Running "3.19.0-994-generic #201502112105" from http://kernel.ubuntu.com/~kernel-ppa/mainline/drm-intel-nightly/2015-02-12-vivid/ and now dmesg shows a warning in a different line of intel_display.c:


[ 2702.807816] WARNING: CPU: 0 PID: 3 at /home/kernel/COD/linux/drivers/gpu/drm/i915/intel_display.c:9698 intel_check_page_flip+0xe6/0xf0 [i915]()



[ 2702.807734] ------------[ cut here ]------------
[ 2702.807816] WARNING: CPU: 0 PID: 3 at /home/kernel/COD/linux/drivers/gpu/drm/i915/intel_display.c:9698 intel_check_page_flip+0xe6/0xf0 [i915]()
[ 2702.807822] Kicking stuck page flip: queued at 161538, now 161547
[ 2702.807827] Modules linked in: hp_wmi sparse_keymap hid_generic intel_rapl intel_soc_dts_thermal intel_powerclamp coretemp btusb kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel cryptd arc4 joydev rtl8723be btcoexist snd_hda_codec_hdmi serio_raw rtl8723_common rtl_pci snd_hda_codec_realtek snd_hda_codec_generic i915 uvcvideo rtlwifi snd_intel_sst_acpi videobuf2_vmalloc snd_intel_sst_core videobuf2_memops snd_soc_rt5640 mac80211 snd_soc_sst_mfld_platform videobuf2_core rtsx_pci_ms snd_soc_rl6231 v4l2_common snd_hda_intel cfg80211 memstick drm_kms_helper snd_hda_controller snd_soc_core snd_compress snd_hda_codec videodev media snd_hwdep snd_pcm_dmaengine drm snd_pcm snd_seq_midi iosf_mbi snd_seq_midi_event i2c_algo_bit lpc_ich mei_txe shpchp mei wmi snd_rawmidi snd_seq snd_seq_device
[ 2702.807936]  snd_timer video hp_wireless dw_dmac dw_dmac_core snd rfcomm bnep usbhid int3403_thermal processor_thermal_device int3400_thermal acpi_thermal_rel bluetooth i2c_hid intel_smartconnect hid soundcore rfkill_gpio snd_soc_sst_acpi i2c_designware_platform i2c_designware_core pwm_lpss_platform spi_pxa2xx_platform 8250_dw pwm_lpss parport_pc mac_hid ppdev lp parport nls_iso8859_1 mmc_block rtsx_pci_sdmmc psmouse rtsx_pci sdhci_acpi sdhci
[ 2702.808006] CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 3.19.0-994-generic #201502112105
[ 2702.808011] Hardware name: Hewlett-Packard HP Stream Notebook PC 13/802A, BIOS F.05 11/28/2014
[ 2702.808017]  00000000000025e2 ffff880076c03d08 ffffffff817c5530 0000000000000007
[ 2702.808027]  ffff880076c03d58 ffff880076c03d48 ffffffff81076e87 0000000000000a8c
[ 2702.808036]  ffff880073405000 ffff88007315c9a8 ffff88007315c800 0000000000000000
[ 2702.808045] Call Trace:
[ 2702.808050]  <IRQ>  [<ffffffff817c5530>] dump_stack+0x45/0x57
[ 2702.808075]  [<ffffffff81076e87>] warn_slowpath_common+0x97/0xe0
[ 2702.808084]  [<ffffffff81076f86>] warn_slowpath_fmt+0x46/0x50
[ 2702.808145]  [<ffffffffc07dc086>] intel_check_page_flip+0xe6/0xf0 [i915]
[ 2702.808195]  [<ffffffffc079e388>] valleyview_pipestat_irq_handler+0x188/0x220 [i915]
[ 2702.808246]  [<ffffffffc07a4b1f>] valleyview_irq_handler+0xaf/0x180 [i915]
[ 2702.808258]  [<ffffffff810ce4cd>] handle_irq_event_percpu+0x5d/0x1e0
[ 2702.808267]  [<ffffffff810ce698>] handle_irq_event+0x48/0x70
[ 2702.808276]  [<ffffffff810d171f>] handle_edge_irq+0x7f/0x120
[ 2702.808285]  [<ffffffff810178a2>] handle_irq+0x22/0x40
[ 2702.808295]  [<ffffffff817d578c>] do_IRQ+0x5c/0x110
[ 2702.808304]  [<ffffffff817d35ed>] common_interrupt+0x6d/0x6d
[ 2702.808309]  <EOI>  [<ffffffffc0910002>] ? rtl8723be_card_disable+0x32/0x80 [rtl8723be]
[ 2702.808333]  [<ffffffffc0725030>] ? pci_read16_sync+0x10/0x20 [rtl_pci]
[ 2702.808347]  [<ffffffffc0918a83>] rtl8723be_tx_polling+0x53/0x60 [rtl8723be]
[ 2702.808358]  [<ffffffffc07254f9>] rtl_pci_tx+0x1e9/0x430 [rtl_pci]
[ 2702.808374]  [<ffffffffc08ae5e9>] ? rtl_get_tcb_desc+0x169/0x360 [rtlwifi]
[ 2702.808417]  [<ffffffffc066916b>] ? rate_control_apply_mask.isra.10+0x6b/0x1c0 [mac80211]
[ 2702.808453]  [<ffffffffc05b7324>] ? ieee80211_get_hdrlen_from_skb+0x24/0x40 [cfg80211]
[ 2702.808469]  [<ffffffffc08b1e22>] rtl_op_tx+0xb2/0xc0 [rtlwifi]
[ 2702.808510]  [<ffffffffc0678c02>] ieee80211_tx_frags+0xd2/0x200 [mac80211]
[ 2702.808551]  [<ffffffffc0678db3>] __ieee80211_tx+0x83/0x190 [mac80211]
[ 2702.808592]  [<ffffffffc067bd62>] ieee80211_tx+0xd2/0x100 [mac80211]
[ 2702.808635]  [<ffffffffc067bf02>] ieee80211_xmit+0xa2/0x110 [mac80211]
[ 2702.808676]  [<ffffffffc067c340>] __ieee80211_subif_start_xmit+0x90/0xb0 [mac80211]
[ 2702.808718]  [<ffffffffc067c370>] ieee80211_subif_start_xmit+0x10/0x20 [mac80211]
[ 2702.808728]  [<ffffffff816b3660>] xmit_one+0x70/0x150
[ 2702.808738]  [<ffffffff816a07e0>] ? skb_ts_get_next_block+0x20/0x20
[ 2702.808748]  [<ffffffff816afd00>] ? skb_checksum_help+0x40/0x1e0
[ 2702.808757]  [<ffffffff816b657b>] dev_hard_start_xmit+0x4b/0xa0
[ 2702.808768]  [<ffffffff816d7e8a>] sch_direct_xmit+0x10a/0x1e0
[ 2702.808778]  [<ffffffff816b677c>] __dev_queue_xmit+0x1ac/0x560
[ 2702.808786]  [<ffffffff816b6b50>] dev_queue_xmit+0x10/0x20
[ 2702.808797]  [<ffffffff8175b5a4>] ip6_finish_output2+0x1c4/0x4b0
[ 2702.808807]  [<ffffffff810af74f>] ? enqueue_entity+0x2bf/0x570
[ 2702.808817]  [<ffffffff8175e075>] ip6_finish_output+0x95/0xd0
[ 2702.808826]  [<ffffffff8175e0ee>] ip6_output+0x3e/0xb0
[ 2702.808835]  [<ffffffff8176a1f7>] ? ip6_dst_check+0x27/0x50
[ 2702.808845]  [<ffffffff8175baba>] ip6_xmit+0x22a/0x490
[ 2702.808855]  [<ffffffff8178d097>] inet6_csk_xmit+0x77/0xc0
[ 2702.808866]  [<ffffffff8170d745>] tcp_transmit_skb+0x335/0x580
[ 2702.808875]  [<ffffffff816a290b>] ? __alloc_skb+0x9b/0x2b0
[ 2702.808885]  [<ffffffff8170dbc1>] tcp_send_ack+0x121/0x170
[ 2702.808894]  [<ffffffff81702b9e>] __tcp_ack_snd_check+0x5e/0xa0
[ 2702.808903]  [<ffffffff81709518>] tcp_rcv_established+0x228/0x740
[ 2702.808912]  [<ffffffff81786a56>] tcp_v6_do_rcv+0x216/0x450
[ 2702.808922]  [<ffffffff81312226>] ? security_sock_rcv_skb+0x16/0x20
[ 2702.808931]  [<ffffffff81787bf6>] tcp_v6_rcv+0x796/0x7e0
[ 2702.808940]  [<ffffffff817155d7>] ? tcp_v4_rcv+0x837/0x8a0
[ 2702.808950]  [<ffffffff8175e350>] ip6_input_finish+0x140/0x420
[ 2702.808958]  [<ffffffff8175eb32>] ip6_input+0x22/0x60
[ 2702.808966]  [<ffffffff81785888>] ? tcp_v6_early_demux+0x58/0x70
[ 2702.808976]  [<ffffffff8175e1d8>] ip6_rcv_finish+0x78/0xb0
[ 2702.808984]  [<ffffffff8175e927>] ipv6_rcv+0x2f7/0x4e0
[ 2702.808993]  [<ffffffff816b4593>] __netif_receive_skb_core+0x513/0x670
[ 2702.809002]  [<ffffffff816b4711>] __netif_receive_skb+0x21/0x70
[ 2702.809011]  [<ffffffff816b48d3>] netif_receive_skb_internal+0x23/0x90
[ 2702.809019]  [<ffffffff816b496d>] netif_receive_skb+0x2d/0x80
[ 2702.809059]  [<ffffffffc0674113>] ieee80211_deliver_skb+0x133/0x250 [mac80211]
[ 2702.809100]  [<ffffffffc06758d8>] ieee80211_rx_h_data+0x1a8/0x2b0 [mac80211]
[ 2702.809140]  [<ffffffffc0676ea5>] ieee80211_rx_handlers+0x115/0x1e0 [mac80211]
[ 2702.809180]  [<ffffffffc067704f>] ieee80211_prepare_and_rx_handle+0xdf/0x130 [mac80211]
[ 2702.809221]  [<ffffffffc0677257>] __ieee80211_rx_handle_packet+0x1b7/0x360 [mac80211]
[ 2702.809262]  [<ffffffffc0677515>] ieee80211_rx+0x115/0x240 [mac80211]
[ 2702.809294]  [<ffffffffc0650324>] ieee80211_tasklet_handler+0xd4/0xe0 [mac80211]
[ 2702.809303]  [<ffffffff8107b307>] tasklet_action+0xc7/0xe0
[ 2702.809311]  [<ffffffff8107ac9e>] __do_softirq+0xde/0x2d0
[ 2702.809320]  [<ffffffff8107aebd>] run_ksoftirqd+0x2d/0x50
[ 2702.809329]  [<ffffffff81099866>] smpboot_thread_fn+0x116/0x170
[ 2702.809338]  [<ffffffff81099750>] ? SyS_setgroups+0x160/0x160
[ 2702.809347]  [<ffffffff81095d59>] kthread+0xc9/0xe0
[ 2702.809356]  [<ffffffff81095c90>] ? flush_kthread_worker+0x90/0x90
[ 2702.809364]  [<ffffffff817d27bc>] ret_from_fork+0x7c/0xb0
[ 2702.809373]  [<ffffffff81095c90>] ? flush_kthread_worker+0x90/0x90
[ 2702.809380] ---[ end trace 7ea75ef51a646f5a ]---