Comment 9 for bug 1501260

I am also affected by this bug. My screen sometimes "randomly" freezes (when making a screenshot for example...) and this:

[drm:intel_pipe_config_compare [i915]] *ERROR* mismatch in dpll_hw_state.wrpll (expected 0xb035061f, found 0x00000000)

is written in console.

It always happens when I run glxgears. The screen is frozen with exception of the mouse cursor - it moves and changes shape when I hover a hyperlink or text. The system is responding, I is just not shown on the screen (I hope I am explaining this clearly). I can switch to console with ctrl+alt+f1, then killall glxgears, then alt+f7 everything is OK again. The actions that I did when the screen was frozen (like switching window, clicking a link...) are now visible.

#uname -a
Linux kevf14 4.2.0-23-generic #28-Ubuntu SMP Sun Dec 27 17:47:31 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

#dmesg

[1122359.632664] [drm:intel_pipe_config_compare [i915]] *ERROR* mismatch in dpll_hw_state.wrpll (expected 0xb035061f, found 0x00000000)
[1122359.632665] ------------[ cut here ]------------
[1122359.632674] WARNING: CPU: 0 PID: 8075 at /build/linux-AFqQDb/linux-4.2.0/drivers/gpu/drm/i915/intel_display.c:12328 check_crtc_state+0x2c5/0x440 [i915]()
[1122359.632675] pipe state doesn't match!
[1122359.632676] Modules linked in: nls_iso8859_1 pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) binfmt_misc usblp snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic intel_rapl iosf_mbi x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_intel input_leds snd_hda_codec kvm_intel snd_hda_core snd_hwdep kvm snd_pcm crct10dif_pclmul snd_seq_midi snd_seq_midi_event crc32_pclmul snd_rawmidi aesni_intel snd_seq aes_x86_64 lrw snd_seq_device gf128mul glue_helper snd_timer ablk_helper cryptd snd soundcore serio_raw mei_me lpc_ich mei shpchp 8250_fintek soc_button_array mac_hid tpm_infineon parport_pc ppdev lp parport autofs4 uas usb_storage hid_generic usbhid hid i915 i2c_algo_bit drm_kms_helper e1000e ahci psmouse drm libahci ptp pps_core video
[1122359.632695] CPU: 0 PID: 8075 Comm: Xorg Tainted: G W OE 4.2.0-23-generic #28-Ubuntu
[1122359.632696] Hardware name: Gigabyte Technology Co., Ltd. H87-D3H/H87-D3H-CF, BIOS F2 04/19/2013
[1122359.632697] 0000000000000000 0000000087e1737d ffff8803ec3e37c8 ffffffff817e94c9
[1122359.632698] 0000000000000000 ffff8803ec3e3820 ffff8803ec3e3808 ffffffff8107b3d6
[1122359.632699] ffff8803ec3e3848 ffff8803ec3e38b0 ffff88061c27d800 0000000000000001
[1122359.632701] Call Trace:
[1122359.632703] [<ffffffff817e94c9>] dump_stack+0x45/0x57
[1122359.632705] [<ffffffff8107b3d6>] warn_slowpath_common+0x86/0xc0
[1122359.632706] [<ffffffff8107b465>] warn_slowpath_fmt+0x55/0x70
[1122359.632714] [<ffffffffc01c7877>] ? intel_pipe_config_compare+0xa67/0xc60 [i915]
[1122359.632722] [<ffffffffc01c7d35>] check_crtc_state+0x2c5/0x440 [i915]
[1122359.632731] [<ffffffffc01dbb5d>] intel_modeset_check_state+0x21d/0x6d0 [i915]
[1122359.632738] [<ffffffffc01dcd17>] intel_crtc_set_config+0x4c7/0x580 [i915]
[1122359.632745] [<ffffffffc0047ef5>] ? drm_mode_create+0x25/0x60 [drm]
[1122359.632750] [<ffffffffc00414a6>] drm_mode_set_config_internal+0x66/0x100 [drm]
[1122359.632756] [<ffffffffc0045b39>] drm_mode_setcrtc+0x3e9/0x500 [drm]
[1122359.632760] [<ffffffffc0036495>] drm_ioctl+0x125/0x610 [drm]
[1122359.632761] [<ffffffff8123e8b6>] ? fsnotify+0x316/0x4a0
[1122359.632766] [<ffffffffc0045750>] ? drm_mode_setplane+0x1b0/0x1b0 [drm]
[1122359.632767] [<ffffffff81210aa5>] do_vfs_ioctl+0x295/0x480
[1122359.632769] [<ffffffff811ff875>] ? __sb_end_write+0x35/0x70
[1122359.632770] [<ffffffff811fd4aa>] ? vfs_write+0x15a/0x1a0
[1122359.632771] [<ffffffff81210d09>] SyS_ioctl+0x79/0x90
[1122359.632773] [<ffffffff817f02b2>] entry_SYSCALL_64_fastpath+0x16/0x75
[1122359.632774] ---[ end trace b3f56142f70d25bf ]---

#lspci

00:00.0 Host bridge: Intel Corporation 4th Gen Core Processor DRAM Controller (rev 06)
00:02.0 VGA compatible controller: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor Integrated Graphics Controller (rev 06)
00:03.0 Audio device: Intel Corporation Xeon E3-1200 v3/4th Gen Core Processor HD Audio Controller (rev 06)
00:14.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB xHCI (rev 04)
00:16.0 Communication controller: Intel Corporation 8 Series/C220 Series Chipset Family MEI Controller #1 (rev 04)
00:16.3 Serial controller: Intel Corporation 8 Series/C220 Series Chipset Family KT Controller (rev 04)
00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I217-V (rev 04)
00:1a.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #2 (rev 04)
00:1b.0 Audio device: Intel Corporation 8 Series/C220 Series Chipset High Definition Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #1 (rev d4)
00:1c.3 PCI bridge: Intel Corporation 82801 PCI Bridge (rev d4)
00:1d.0 USB controller: Intel Corporation 8 Series/C220 Series Chipset Family USB EHCI #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation H87 Express LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation 8 Series/C220 Series Chipset Family 6-port SATA Controller 1 [AHCI mode] (rev 04)
00:1f.3 SMBus: Intel Corporation 8 Series/C220 Series Chipset Family SMBus Controller (rev 04)
02:00.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 41)