Comment 3 for bug 1508826

58.996604] WARNING: CPU: 3 PID: 1891 at /build/linux-AxjFAn/linux-4.2.0/drivers/gpu/drm/i915/intel_crt.c:146 hsw_crt_pre_enable+0x7d/0x80 [i915]()
[ 58.996605] SPLL already enabled
[ 58.996606] Modules linked in: rfcomm ipt_REJECT nf_reject_ipv4 ebtable_filter ebtables ip6table_filter ip6_tables xt_addrtype xt_conntrack veth aufs xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack binfmt_misc xt_tcpudp bridge stp llc iptable_filter ip_tables x_tables bnep arc4 nls_iso8859_1 uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common videodev btusb iwlmvm btrtl media btbcm btintel bluetooth mac80211 intel_rapl snd_hda_codec_hdmi iosf_mbi x86_pkg_temp_thermal snd_hda_codec_realtek intel_powerclamp coretemp snd_hda_codec_generic iwlwifi input_leds joydev serio_raw cfg80211 thinkpad_acpi snd_seq_midi snd_hda_intel rtsx_pci_ms nvram memstick snd_hda_codec snd_seq_midi_event snd_hda_core
[ 58.996639] snd_rawmidi snd_hwdep mei_me mei snd_pcm ie31200_edac shpchp lpc_ich edac_core snd_seq wmi snd_seq_device kvm_intel snd_timer snd kvm soundcore mac_hid cuse parport_pc ppdev lp parport autofs4 btrfs drbg ansi_cprng algif_skcipher af_alg dm_crypt raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq raid1 raid0 multipath linear hid_microsoft hid_generic usbhid hid rtsx_pci_sdmmc crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel aes_x86_64 lrw i915 gf128mul glue_helper ablk_helper cryptd psmouse i2c_algo_bit drm_kms_helper ahci e1000e libahci drm ptp rtsx_pci pps_core video
[ 58.996673] CPU: 3 PID: 1891 Comm: Xorg Not tainted 4.2.0-16-generic #19-Ubuntu
[ 58.996674] Hardware name: LENOVO 20ANCTO1WW/20ANCTO1WW, BIOS GLET70WW (2.24 ) 05/21/2014
[ 58.996675] 0000000000000000 0000000015d91e38 ffff880437d1fa58 ffffffff817e8c09
[ 58.996678] 0000000000000000 ffff880437d1fab0 ffff880437d1fa98 ffffffff8107b3c6
[ 58.996679] 0000000000000046 ffff880434f00000 ffff880434c52100 ffff880435dee000
[ 58.996681] Call Trace:
[ 58.996687] [<ffffffff817e8c09>] dump_stack+0x45/0x57
[ 58.996691] [<ffffffff8107b3c6>] warn_slowpath_common+0x86/0xc0
[ 58.996693] [<ffffffff8107b455>] warn_slowpath_fmt+0x55/0x70
[ 58.996707] [<ffffffffc024d04d>] hsw_crt_pre_enable+0x7d/0x80 [i915]
[ 58.996719] [<ffffffffc0237108>] haswell_crtc_enable+0x418/0xa90 [i915]
[ 58.996730] [<ffffffffc0233fb6>] __intel_set_mode+0x916/0xb60 [i915]
[ 58.996742] [<ffffffffc023ad16>] intel_crtc_set_config+0x2b6/0x580 [i915]
[ 58.996753] [<ffffffffc004fee5>] ? drm_mode_create+0x25/0x60 [drm]
[ 58.996761] [<ffffffffc00494c6>] drm_mode_set_config_internal+0x66/0x100 [drm]
[ 58.996769] [<ffffffffc004db29>] drm_mode_setcrtc+0x3e9/0x500 [drm]
[ 58.996775] [<ffffffffc003e495>] drm_ioctl+0x125/0x610 [drm]
[ 58.996777] [<ffffffff8123e696>] ? fsnotify+0x316/0x4a0
[ 58.996784] [<ffffffffc004d740>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[ 58.996788] [<ffffffff812108a5>] do_vfs_ioctl+0x295/0x480
[ 58.996790] [<ffffffff81087f61>] ? __set_task_blocked+0x41/0xa0
[ 58.996792] [<ffffffff81210b09>] SyS_ioctl+0x79/0x90
[ 58.996795] [<ffffffff8108ab8e>] ? SyS_rt_sigprocmask+0x8e/0xc0
[ 58.996797] [<ffffffff817ef9f2>] entry_SYSCALL_64_fastpath+0x16/0x75