Description of problem:
Undocking my ThinkPad X230 from the Docking Station which has a DELL 2709w connected via DisplayPort

Additional info:
WARNING: at drivers/gpu/drm/i915/intel_dp.c:2066 intel_dp_link_down+0x1b6/0x1f0 [i915]()
Hardware name: 23252DG
Modules linked in: fuse ip6table_filter ip6_tables ebtable_nat ebtables rfcomm bnep rc_dib0700_rc5 mt2060 iTCO_wdt iTCO_vendor_support snd_hda_codec_hdmi snd_hda_codec_realtek vfat fat usb_storage joydev dvb_usb_dib0700 dib8000 dib7000m dib0090 dib0070 dib7000p dib3000mc dibx000_common snd_usb_audio cdc_mbim dvb_usb uvcvideo videobuf2_vmalloc snd_usbmidi_lib dvb_core videobuf2_memops videobuf2_core snd_rawmidi videodev rc_core media btusb bluetooth cdc_ncm usbnet arc4 mii cdc_wdm cdc_acm acpi_cpufreq mperf coretemp crc32_pclmul iwldvm crc32c_intel mac80211 ghash_clmulni_intel microcode snd_hda_intel snd_hda_codec snd_hwdep snd_seq iwlwifi snd_seq_device i2c_i801 snd_pcm cfg80211 lpc_ich sdhci_pci mfd_core sdhci e1000e mmc_core ptp pps_core snd_page_alloc mei snd_timer thinkpad_acpi snd tpm_tis soundcore tpm rfkill tpm_bios wmi vhost_net tun macvtap macvlan kvm_intel kvm i915 i2c_algo_bit drm_kms_helper drm i2c_core video uinput
Pid: 747, comm: Xorg Not tainted 3.9.0-0.rc7.git3.2.fc20.x86_64 #1
Call Trace:
 [<ffffffff8105ca46>] warn_slowpath_common+0x66/0x80
 [<ffffffff8105cb1a>] warn_slowpath_null+0x1a/0x20
 [<ffffffffa00c38f6>] intel_dp_link_down+0x1b6/0x1f0 [i915]
 [<ffffffffa00c5af8>] intel_disable_dp+0x48/0x60 [i915]
 [<ffffffffa00b1049>] ironlake_crtc_disable+0x709/0x8c0 [i915]
 [<ffffffffa00b565f>] intel_crtc_update_dpms+0x6f/0xa0 [i915]
 [<ffffffffa00b572a>] intel_encoder_dpms+0x1a/0x30 [i915]
 [<ffffffffa00b8df8>] intel_connector_dpms+0x38/0x70 [i915]
 [<ffffffffa0039498>] drm_mode_obj_set_property_ioctl+0x308/0x320 [drm]
 [<ffffffffa00394e0>] drm_mode_connector_property_set_ioctl+0x30/0x40 [drm]
 [<ffffffffa00282c9>] drm_ioctl+0x4e9/0x5b0 [drm]
 [<ffffffffa00394b0>] ? drm_mode_obj_set_property_ioctl+0x320/0x320 [drm]
 [<ffffffff811aa9d5>] do_vfs_ioctl+0x305/0x520
 [<ffffffff81293d0e>] ? file_has_perm+0x8e/0xa0
 [<ffffffff8119a97e>] ? ____fput+0xe/0x10
 [<ffffffff811aac71>] sys_ioctl+0x81/0xa0
 [<ffffffff8164d6d9>] system_call_fastpath+0x16/0x1b

Potential duplicate: bug 903242