Description of problem:
after suspend

Additional info:
reporter:       libreport-2.2.3
WARNING: CPU: 0 PID: 3429 at drivers/gpu/drm/i915/intel_display.c:7365 hsw_enable_pc8+0x538/0x5d0 [i915]()
Power well on
Modules linked in: rfcomm ip6t_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack_ipv6 bnep nf_defrag_ipv6 xt_conntrack ip6table_filter nf_conntrack ip6_tables btusb bluetooth snd_hda_codec_realtek snd_hda_codec_generic iTCO_wdt snd_hda_codec_hdmi iTCO_vendor_support arc4 rtsx_pci_sdmmc fuse rtsx_pci_ms mmc_core pn544_mei mei_phy pn544 memstick hci x86_pkg_temp_thermal nfc coretemp kvm_intel uvcvideo videobuf2_vmalloc kvm iwlmvm videobuf2_memops mac80211 videobuf2_core v4l2_common crc32_pclmul videodev snd_hda_intel snd_hda_controller crc32c_intel media snd_hda_codec iwlwifi rtsx_pci serio_raw snd_hwdep cfg80211 snd_seq lpc_ich snd_seq_device toshiba_acpi mfd_core sparse_keymap rfkill snd_pcm toshiba_haps toshiba_bluetooth e1000e snd_timer wmi ptp snd mei_me pps_core mei soundcore i915 i2c_algo_bit drm_kms_helper drm video
CPU: 0 PID: 3429 Comm: kworker/u16:13 Not tainted 3.17.2-200.fc20.i686+PAE #1
Hardware name: TOSHIBA PORTEGE Z30-A/PORTEGE Z30-A, BIOS Version 3.70   07/25/2014
Workqueue: events_unbound async_run_entry_fn
 c0cd6947 f8046c4b 00000000 df3ebde8 c0a34a99 df3ebe28 df3ebe18 c0460c4e
 f86b58db df3ebe48 00000d65 f86abc48 00001cc5 f865f448 f865f448 f6b78000
 f682e9f8 f682e800 df3ebe34 c0460cae 00000009 df3ebe28 f86b58db df3ebe48
Call Trace:
 [<c0a34a99>] dump_stack+0x41/0x52
 [<c0460c4e>] warn_slowpath_common+0x7e/0xa0
 [<f865f448>] ? hsw_enable_pc8+0x538/0x5d0 [i915]
 [<f865f448>] ? hsw_enable_pc8+0x538/0x5d0 [i915]
 [<c0460cae>] warn_slowpath_fmt+0x3e/0x60
 [<f865f448>] hsw_enable_pc8+0x538/0x5d0 [i915]
 [<f860d1e3>] i915_pm_suspend_late+0x53/0x60 [i915]
 [<c07e1f96>] dpm_run_callback+0x46/0x100
 [<f860d190>] ? __i915_drm_thaw+0x190/0x190 [i915]
 [<c07e263a>] __device_suspend_late+0xaa/0x170
 [<c07e271f>] async_suspend_late+0x1f/0x90
 [<c047c335>] async_run_entry_fn+0x35/0x140
 [<c0485ccf>] ? wake_up_process+0x1f/0x40
 [<c0475747>] process_one_work+0x117/0x340
 [<c04b7eed>] ? try_to_del_timer_sync+0x4d/0x70
 [<c0475ccd>] worker_thread+0xed/0x3f0
 [<c0475be0>] ? rescuer_thread+0x270/0x270
 [<c0479e16>] kthread+0xa6/0xc0
 [<c0a3b181>] ret_from_kernel_thread+0x21/0x30
 [<c0479d70>] ? kthread_create_on_node+0x130/0x130