Radeon RS690 and gcc 4.8.0

[NEIL.IBEY at forces.gc.ca]

Good Day,

Since switching to gcc 4.8.0 to compile the kernel (versions ranging
from 3.6.11 through 3.9-rc8), I've been getting the following kernel
oops at radeon/radeon_vram_location.  This is on an HP 6715b laptop
using an R300 RS690 chip.  No issues with the newer radeon chipsets and
no issues if gcc 4.7.2 is used.  I wonder, gcc bug or gcc exposing a
radeon bug?
Neil 

[drm] Initialized drm 1.1.0 20060810
[drm] radeon kernel modesetting enabled.
[drm] initializing kernel modesetting (RS690 0x1002:0x791F
0x103C:0x30C2).
[drm] register mmio base: 0xD0200000
[drm] register mmio size: 65536
ATOM BIOS: ATI
BUG: unable to handle kernel paging request at 00008043
IP: [<f8ed53e4>] radeon_vram_location+0x14/0x1f0 [radeon]
*pdpt = 0000000036205001 *pde = 0000000000000000 
Oops: 0002 [#1] SMP 
Modules linked in: radeon(+) cfbfillrect cfbimgblt cfbcopyarea
i2c_algo_bit drm_kms_helper ttm drm fbcon bitblit softcursor fb fbdev
font ipv6 hid_generic usbhid hid fuse powernow_k8 joydev ohci_hcd
ehci_pci ehci_hcd tg3 ptp pcmcia pps_core libphy fan processor ac button
container battery video thermal thermal_sys yenta_socket pcmcia_rsrc
shpchp pcmcia_core hp_wmi sparse_keymap snd_hda_codec_analog rfkill wmi
snd_hda_intel snd_hda_codec snd_hwdep psmouse serio_raw evdev ati_agp
agpgart snd_pcm i2c_dev i2c_piix4 i2c_core snd_page_alloc snd_timer snd
soundcore k8temp hwmon
Pid: 1681, comm: modprobe Not tainted 3.8.6-smp #1 Hewlett-Packard HP
Compaq 6715b (GZ268US#ABA)/30C2
EIP: 0060:[<f8ed53e4>] EFLAGS: 00010296 CPU: 0
EIP is at radeon_vram_location+0x14/0x1f0 [radeon]
EAX: 00000000 EBX: 00007fff ECX: 78000000 EDX: 00007fff
ESI: 00000000 EDI: c0000000 EBP: f608bc8c ESP: f608bc3c
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
CR0: 8005003b CR2: 00008043 CR3: 36298000 CR4: 000007f0
DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
DR6: ffff0ff0 DR7: 00000400
Process modprobe (pid: 1681, ti=f608a000 task=f6a1ecb0 task.ti=f608a000)
Stack:
 f63f1b40 00005000 00000000 00000000 00007fff f68a4000 c0000000 f608bc8c
 f8f0fa21 f608bc7c f68a4000 f608bc7e f608bc8c f8eda7b8 f608bc84 00000000
 b54c0101 00007fff f68a4000 c0000000 f608bcb8 f8f10981 78000000 00000000
Call Trace:
 [<f8f0fa21>] ? rs690_pm_info+0x31/0x400 [radeon]
 [<f8eda7b8>] ? radeon_atombios_sideport_present+0x38/0xa0 [radeon]
 [<f8f10981>] rs690_init+0x191/0x2f0 [radeon]
 [<f8ed63a2>] radeon_device_init+0x602/0x6d0 [radeon]
 [<f8ed4ec0>] ? cail_mc_write+0x20/0x20 [radeon]
 [<f8ed7b8c>] radeon_driver_load_kms+0x7c/0x130 [radeon]
 [<f8d40bd3>] drm_get_pci_dev+0x133/0x250 [drm]
 [<f8ebe1c1>] radeon_pci_probe+0xc1/0xf0 [radeon]
 [<c11bff97>] pci_device_probe+0x57/0x90
 [<c12247d6>] really_probe+0x46/0x1c0
 [<c11bfb36>] ? pci_match_device+0x96/0xa0
 [<c1224a07>] __driver_attach+0x77/0x80
 [<c1224990>] ? __device_attach+0x40/0x40
 [<c1223027>] bus_for_each_dev+0x47/0x80
 [<c1224429>] driver_attach+0x19/0x20
 [<c1224990>] ? __device_attach+0x40/0x40
 [<c1223fe7>] bus_add_driver+0xa7/0x250
 [<c11bfef0>] ? pci_dev_put+0x20/0x20
 [<c11bfef0>] ? pci_dev_put+0x20/0x20
 [<c1224f95>] driver_register+0x65/0x130
 [<c11bfe4d>] __pci_register_driver+0x2d/0x30
 [<f8d40de5>] drm_pci_init+0xf5/0x100 [drm]
 [<f8f87000>] ? 0xf8f86fff
 [<f8f870d4>] radeon_init+0xd4/0xd6 [radeon]
 [<c10011f2>] do_one_initcall+0x102/0x150
 [<c10acdbe>] ? __vunmap+0x6e/0xd0
 [<c1071fed>] load_module+0x165d/0x1da0
 [<c1072798>] sys_init_module+0x68/0x90
 [<c1381a98>] syscall_call+0x7/0xb
Code: e8 d2 cb 34 c8 89 f8 e9 e2 fe ff ff 8d 74 26 00 8d bc 27 00 00 00
00 55 89 e5 57 56 53 83 ec 44 8b 75 0c 89 45 d8 a1 38 52 f7 f8 <89> 72
44 89 c3 89 c1 c1 fb 1f 0f a4 c3 14 8b 42 18 89 5d e8 8b
EIP: [<f8ed53e4>] radeon_vram_location+0x14/0x1f0 [radeon] SS:ESP
0068:f608bc3c
CR2: 0000000000008043
---[ end trace 7a5a89da8e33c170 ]---