Comment 45 for bug 1492764

I also experience this in kubuntu 15.10 (upgrade), laptop hp g840

multiple traces of this type after boot

[ 19.491720] [drm:intel_pipe_config_compare [i915]] *ERROR* mismatch in ips_enabled (expected 1, found 0)
[ 19.491751] ------------[ cut here ]------------
[ 19.491764] WARNING: CPU: 2 PID: 1424 at /build/linux-jJX2Dm/linux-4.2.0/drivers/gpu/drm/i915/intel_display.c:12326 check_crtc_state+0x2c5/0x440 [i915]()
[ 19.491765] pipe state doesn't match!
[ 19.491765] Modules linked in: pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) binfmt_misc bnep nls_iso8859_1 arc4 hp_wmi sparse_keymap intel_rapl iosf_mbi x86_pkg_temp_thermal intel_powerclamp uvcvideo coretemp videobuf2_vmalloc crct10dif_pclmul videobuf2_memops btusb videobuf2_core btrtl crc32_pclmul v4l2_common ghash_clmulni_intel btbcm videodev btintel snd_hda_codec_hdmi bluetooth aesni_intel media snd_hda_codec_idt snd_hda_codec_generic aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd snd_hda_intel snd_hda_codec snd_hda_core iwlmvm snd_hwdep input_leds mac80211 joydev snd_pcm serio_raw snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq iwlwifi snd_seq_device snd_timer cfg80211 rtsx_pci_ms lpc_ich snd memstick mei_me mei shpchp soundcore 8250_fintek hp_accel lis3lv02d input_polldev
[ 19.491792] intel_smartconnect hp_wireless tpm_infineon mac_hid ip6t_REJECT nf_reject_ipv6 nf_log_ipv6 kvm_intel kvm xt_hl ip6t_rt nf_conntrack_ipv6 nf_defrag_ipv6 ipt_REJECT nf_reject_ipv4 nf_log_ipv4 nf_log_common xt_LOG xt_limit xt_tcpudp xt_addrtype nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack ip6table_filter ip6_tables nf_conntrack_netbios_ns nf_conntrack_broadcast nf_nat_ftp nf_nat nf_conntrack_ftp nf_conntrack iptable_filter ip_tables x_tables parport_pc ppdev lp parport autofs4 btrfs xor raid6_pq hid_generic usbhid hid rtsx_pci_sdmmc i915 rtsx_pci ahci i2c_algo_bit psmouse libahci drm_kms_helper e1000e drm ptp pps_core wmi video
[ 19.491814] CPU: 2 PID: 1424 Comm: Xorg Tainted: G W OE 4.2.0-18-generic #22-Ubuntu
[ 19.491815] Hardware name: Hewlett-Packard HP EliteBook 840 G1/198F, BIOS L71 Ver. 01.30 12/09/2014
[ 19.491816] 0000000000000000 0000000044c43655 ffff88032c2c3878 ffffffff817e8c09
[ 19.491818] 0000000000000000 ffff88032c2c38d0 ffff88032c2c38b8 ffffffff8107b3c6
[ 19.491819] ffff88032c2c38f8 ffff88032c2c3960 ffff88032aa5a800 0000000000000001
[ 19.491821] Call Trace:
[ 19.491823] [<ffffffff817e8c09>] dump_stack+0x45/0x57
[ 19.491826] [<ffffffff8107b3c6>] warn_slowpath_common+0x86/0xc0
[ 19.491828] [<ffffffff8107b455>] warn_slowpath_fmt+0x55/0x70
[ 19.491841] [<ffffffffc0268bc1>] ? intel_pipe_config_compare+0xb31/0xc60 [i915]
[ 19.491853] [<ffffffffc0268fb5>] check_crtc_state+0x2c5/0x440 [i915]
[ 19.491867] [<ffffffffc027cd6d>] intel_modeset_check_state+0x21d/0x6d0 [i915]
[ 19.491880] [<ffffffffc027df27>] intel_crtc_set_config+0x4c7/0x580 [i915]
[ 19.491888] [<ffffffffc003d4c6>] drm_mode_set_config_internal+0x66/0x100 [drm]
[ 19.491892] [<ffffffffc00fd632>] restore_fbdev_mode+0xc2/0xf0 [drm_kms_helper]
[ 19.491897] [<ffffffffc00ff4e9>] drm_fb_helper_restore_fbdev_mode_unlocked+0x29/0x70 [drm_kms_helper]
[ 19.491909] [<ffffffffc028c07e>] intel_fbdev_restore_mode+0x1e/0x50 [i915]
[ 19.491923] [<ffffffffc02b5a9e>] i915_driver_lastclose+0xe/0x20 [i915]
[ 19.491929] [<ffffffffc003096e>] drm_lastclose+0x2e/0x140 [drm]
[ 19.491934] [<ffffffffc0030d96>] drm_release+0x316/0x500 [drm]
[ 19.491936] [<ffffffff811fee84>] __fput+0xe4/0x220
[ 19.491938] [<ffffffff811ff00e>] ____fput+0xe/0x10
[ 19.491939] [<ffffffff81098b55>] task_work_run+0x85/0xb0
[ 19.491942] [<ffffffff81014ea9>] do_notify_resume+0x69/0x70
[ 19.491944] [<ffffffff817efbc4>] int_signal+0x12/0x17
[ 19.491945] ---[ end trace bff15b000dbe1aca ]---