Description of problem:
Everytime I boot my labtop connected to a dock station with a second screen (display port connected)

Additional info:
reporter:       libreport-2.2.3
WARNING: CPU: 1 PID: 1010 at drivers/gpu/drm/i915/intel_dp.c:3122 intel_dp_link_down+0x1a3/0x210 [i915]()
Modules linked in: ccm ip6t_rpfilter ip6t_REJECT xt_conntrack bnep btusb bluetooth ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev media arc4 iTCO_wdt iTCO_vendor_support dell_wmi sparse_keymap ppdev dell_laptop dcdbas x86_pkg_temp_thermal coretemp kvm_intel kvm iwlmvm crct10dif_pclmul mac80211 crc32_pclmul crc32c_intel snd_hda_codec_realtek snd_hda_codec_hdmi snd_hda_codec_generic ghash_clmulni_intel iwlwifi cfg80211 sdhci_pci snd_hda_intel
snd_hda_controller snd_hda_codec microcode snd_hwdep joydev snd_seq rfkill serio_raw snd_seq_device i2c_i801 snd_pcm lpc_ich mfd_core shpchp mei_me mei snd_timer snd soundcore wmi parport_pc parport i2c_hid dw_dmac dw_dmac_core i2c_designware_platform i2c_designware_core nfsd auth_rpcgss nfs_acl lockd sunrpc i915 e1000e i2c_algo_bit drm_kms_helper drm ptp i2c_core pps_core sdhci_acpi video sdhci mmc_core
CPU: 1 PID: 1010 Comm: X Not tainted 3.16.2-200.fc20.x86_64 #1
Hardware name: Dell Inc. Latitude E7240/05PTPV, BIOS A08 02/18/2014
0000000000000000 00000000e20871de ffff8802120df730 ffffffff81706ce1
0000000000000000 ffff8802120df768 ffffffff8108d0ad ffff880210a60000
ffff8800d9dc3000 0000000080000002 0000000000000002 ffff880210fef0d8
Call Trace:
[<ffffffff81706ce1>] dump_stack+0x45/0x56
[<ffffffff8108d0ad>] warn_slowpath_common+0x7d/0xa0
[<ffffffff8108d1da>] warn_slowpath_null+0x1a/0x20
[<ffffffffa017a683>] intel_dp_link_down+0x1a3/0x210 [i915]
[<ffffffffa017fad5>] intel_dp_complete_link_train+0x105/0x360 [i915]
[<ffffffffa0177c67>] intel_ddi_pre_enable+0x127/0x1a0 [i915]
[<ffffffffa015f98f>] haswell_crtc_enable+0x3af/0xa30 [i915]
[<ffffffffa0162332>] __intel_set_mode+0x812/0x1590 [i915]
[<ffffffffa00c5dc4>] ? drm_pick_crtcs+0x204/0x280 [drm_kms_helper]
[<ffffffffa0165756>] intel_set_mode+0x16/0x30 [i915]
[<ffffffffa016668d>] intel_crtc_set_config+0x8ed/0xdb0 [i915]
[<ffffffffa00716a1>] drm_mode_set_config_internal+0x61/0xe0 [drm]
[<ffffffffa00c4ca3>] restore_fbdev_mode+0xb3/0xe0 [drm_kms_helper]
[<ffffffffa00c4cf3>] drm_fb_helper_restore_fbdev_mode_unlocked+0x23/0x40 [drm_kms_helper]
[<ffffffffa00c6928>] drm_fb_helper_set_par+0x28/0x70 [drm_kms_helper]
[<ffffffffa00c68af>] drm_fb_helper_hotplug_event+0x8f/0xe0 [drm_kms_helper]
[<ffffffffa00c6940>] drm_fb_helper_set_par+0x40/0x70 [drm_kms_helper]
[<ffffffff813ce817>] fb_set_var+0x197/0x440
[<ffffffff810c5548>] ? __enqueue_entity+0x78/0x80
[<ffffffff810cb63b>] ? put_prev_entity+0x5b/0x3b0
[<ffffffff810c8379>] ? pick_next_entity+0xa9/0x190
[<ffffffff8101e9db>] ? __switch_to_xtra+0x16b/0x1a0
[<ffffffff81012929>] ? __switch_to+0x479/0x590
[<ffffffff813c4f11>] fbcon_blank+0x1f1/0x2f0
[<ffffffff81445bb8>] do_unblank_screen+0xb8/0x1f0
[<ffffffff8143cbce>] vt_ioctl+0x110e/0x1190
[<ffffffff814305b9>] tty_ioctl+0x289/0xb70
[<ffffffff812f1379>] ? avc_has_perm+0xd9/0x1a0
[<ffffffff81206820>] do_vfs_ioctl+0x2e0/0x4a0
[<ffffffff811f54fe>] ? ____fput+0xe/0x10
[<ffffffff81206a61>] SyS_ioctl+0x81/0xa0
[<ffffffff8170e329>] system_call_fastpath+0x16/0x1b