Description of problem: report came up after booting Fedora 20 on a Samsung Ativ Book 9 Plus. Additional info: reporter: libreport-2.1.10 WARNING: CPU: 1 PID: 14 at drivers/gpu/drm/i915/intel_pm.c:5342 i915_request_power_well+0x77/0x80 [i915]() Modules linked in: r8169(+) mii snd_hda_intel(+) snd_hda_codec bluetooth snd_hwdep snd_seq snd_seq_device rfkill snd_pcm shpchp snd_page_alloc snd_timer snd mei_me mei soundcore wmi btrfs libcrc32c xor raid6_pq i915 i2c_algo_bit drm_kms_helper drm i2c_core video CPU: 1 PID: 14 Comm: kworker/1:0 Not tainted 3.12.5-301.fc20.x86_64 #1 Hardware name: SAMSUNG ELECTRONICS CO., LTD. 940X3G/NP940X3G-K04US, BIOS P02ACJ.101.130926.dg 09/26/2013 Workqueue: events azx_probe_work [snd_hda_intel] 0000000000000009 ffff880214283d58 ffffffff81663a7a 0000000000000000 ffff880214283d90 ffffffff8106925d ffff880211ba7a28 0000000000000000 0000000000000000 ffff880214342000 ffff880211ba7800 ffff880214283da0 Call Trace: [<ffffffff81663a7a>] dump_stack+0x45/0x56 [<ffffffff8106925d>] warn_slowpath_common+0x7d/0xa0 [<ffffffff8106933a>] warn_slowpath_null+0x1a/0x20 [<ffffffffa00dd567>] i915_request_power_well+0x77/0x80 [i915] [<ffffffffa0398bc2>] hda_display_power+0x32/0x40 [snd_hda_intel] [<ffffffffa0397571>] azx_probe_continue+0x41/0x940 [snd_hda_intel] [<ffffffffa0398955>] azx_probe_work+0x15/0x20 [snd_hda_intel] [<ffffffff810836e6>] process_one_work+0x176/0x430 [<ffffffff8108432b>] worker_thread+0x11b/0x3a0 [<ffffffff81084210>] ? rescuer_thread+0x350/0x350 [<ffffffff8108b1d0>] kthread+0xc0/0xd0 [<ffffffff8108b110>] ? insert_kthread_work+0x40/0x40 [<ffffffff81672a3c>] ret_from_fork+0x7c/0xb0 [<ffffffff8108b110>] ? insert_kthread_work+0x40/0x40
Created attachment 838681 [details] File: dmesg
note: System was having trouble booting (display would go blank when Fedora circle was half-way drawn), so I started system with "Single nomodeset", then this error came up after I logged in with GDM.
This issue happens also and on my computer too when I boot Live USB stick with Fedora 20 x64 in troubleshoot mode
$ 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) 00:1b.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.2 PCI bridge: Intel Corporation 8 Series/C220 Series Chipset Family PCI Express Root Port #3 (rev d4) 00:1c.3 PCI bridge: Intel Corporation 82801 PCI Bridge (rev d4) 00:1f.0 ISA bridge: Intel Corporation Z87 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 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 06) 03:00.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 41)
[ 5.160616] ------------[ cut here ]------------ [ 5.160633] WARNING: CPU: 7 PID: 117 at drivers/gpu/drm/i915/intel_pm.c:5098 i915_request_power_well+0x77/0x80 [i915]() [ 5.160647] Modules linked in: snd_hda_intel(+) btusb bluetooth snd_hda_codec snd_hwdep x86_pkg_temp_thermal snd_seq hid_logitech_dj joydev coretemp snd_seq_device kvm_intel rfkill kvm snd_pcm snd_page_alloc snd_timer ppdev snd iTCO_wdt parport_pc mei_me iTCO_vendor_support serio_raw mei parport soundcore i2c_i801 shpchp lpc_ich mfd_core acpi_cpufreq microcode mperf isofs squashfs usb_storage i915 i2c_algo_bit crc32_pclmul drm_kms_helper crc32c_intel drm ghash_clmulni_intel r8169 i2c_core mii video loop [ 5.160648] CPU: 7 PID: 117 Comm: kworker/7:1 Not tainted 3.11.10-301.fc20.x86_64 #1 [ 5.160649] Hardware name: Gigabyte Technology Co., Ltd. Z87M-D3H/Z87M-D3H, BIOS F8 08/03/2013 [ 5.160653] Workqueue: events azx_probe_work [snd_hda_intel] [ 5.160655] 0000000000000009 ffff88080d1f1d58 ffffffff816441db 0000000000000000 [ 5.160657] ffff88080d1f1d90 ffffffff8106715d ffff880812bbae28 0000000000000000 [ 5.160658] 0000000000000000 ffff880812bbac00 00000000000001c0 ffff88080d1f1da0 [ 5.160659] Call Trace: [ 5.160662] [<ffffffff816441db>] dump_stack+0x45/0x56 [ 5.160665] [<ffffffff8106715d>] warn_slowpath_common+0x7d/0xa0 [ 5.160666] [<ffffffff8106723a>] warn_slowpath_null+0x1a/0x20 [ 5.160676] [<ffffffffa0134487>] i915_request_power_well+0x77/0x80 [i915] [ 5.160679] [<ffffffffa0257a52>] hda_display_power+0x32/0x40 [snd_hda_intel] [ 5.160682] [<ffffffffa0256445>] azx_probe_continue+0x45/0x930 [snd_hda_intel] [ 5.160684] [<ffffffffa0257805>] azx_probe_work+0x15/0x20 [snd_hda_intel] [ 5.160687] [<ffffffff810810f5>] process_one_work+0x175/0x430 [ 5.160689] [<ffffffff81081d1b>] worker_thread+0x11b/0x3a0 [ 5.160690] [<ffffffff81081c00>] ? rescuer_thread+0x340/0x340 [ 5.160692] [<ffffffff81088660>] kthread+0xc0/0xd0 [ 5.160694] [<ffffffff810885a0>] ? insert_kthread_work+0x40/0x40 [ 5.160696] [<ffffffff8165332c>] ret_from_fork+0x7c/0xb0 [ 5.160697] [<ffffffff810885a0>] ? insert_kthread_work+0x40/0x40 [ 5.160698] ---[ end trace 3f24bb9c6c5a472c ]---
is it same bug as #1038487. I have this issue too.
You could try removing "nomodeset" from the kernel parameters at startup, by editing /etc/default/grub.conf and running grub-mkconfig -o /boot/grub/grub.cfg Apparently the i915 driver relies on kernel mode-setting and on my Acer E1-472, having it disabled resulted in this warning message as well as choppy video, the backlight controls not working and the display not powering up when resuming from sleep.