Hi,
I'm seeing this when booting latest Linus tree + tip/master in kvm. Config is attached. Looks like it cannot find root fs and panics and calls the panic notifier which screams in drm_crtc.c because not all modeset locks are taken. Maybe bogus?
Anyway, just FYI:
... [ 25.406627] md: Autodetecting RAID arrays. [ 25.408078] md: Scanned 0 and added 0 devices. [ 25.409665] md: autorun ... [ 25.410916] md: ... autorun DONE. [ 25.412501] VFS: Cannot open root device "sda1" or unknown-block(0,0): error -6 [ 25.414524] Please append a correct "root=" boot option; here are the available partitions: [ 25.416719] 1f00 4096 mtdblock0 (driver?) [ 25.445497] 1f01 131072 mtdblock1 (driver?) [ 25.447975] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0) [ 25.449478] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.9.0-06610-g53332d7971f9 #1 [ 25.449478] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 25.449478] 0000000000008001 ffff88007c0f1db8 ffffffff825c3769 ffff88007c0f1e38 [ 25.449478] ffffffff825be42e 3130663182d86a47 6631002000000010 ffff88007c0f1e48 [ 25.449478] ffff88007c0f1de8 ffff88007c0f0031 ffff88007c0f1e60 0000000000000000 [ 25.449478] Call Trace: [ 25.449478] [<ffffffff825c3769>] dump_stack+0x27/0x30 [ 25.449478] [<ffffffff825be42e>] panic+0x10f/0x2a3 [ 25.449478] [<ffffffff8367fc72>] mount_block_root+0x2b5/0x3ad [ 25.449478] [<ffffffff8367fdd6>] mount_root+0x6c/0x77 [ 25.449478] [<ffffffff8367ffaf>] prepare_namespace+0x1ce/0x210 [ 25.449478] [<ffffffff8367f865>] kernel_init_freeable+0x2fd/0x31b [ 25.449478] [<ffffffff8367e948>] ? loglevel+0x46/0x46 [ 25.449478] [<ffffffff825a9ac0>] ? rest_init+0x1f0/0x1f0 [ 25.449478] [<ffffffff825a9ad6>] kernel_init+0x16/0x1a0 [ 25.449478] [<ffffffff825e611c>] ret_from_fork+0x7c/0xb0 [ 25.449478] [<ffffffff825a9ac0>] ? rest_init+0x1f0/0x1f0 [ 25.449478] drm_kms_helper: panic occurred, switching back to text console [ 25.449478] ------------[ cut here ]------------ [ 25.449478] WARNING: at drivers/gpu/drm/drm_crtc.c:82 drm_warn_on_modeset_not_all_locked+0x8d/0xc0() [ 25.449478] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 3.9.0-06610-g53332d7971f9 #1 [ 25.449478] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 25.449478] 0000000000000009 ffff88007c0f1c38 ffffffff825c3769 ffff88007c0f1c78 [ 25.449478] ffffffff81080303 0000000000000001 ffff880079dbef60 ffff88007ba7ab28 [ 25.449478] ffff88007ba7a290 0000000000000000 ffffffff831c3ad0 ffff88007c0f1c88 [ 25.449478] Call Trace: [ 25.449478] [<ffffffff825c3769>] dump_stack+0x27/0x30 [ 25.449478] [<ffffffff81080303>] warn_slowpath_common+0x93/0xd0 [ 25.449478] [<ffffffff8108046a>] warn_slowpath_null+0x2a/0x40 [ 25.449478] [<ffffffff816e841d>] drm_warn_on_modeset_not_all_locked+0x8d/0xc0 [ 25.449478] [<ffffffff816cb6a6>] drm_fb_helper_restore_fbdev_mode+0x26/0xa0 [ 25.449478] [<ffffffff816cb7b2>] drm_fb_helper_panic+0x92/0xf0 [ 25.449478] [<ffffffff810c875e>] notifier_call_chain+0x9e/0x250 [ 25.449478] [<ffffffff810c8b49>] __atomic_notifier_call_chain+0xa9/0x1c0 [ 25.449478] [<ffffffff810c8aa5>] ? __atomic_notifier_call_chain+0x5/0x1c0 [ 25.449478] [<ffffffff810c8c7e>] atomic_notifier_call_chain+0x1e/0x30 [ 25.449478] [<ffffffff825be46a>] panic+0x14b/0x2a3 [ 25.449478] [<ffffffff8367fc72>] mount_block_root+0x2b5/0x3ad [ 25.449478] [<ffffffff8367fdd6>] mount_root+0x6c/0x77 [ 25.449478] [<ffffffff8367ffaf>] prepare_namespace+0x1ce/0x210 [ 25.449478] [<ffffffff8367f865>] kernel_init_freeable+0x2fd/0x31b [ 25.449478] [<ffffffff8367e948>] ? loglevel+0x46/0x46 [ 25.449478] [<ffffffff825a9ac0>] ? rest_init+0x1f0/0x1f0 [ 25.449478] [<ffffffff825a9ad6>] kernel_init+0x16/0x1a0 [ 25.449478] [<ffffffff825e611c>] ret_from_fork+0x7c/0xb0 [ 25.449478] [<ffffffff825a9ac0>] ? rest_init+0x1f0/0x1f0 [ 25.449478] ---[ end trace be42dd504bbfe2a8 ]--- [ 25.449478] ------------[ cut here ]------------ [ 25.449478] WARNING: at drivers/gpu/drm/drm_crtc.c:84 drm_warn_on_modeset_not_all_locked+0xa8/0xc0() [ 25.449478] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 3.9.0-06610-g53332d7971f9 #1 [ 25.449478] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 [ 25.449478] 0000000000000009 ffff88007c0f1c38 ffffffff825c3769 ffff88007c0f1c78 [ 25.449478] ffffffff81080303 0000000000000001 ffff88007ba7ab20 ffff88007ba7ab28 [ 25.449478] ffff88007ba7a290 0000000000000000 ffffffff831c3ad0 ffff88007c0f1c88 [ 25.449478] Call Trace: [ 25.449478] [<ffffffff825c3769>] dump_stack+0x27/0x30 [ 25.449478] [<ffffffff81080303>] warn_slowpath_common+0x93/0xd0 [ 25.449478] [<ffffffff8108046a>] warn_slowpath_null+0x2a/0x40 [ 25.449478] [<ffffffff816e8438>] drm_warn_on_modeset_not_all_locked+0xa8/0xc0 [ 25.449478] [<ffffffff816cb6a6>] drm_fb_helper_restore_fbdev_mode+0x26/0xa0 [ 25.449478] [<ffffffff816cb7b2>] drm_fb_helper_panic+0x92/0xf0 [ 25.449478] [<ffffffff810c875e>] notifier_call_chain+0x9e/0x250 [ 25.449478] [<ffffffff810c8b49>] __atomic_notifier_call_chain+0xa9/0x1c0 [ 25.449478] [<ffffffff810c8aa5>] ? __atomic_notifier_call_chain+0x5/0x1c0 [ 25.449478] [<ffffffff810c8c7e>] atomic_notifier_call_chain+0x1e/0x30 [ 25.449478] [<ffffffff825be46a>] panic+0x14b/0x2a3 [ 25.449478] [<ffffffff8367fc72>] mount_block_root+0x2b5/0x3ad [ 25.449478] [<ffffffff8367fdd6>] mount_root+0x6c/0x77 [ 25.449478] [<ffffffff8367ffaf>] prepare_namespace+0x1ce/0x210 [ 25.449478] [<ffffffff8367f865>] kernel_init_freeable+0x2fd/0x31b [ 25.449478] [<ffffffff8367e948>] ? loglevel+0x46/0x46 [ 25.449478] [<ffffffff825a9ac0>] ? rest_init+0x1f0/0x1f0 [ 25.449478] [<ffffffff825a9ad6>] kernel_init+0x16/0x1a0 [ 25.449478] [<ffffffff825e611c>] ret_from_fork+0x7c/0xb0 [ 25.449478] [<ffffffff825a9ac0>] ? rest_init+0x1f0/0x1f0 [ 25.449478] ---[ end trace be42dd504bbfe2a9 ]--- [EOF]