Hi Ander, I reported this bug on https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1420290 As my updates there don't appear here, I'm posting here also. Sander Snippet from around the flip message: [ 7538.988560] [drm:valleyview_update_wm] Setting FIFO watermarks - A: plane=111, cursor=2, B: plane=2, cursor=2, SR: plane=60, cursor=2 [ 7538.988565] [drm:intel_set_memory_cxsr] memory self-refresh is enabled [ 7538.994556] [drm:g4x_check_srwm] SR watermark: display plane 60, cursor 6 [ 7538.994563] [drm:g4x_check_srwm] SR watermark: display plane 117, cursor 10 [ 7538.994568] [drm:valleyview_update_wm] Setting FIFO watermarks - A: plane=111, cursor=6, B: plane=2, cursor=2, SR: plane=60, cursor=10 [ 7538.994572] [drm:intel_set_memory_cxsr] memory self-refresh is enabled [ 7540.057903] [drm:i915_gem_context_destroy_ioctl] HW context 25 destroyed [ 7543.835009] wlan0: deauthenticating from c0:4a:00:2c:dc:bd by local choice (Reason: 3=DEAUTH_LEAVING) [ 7543.848742] cfg80211: Calling CRDA to update world regulatory domain [ 7543.932927] cfg80211: World regulatory domain updated: [ 7543.932935] cfg80211: DFS Master region: unset [ 7543.932937] cfg80211: (start_freq - end_freq @ bandwidth), (max_antenna_gain, max_eirp), (dfs_cac_time) [ 7543.932943] cfg80211: (2402000 KHz - 2472000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A) [ 7543.932947] cfg80211: (2457000 KHz - 2482000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A) [ 7543.932950] cfg80211: (2474000 KHz - 2494000 KHz @ 20000 KHz), (300 mBi, 2000 mBm), (N/A) [ 7543.932953] cfg80211: (5170000 KHz - 5250000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A) [ 7543.932957] cfg80211: (5735000 KHz - 5835000 KHz @ 40000 KHz), (300 mBi, 2000 mBm), (N/A) [ 7545.299524] wlan0: authenticate with 00:14:7f:b2:ad:fd [ 7545.311204] wlan0: send auth to 00:14:7f:b2:ad:fd (try 1/3) [ 7545.313850] wlan0: authenticated [ 7545.329704] wlan0: associate with 00:14:7f:b2:ad:fd (try 1/3) [ 7545.333311] wlan0: RX AssocResp from 00:14:7f:b2:ad:fd (capab=0x411 status=0 aid=5) [ 7545.334296] wlan0: associated [ 7591.802174] ------------[ cut here ]------------ [ 7591.802224] WARNING: CPU: 0 PID: 0 at /build/buildd/linux-3.19.0/drivers/gpu/drm/i915/intel_display.c:9713 intel_check_page_flip+0xda/0xf0 [i915]() [ 7591.802227] Kicking stuck page flip: queued at 453978, now 453983 [ 7591.802229] Modules linked in: ctr ccm rfcomm bnep nls_iso8859_1 hid_generic hp_wmi sparse_keymap btusb bluetooth usbhid joydev snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic intel_rapl intel_soc_dts_thermal intel_powerclamp coretemp kvm_intel kvm crct10dif_pclmul crc32_pclmul ghash_clmulni_intel cryptd arc4 uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core rtl8723be v4l2_common btcoexist videodev rtl8723_common rtl_pci media rtlwifi mac80211 snd_hda_intel serio_raw snd_hda_controller cfg80211 snd_intel_sst_acpi snd_intel_sst_core snd_soc_rt5640 snd_soc_sst_mfld_platform mei_txe i915 snd_hda_codec snd_soc_rl6231 rtsx_pci_ms lpc_ich memstick snd_soc_core shpchp snd_compress snd_pcm_dmaengine snd_hwdep mei snd_pcm drm_kms_helper drm snd_seq_midi snd_seq_midi_event iosf_mbi [ 7591.802283] i2c_algo_bit wmi snd_rawmidi snd_seq snd_seq_device video hp_wireless dw_dmac dw_dmac_core snd_timer processor_thermal_device int3403_thermal int3400_thermal acpi_thermal_rel intel_smartconnect snd i2c_hid hid soundcore rfkill_gpio i2c_designware_platform i2c_designware_core snd_soc_sst_acpi 8250_dw spi_pxa2xx_platform pwm_lpss_platform mac_hid pwm_lpss parport_pc ppdev lp parport autofs4 mmc_block rtsx_pci_sdmmc psmouse rtsx_pci sdhci_acpi sdhci [ 7591.802322] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 3.19.0-16-generic #16-Ubuntu [ 7591.802324] Hardware name: Hewlett-Packard HP Stream Notebook PC 13/802A, BIOS F.06 01/06/2015 [ 7591.802327] ffffffffc0559e10 ffff880076c03d18 ffffffff817c2235 0000000000000007 [ 7591.802332] ffff880076c03d68 ffff880076c03d58 ffffffff8107595a ffff880076c03d78 [ 7591.802336] ffff880071d65000 ffff88003671b000 0000000000000000 ffff88003671b1a8 [ 7591.802341] Call Trace: [ 7591.802344] [] dump_stack+0x45/0x57 [ 7591.802358] [] warn_slowpath_common+0x8a/0xc0 [ 7591.802363] [] warn_slowpath_fmt+0x46/0x50 [ 7591.802390] [] intel_check_page_flip+0xda/0xf0 [i915] [ 7591.802413] [] valleyview_pipestat_irq_handler+0x159/0x230 [i915] [ 7591.802437] [] valleyview_irq_handler+0xc1/0x170 [i915] [ 7591.802443] [] handle_irq_event_percpu+0x77/0x1a0 [ 7591.802447] [] handle_irq_event+0x41/0x70 [ 7591.802452] [] handle_edge_irq+0x6e/0x120 [ 7591.802457] [] handle_irq+0x22/0x40 [ 7591.802462] [] do_IRQ+0x4f/0xf0 [ 7591.802467] [] common_interrupt+0x6d/0x6d [ 7591.802469] [] ? cpuidle_enter_state+0x65/0x160 [ 7591.802478] [] ? cpuidle_enter_state+0x51/0x160 [ 7591.802482] [] cpuidle_enter+0x17/0x20 [ 7591.802487] [] cpu_startup_entry+0x311/0x3b0 [ 7591.802492] [] rest_init+0x77/0x80 [ 7591.802498] [] start_kernel+0x482/0x48f [ 7591.802502] [] ? early_idt_handlers+0x120/0x120 [ 7591.802507] [] x86_64_start_reservations+0x2a/0x2c [ 7591.802511] [] x86_64_start_kernel+0x143/0x152 [ 7591.802514] ---[ end trace eb45f1b701243f9b ]--- [ 7666.909632] atkbd serio0: Unknown key pressed (translated set 2, code 0xd8 on isa0060/serio0). [ 7666.909640] atkbd serio0: Use 'setkeycodes e058 ' to make it known. [ 7666.917627] atkbd serio0: Unknown key released (translated set 2, code 0xd8 on isa0060/serio0). [ 7666.917634] atkbd serio0: Use 'setkeycodes e058 ' to make it known. [ 7667.193969] [drm:intel_dp_detect] [CONNECTOR:35:DP-1] [ 7667.194050] [drm:intel_hdmi_detect] [CONNECTOR:30:HDMI-A-1] [ 7667.194224] [drm:gmbus_xfer] GMBUS [i915 gmbus dpb] NAK for addr: 0050 r(1) [ 7667.194230] [drm:drm_do_probe_ddc_edid] drm: skipping non-existent adapter i915 gmbus dpb [ 7667.194356] [drm:intel_hdmi_detect] [CONNECTOR:37:HDMI-A-2] [ 7667.194638] [drm:drm_do_probe_ddc_edid] drm: skipping non-existent adapter i915 gmbus dpc [ 7667.194714] [drm:intel_crt_detect] [CONNECTOR:27:VGA-1] force=1 [ 7667.194719] [drm:valleyview_crt_detect_hotplug] trigger hotplug detect cycle: adpa=0xf40000 [ 7667.202343] [drm:valleyview_crt_detect_hotplug] valleyview hotplug adpa=0xf40000, result 0 [ 7667.202349] [drm:intel_crt_detect] CRT not detected via hotplug [ 7667.204040] [drm:drm_mode_getconnector] [CONNECTOR:39:?]