etc. If I enable agpgart-uninorth driver
and RADEON_IS_AGP flag in drm driver, I get an Oops early during the 
bootstrap. Relevant part of the log (I can send full dmesg of normal 
bootstrap or this oops on request, if that would help).

Machine Check probably means that there's a HW configuration issue,
possibly something missing in the initialization of the AGP hardware to
make it actually work.

Cheers,
Ben.

[    2.820647] Linux agpgart interface v0.103
[    2.824909] agpgart-uninorth 0000:f0:0b.0: Apple U3H chipset
[    2.830668] agpgart-uninorth 0000:f0:0b.0: Found device u3, rev 35
[    2.843611] agpgart-uninorth 0000:f0:0b.0: configuring for size idx: 64
[    2.850638] agpgart-uninorth 0000:f0:0b.0: AGP aperture is 256M @ 0x0
[    2.857646] [drm] Initialized drm 1.1.0 20060810
[    2.862567] [drm] radeon defaulting to kernel modesetting.
[    2.868091] [drm] radeon kernel modesetting enabled.
[    2.873222] radeon 0000:f0:10.0: enabling device (0000 -> 0003)
[    2.880311] radeon 0000:f0:10.0: enabling bus mastering
[    2.885591] [drm] initializing kernel modesetting (RV350 
0x1002:0x4152 0x18BC:0x0416).
[    2.893629] [drm] register mmio base: 0xD0020000
[    2.898260] [drm] register mmio size: 65536
[    2.947112] [drm] GPU not posted. posting now...
[    3.051033] agpgart-uninorth 0000:f0:0b.0: putting AGP V3 device into 
8x mode
[    3.058197] radeon 0000:f0:10.0: putting AGP V3 device into 8x mode
[    3.064666] radeon 0000:f0:10.0: GTT: 256M 0x00000000 - 0x0FFFFFFF
[    3.070864] [drm] Generation 2 PCI interface, using max accessible memory
[    3.077672] radeon 0000:f0:10.0: VRAM: 128M 0x00000000C0000000 - 
0x00000000C7FFFFFF (128M used)
[    3.086487] [drm] Supports vblank timestamp caching Rev 1 (10.10.2010).
[    3.093126] [drm] Driver supports precise vblank timestamp query.
[    3.099291] [drm] radeon: irq initialized.
[    3.103404] [drm] Detected VRAM RAM=128M, BAR=128M
[    3.108214] [drm] RAM width 128bits DDR
[    3.112263] [TTM] Zone  kernel: Available graphics memory: 496682 kiB
[    3.118732] [TTM] Initializing pool allocator
[    3.123346] [drm] radeon: 128M of VRAM memory ready
[    3.128256] [drm] radeon: 256M of GTT memory ready.
[    3.133295] [drm] radeon: ib pool ready.
[    3.137708] [drm] radeon: 1 quad pipes, 1 Z pipes initialized.
[    3.144018] radeon 0000:f0:10.0: WB disabled
[    3.148326] [drm] fence driver on ring 0 use gpu addr 0x00000000 and 
cpu addr 0xd000000000066000
[    3.157474] [drm] Loading R300 Microcode
[    3.162480] [drm] radeon: ring at 0x0000000000001000
[    3.167569] [drm] ring test succeeded in 0 usecs
cpu 0x0: Vector: 200 (Machine Check) at [c000000000d63aa0]
     pc: c0000000000cc07c: .trace_hardirqs_on_caller+0x6c/0x190
     lr: c0000000000152f4: .cpu_idle+0x1a4/0x220
     sp: c000000000d63d20
    msr: 9000000000009032
   current = 0xc000000000c4db30
   paca    = 0xc00000000ffff000   softe: 0        irq_happened: 0x01
     pid   = 0, comm = swapper/0
enter ? for help
[c000000000d63db0] c0000000000152f4 .cpu_idle+0x1a4/0x220
[c000000000d63e50] c000000000008fb8 .rest_init+0xe8/0x110
[c000000000d63ee0] c000000000ba2998 .start_kernel+0x3e4/0x408
[c000000000d63f90] c000000000007558 .start_here_common+0x20/0x48
0:mon> x
[  843.783295] Oops: Machine check, sig: 7 [#1]
[  843.787589] SMP NR_CPUS=4 Maple
[  843.790768] Modules linked in:
[  843.793855] NIP: c0000000000cc07c LR: c0000000000152f4 CTR: 
c000000000023eac
[  843.800920] REGS: c000000000d63aa0 TRAP: 0200   Not tainted  (3.4.0+)
[  843.807376] MSR: 9000000000009032 <SF,HV,EE,ME,IR,DR,RI>  CR: 
24222222  XER: 00000006
[  843.815412] SOFTE: 0
[  843.817607] TASK = c000000000c4db30[0] 'swapper/0' THREAD: 
c000000000d60000 CPU: 0
[  843.825035] GPR00: 0000000000000000 c000000000d63d20 c000000000d63280 
c0000000000152f4
[  843.833169] GPR04: 0000000000000000 c000000000099d10 0000000000000001 
0000000000000002
[  843.841302] GPR08: 0100000000000000 c000000000e828e8 0140000000000000 
0000000000000000
[  843.849436] GPR12: 0000000044222282 c00000000ffff000 0000000000000000 
0000000000000000
[  843.857570] GPR16: 0000000000ff8750 0000000000cdc890 00000000010001e0 
0000000000000000
[  843.865702] GPR20: 0000000000000000 0000000000000000 000000001dcd6500 
0000000000000000
[  843.873835] GPR24: 0000000000000000 0000000000ec7b00 9000000000009032 
c000000000d7b178
[  843.881979] GPR28: c000000000d7b278 0000000000000008 c000000000c970f8 
c0000000000152f4
[  843.890314] NIP [c0000000000cc07c] .trace_hardirqs_on_caller+0x6c/0x190
[  843.896942] LR [c0000000000152f4] .cpu_idle+0x1a4/0x220
[  843.902181] Call Trace:
[  843.904640] [c000000000d63d20] [c000000000d63db0] 
init_thread_union+0x3db0/0x4000 (unreliable)
[  843.913317] [c000000000d63db0] [c0000000000152f4] .cpu_idle+0x1a4/0x220
[  843.919964] [c000000000d63e50] [c000000000008fb8] .rest_init+0xe8/0x110
[  843.926615] [c000000000d63ee0] [c000000000ba2998] 
.start_kernel+0x3e4/0x408
[  843.933611] [c000000000d63f90] [c000000000007558] 
.start_here_common+0x20/0x48
[  843.940866] Instruction dump:
[  843.943868] 40de00a4 e92d01c8 800908e8 2f800000 40de0094 e93e8098 
80090000 2f800000
[  843.951829] 409e0030 880d01f2 2fa00000 40de00b0 <e93e84e8> 88090000 
2f800000 40de00c8


Looking for any suggestions on this.