kernel messages: call trace

[galen]

getting loads of these at times,
always on bootup

Call Trace:
[<df2d00bc>] ? dump_stack+0x55/0x79
[<df05c16a>] ? __warn+0xea/0x110
[<f81ae2c1>] ? drm_wait_one_vblank+0x191/0x1a0 [drm]
[<f81ae2c1>] ? drm_wait_one_vblank+0x191/0x1a0 [drm]
[<df05c1d6>] ? warn_slowpath_fmt+0x46/0x60
[<f81ae2c1>] ? drm_wait_one_vblank+0x191/0x1a0 [drm]
[<df09b500>] ? wake_atomic_t_function+0x70/0x70
[<f8567718>] ? intel_get_load_detect_pipe+0x708/0x720 [i915]
[<df2d9130>] ? format_decode+0x3b0/0x440
[<f85a5ada>] ? intel_tv_detect+0x10a/0x690 [i915]
[<f825ee28>] ? drm_helper_probe_single_connector_modes+0x2e8/0x4d0 [drm_kms_helper]
[<f81b50bd>] ? get_properties+0xad/0x100 [drm]
[<f81b488c>] ? _object_find+0x5c/0xc0 [drm]
[<f81ba295>] ? drm_mode_getconnector+0x285/0x2f0 [drm]
[<df560477>] ? __ww_mutex_lock+0x17/0xa0
[<f81ba010>] ? drm_mode_getcrtc+0x140/0x140 [drm]
[<f81ac409>] ? drm_ioctl+0x149/0x4f0 [drm]
[<df0892fa>] ? sched_slice.isra.47+0x4a/0xb0
[<f81ba010>] ? drm_mode_getcrtc+0x140/0x140 [drm]
[<df083ee9>] ? scheduler_tick+0x69/0xd0
[<f81ac2c0>] ? drm_getclient+0x70/0x70 [drm]
[<df1d035c>] ? do_vfs_ioctl+0x8c/0x740
[<df0d01cb>] ? ktime_get+0x4b/0x110
[<df03bfab>] ? lapic_next_event+0x1b/0x20
[<df0d7a0d>] ? clockevents_program_event+0x9d/0x1a0
[<df1fd406>] ? __fsnotify_parent+0x96/0x100
[<df0d97b0>] ? tick_program_event+0x40/0x90
[<df0c9abb>] ? hrtimer_interrupt+0xbb/0x1a0
[<df1d0a70>] ? SyS_ioctl+0x60/0x70
[<df001b8d>] ? do_fast_syscall_32+0x8d/0x140
[<df56256a>] ? sysenter_past_esp+0x47/0x75
---[ end trace 3a1f2554e4782564 ]---
------------[ cut here ]------------

I've read that the "?" means the error is uncertain.

Are these errors of concern?