Description of problem:
I do not really know what I did to trigger this. I did some swtching between gnome login screen, VT (ctrl+alt+f3) and logging into system trying to use gnome in wayland. It went approximately like this:

After boot I tried to log in using gnome with wayland. gnome-shell crashed (it is possibly #1200439). I switched to "ctrl+alt+f3" terminal to log in as root an look at journal. I did that, then I ran „journalctl -af>file“ and tried logging in to gnome with wayland again (another gnome crash) so I again changed to vt, stopped journalctl, looked through file, logged out (I think), switched to login screen, changed session to gnome and tried to logging in. Instead of desktop I got black display. Closing lid (it is a laptop), pressing power button, trying ctrl+alt+f<number> or ctrl+alt+del did not help, so I restarted computer (long press of power button)

Additional info:
reporter:       libreport-2.3.0
kernel BUG at drivers/gpu/drm/drm_crtc.c:536!
invalid opcode: 0000 [#1] SMP 
Modules linked in: fuse xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack tun bridge stp llc bnep vfat fat uvcvideo videobuf2_vmalloc videobuf2_core videobuf2_memops v4l2_common arc4 videodev intel_rapl iosf_mbi ppdev media iwlmvm x86_pkg_temp_thermal coretemp kvm_intel snd_hda_codec_idt mac80211 snd_hda_codec_generic snd_hda_codec_hdmi hp_wmi sparse_keymap iTCO_wdt iTCO_vendor_support snd_hda_intel snd_hda_controller snd_hda_codec snd_hwdep kvm iwlwifi snd_seq snd_seq_device joydev snd_pcm btusb tpm_infineon rtsx_pci_ms bluetooth cfg80211 snd_timer memstick serio_raw snd parport_pc hp_accel lis3lv02d mei_me tpm_tis input_polldev i2c_i801 parport hp_wireless wmi soundcore rfkill tpm
 shpchp mei lpc_ich nfsd auth_rpcgss nfs_acl lockd grace binfmt_misc sunrpc dm_crypt radeon i915 crct10dif_pclmul crc32_pclmul crc32c_intel rtsx_pci_sdmmc mmc_core ttm i2c_algo_bit drm_kms_helper e1000e drm ghash_clmulni_intel rtsx_pci ptp mfd_core pps_core video
CPU: 0 PID: 1157 Comm: JS GC Helper Not tainted 3.19.3-200.fc21.x86_64 #1
Hardware name: Hewlett-Packard HP ZBook 14/198F, BIOS L71 Ver. 01.21 09/03/2014
task: ffff88003f91a6c0 ti: ffff88022a154000 task.ti: ffff88022a154000
RIP: 0010:[<ffffffffa005f439>]  [<ffffffffa005f439>] drm_framebuffer_free_bug+0x9/0x10 [drm]
RSP: 0018:ffff88022a157b18  EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8800a91abc00 RCX: 0000000000000000
RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffff8802215706c8
RBP: ffff88022a157b18 R08: ffff8802273d1a70 R09: 0000000000000000
R10: ffff880221643500 R11: ffff880236242200 R12: ffff8802215706c0
R13: ffff880242164e00 R14: ffff8800a9156378 R15: ffff8800a9156088
FS:  00007f09c2ffd700(0000) GS:ffff88024ea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fea62706d48 CR3: 0000000001c11000 CR4: 00000000001407f0
Stack:
 ffff88022a157b38 ffffffffa006132d ffff8800a91abc00 ffff8800a9156000
 ffff88022a157b78 ffffffffa016fe01 ffff8800a91560d0 ffff880242164e00
 ffff8800a9156000 ffff880236243cd0 ffff880236243cc8 ffff8800a9156088
Call Trace:
 [<ffffffffa006132d>] drm_plane_force_disable+0x9d/0xd0 [drm]
 [<ffffffffa016fe01>] restore_fbdev_mode+0x51/0xf0 [drm_kms_helper]
 [<ffffffffa0171ed9>] drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x80 [drm_kms_helper]
 [<ffffffffa021c20e>] intel_fbdev_restore_mode+0x1e/0x50 [i915]
 [<ffffffffa02417ee>] i915_driver_lastclose+0xe/0x20 [i915]
 [<ffffffffa0053d0e>] drm_lastclose+0x2e/0x150 [drm]
 [<ffffffffa00540f8>] drm_release+0x2c8/0x4b0 [drm]
 [<ffffffff8121b5af>] __fput+0xdf/0x1f0
 [<ffffffff8121b70e>] ____fput+0xe/0x10
 [<ffffffff810b8a94>] task_work_run+0xd4/0xf0
 [<ffffffff8109e492>] do_exit+0x302/0xa70
 [<ffffffff811e237d>] ? free_pages_and_swap_cache+0x8d/0xa0
 [<ffffffff8109ec95>] do_group_exit+0x45/0xb0
 [<ffffffff810aa74c>] get_signal+0x27c/0x610
 [<ffffffff81014527>] do_signal+0x37/0x750
 [<ffffffff81369468>] ? blk_finish_plug+0x18/0x50
 [<ffffffff811e10f5>] ? SyS_madvise+0x3f5/0x850
 [<ffffffff81014ca9>] do_notify_resume+0x69/0xb0
 [<ffffffff81774ca7>] int_signal+0x12/0x17
Code: 33 71 e1 4c 89 e7 e8 17 b0 19 e1 48 83 c4 08 5b 41 5c 41 5d 5d c3 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 <0f> 0b 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 53 48 89 fb 48 
RIP  [<ffffffffa005f439>] drm_framebuffer_free_bug+0x9/0x10 [drm]
 RSP <ffff88022a157b18>

Potential duplicate: bug 1205650