re: port-amd64/49833: NetBSD-current (amd64/i386) reboot when start xinit on pc with HD6450

[matthew green <mrg%eterna.com.au@localhost>]

this seems to be specific to HD6450 (at least, it doesn't happen
on my hd5450, hd 4xxx, r300 systems.)  however, it does happen on
the new 6450 i have.

the problem seems to occur early in boot.  i patched
radeon_bo_create() to look for the misaligned base/offset and it
triggers before init starts:

radeon0: warning: created bo 0xfffffe80bec46810 with base ffff80000573f760 offset fffffe8046364c38
panic: kernel diagnostic assertion "(bo->tbo.mem.bus.base & (PAGE_SIZE - 1)) == 0" failed: file "/usr/src4/sys/external/bsd/drm2/dist/drm/radeon/radeon_object.c", line 205 bo bus base addr not page-aligned: ffff80000573f760
cpu1: Begin traceback...
vpanic() at netbsd:vpanic+0x13c
kern_assert() at netbsd:kern_assert+0x4f
radeon_bo_create() at netbsd:radeon_bo_create+0x23b
radeon_ttm_init() at netbsd:radeon_ttm_init+0x171
evergreen_init() at netbsd:evergreen_init+0xd9
radeon_device_init() at netbsd:radeon_device_init+0x4d0
radeon_driver_load_kms() at netbsd:radeon_driver_load_kms+0x6d
drm_dev_register() at netbsd:drm_dev_register+0x87
drm_pci_attach() at netbsd:drm_pci_attach+0x2d5
radeon_attach_real() at netbsd:radeon_attach_real+0x68
config_mountroot_thread() at netbsd:config_mountroot_thread+0x2c

the "warning" is also a new message i added, so i could track
what bo had what initial base/offset, and see where corruption
is introduced, but i did not expect it to occur so early.


more investigation required, but i wanted to share this info.


.mrg.