The display itself is working, but without backlight. If I preset a white background before DPMS, then turn off every light source in the room, and then wink a bit at the screen, I can see the display content, but there is no backlight. kernel: [ 7804.736123] ------------[ cut here ]------------ kernel: [ 7804.736146] WARNING: CPU: 1 PID: 4557 at drivers/gpu/drm/i915/intel_dp.c:3122 intel_dp_link_down+0x176/0x1e0 [i915]() kernel: [ 7804.736148] Modules linked in: pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) psmouse rfcomm bnep ipv6 iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat xt_tcpudp xt_limit nf_conntrack_ipv4 nf_defrag_ipv4 xt_multiport xt_conntrack nf_conntrack iptable_filter ip_tables x_tables nbd tun cpufreq_ondemand speedstep_lib lp fuse snd_hda_codec_hdmi i2c_dev i915 btusb x86_pkg_temp_thermal intel_powerclamp bluetooth nouveau ttm drm_kms_helper intel_gtt snd_hda_codec_realtek snd_hda_codec_generic coretemp processor drm joydev agpgart thermal video uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common snd_hda_intel thermal_sys videodev i2c_i801 sdhci_pci dell_laptop kvm_intel i2c_algo_bit sdhci mmc_core snd_hda_controller e1000e i2c_core ptp pps_core iwlwifi cfg80211 rfkill lpc_ich snd_hda_codec snd_hwdep snd_pcm ehci_pci snd_timer dell_wmi mxm_wmi sparse_keymap wmi ppdev serio_raw mei_me mei dcdbas evdev kvm snd soundcore ac battery button hwmon crc32_pclmul crc32c_intel microcode parport_pc parport loop hid_generic usbhid hid xhci_hcd ehci_hcd uhci_hcd [last unloaded: psmouse] kernel: [ 7804.736209] CPU: 1 PID: 4557 Comm: X Tainted: G W O 3.16.1-smp #31 kernel: [ 7804.736210] Hardware name: Dell Inc. Latitude E5440/08RCYC, BIOS A01 09/18/2013 kernel: [ 7804.736212] 00000000 00000000 edbdbcac c1b00807 00000000 edbdbcdc c1044d7e c1cbb48c kernel: [ 7804.736216] 00000001 000011cd fb5c49a0 00000c32 fb58fa16 fb58fa16 f0d38000 f10fbc80 kernel: [ 7804.736220] f10fa800 edbdbcec c1044e42 00000009 00000000 edbdbd14 fb58fa16 fb58f660 kernel: [ 7804.736224] Call Trace: kernel: [ 7804.736229] [<c1b00807>] dump_stack+0x41/0x52 kernel: [ 7804.736233] [<c1044d7e>] warn_slowpath_common+0x7e/0xa0 kernel: [ 7804.736245] [<fb58fa16>] ? intel_dp_link_down+0x176/0x1e0 [i915] kernel: [ 7804.736255] [<fb58fa16>] ? intel_dp_link_down+0x176/0x1e0 [i915] kernel: [ 7804.736258] [<c1044e42>] warn_slowpath_null+0x22/0x30 kernel: [ 7804.736268] [<fb58fa16>] intel_dp_link_down+0x176/0x1e0 [i915] kernel: [ 7804.736278] [<fb58f660>] ? intel_dp_dpcd_read_wake+0x30/0x50 [i915] kernel: [ 7804.736289] [<fb5946a7>] intel_dp_complete_link_train+0xd7/0x2e0 [i915] kernel: [ 7804.736300] [<fb58d390>] intel_ddi_pre_enable+0x110/0x190 [i915] kernel: [ 7804.736311] [<fb5774d2>] haswell_crtc_enable+0x372/0x920 [i915] kernel: [ 7804.736314] [<c1b07a64>] ? __ww_mutex_lock+0x14/0x75 kernel: [ 7804.736325] [<fb579228>] intel_crtc_update_dpms+0x78/0x90 [i915] kernel: [ 7804.736336] [<fb57ccad>] intel_connector_dpms+0x3d/0x60 [i915] kernel: [ 7804.736343] [<f989161f>] drm_mode_obj_set_property_ioctl+0x47f/0x4b0 [drm] kernel: [ 7804.736349] [<f988be25>] ? drm_modeset_unlock_all+0x35/0x60 [drm] kernel: [ 7804.736355] [<f9891683>] drm_mode_connector_property_set_ioctl+0x33/0x40 [drm] kernel: [ 7804.736360] [<f9891650>] ? drm_mode_obj_set_property_ioctl+0x4b0/0x4b0 [drm] kernel: [ 7804.736365] [<f98824bf>] drm_ioctl+0x1af/0x510 [drm] kernel: [ 7804.736368] [<c1058fce>] ? wake_up_worker+0x1e/0x30 kernel: [ 7804.736370] [<c105a974>] ? insert_work+0x54/0x90 kernel: [ 7804.736375] [<f9891650>] ? drm_mode_obj_set_property_ioctl+0x4b0/0x4b0 [drm] kernel: [ 7804.736379] [<c119ddc2>] ? sysfs_notify+0x42/0x80 kernel: [ 7804.736382] [<c15b542a>] ? backlight_generate_event+0x4a/0x60 kernel: [ 7804.736385] [<c15b5c50>] ? brightness_store+0x60/0xb0 kernel: [ 7804.736387] [<c15b5bf0>] ? fb_notifier_callback+0x110/0x110 kernel: [ 7804.736392] [<f9882310>] ? drm_ioctl_flags+0x40/0x40 [drm] kernel: [ 7804.736395] [<c114fa92>] do_vfs_ioctl+0x2f2/0x4d0 kernel: [ 7804.736397] [<c119d338>] ? kernfs_fop_release+0x38/0x40 kernel: [ 7804.736400] [<c156bd3b>] ? lockref_put_or_lock+0xb/0x30 kernel: [ 7804.736402] [<c1152dee>] ? dput+0x1e/0x140 kernel: [ 7804.736404] [<c115a0bd>] ? mntput+0x1d/0x30 kernel: [ 7804.736407] [<c1140cc4>] ? __fput+0x154/0x1b0 kernel: [ 7804.736410] [<c114fcd0>] SyS_ioctl+0x60/0x90 kernel: [ 7804.736413] [<c1b09492>] syscall_call+0x7/0x7 kernel: [ 7804.736415] [<c1b00000>] ? create_subvol+0x19f/0x7bf kernel: [ 7804.736417] ---[ end trace 195ee6eb1963d5d1 ]--- kernel: [ 7804.870301] ------------[ cut here ]------------ kernel: [ 7804.870313] WARNING: CPU: 1 PID: 4557 at drivers/gpu/drm/i915/intel_dp.c:3122 intel_dp_link_down+0x176/0x1e0 [i915]() kernel: [ 7804.870315] Modules linked in: pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) psmouse rfcomm bnep ipv6 iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat xt_tcpudp xt_limit nf_conntrack_ipv4 nf_defrag_ipv4 xt_multiport xt_conntrack nf_conntrack iptable_filter ip_tables x_tables nbd tun cpufreq_ondemand speedstep_lib lp fuse snd_hda_codec_hdmi i2c_dev i915 btusb x86_pkg_temp_thermal intel_powerclamp bluetooth nouveau ttm drm_kms_helper intel_gtt snd_hda_codec_realtek snd_hda_codec_generic coretemp processor drm joydev agpgart thermal video uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_core v4l2_common snd_hda_intel thermal_sys videodev i2c_i801 sdhci_pci dell_laptop kvm_intel i2c_algo_bit sdhci mmc_core snd_hda_controller e1000e i2c_core ptp pps_core iwlwifi cfg80211 rfkill lpc_ich snd_hda_codec snd_hwdep snd_pcm ehci_pci snd_timer dell_wmi mxm_wmi sparse_keymap wmi ppdev serio_raw mei_me mei dcdbas evdev kvm snd soundcore ac battery button hwmon crc32_pclmul crc32c_intel microcode parport_pc parport loop hid_generic usbhid hid xhci_hcd ehci_hcd uhci_hcd [last unloaded: psmouse] kernel: [ 7804.870362] CPU: 1 PID: 4557 Comm: X Tainted: G W O 3.16.1-smp #31 kernel: [ 7804.870363] Hardware name: Dell Inc. Latitude E5440/08RCYC, BIOS A01 09/18/2013 kernel: [ 7804.870364] 00000000 00000000 edbdbcac c1b00807 00000000 edbdbcdc c1044d7e c1cbb48c kernel: [ 7804.870368] 00000001 000011cd fb5c49a0 00000c32 fb58fa16 fb58fa16 f0d38000 f10fbc80 kernel: [ 7804.870372] f10fa800 edbdbcec c1044e42 00000009 00000000 edbdbd14 fb58fa16 fb58f660 kernel: [ 7804.870376] Call Trace: kernel: [ 7804.870379] [<c1b00807>] dump_stack+0x41/0x52 kernel: [ 7804.870382] [<c1044d7e>] warn_slowpath_common+0x7e/0xa0 kernel: [ 7804.870392] [<fb58fa16>] ? intel_dp_link_down+0x176/0x1e0 [i915] kernel: [ 7804.870402] [<fb58fa16>] ? intel_dp_link_down+0x176/0x1e0 [i915] kernel: [ 7804.870405] [<c1044e42>] warn_slowpath_null+0x22/0x30 kernel: [ 7804.870415] [<fb58fa16>] intel_dp_link_down+0x176/0x1e0 [i915] kernel: [ 7804.870425] [<fb58f660>] ? intel_dp_dpcd_read_wake+0x30/0x50 [i915] kernel: [ 7804.870435] [<fb5946a7>] intel_dp_complete_link_train+0xd7/0x2e0 [i915] kernel: [ 7804.870446] [<fb58d390>] intel_ddi_pre_enable+0x110/0x190 [i915] kernel: [ 7804.870457] [<fb5774d2>] haswell_crtc_enable+0x372/0x920 [i915] kernel: [ 7804.870459] [<c1b07a64>] ? __ww_mutex_lock+0x14/0x75 kernel: [ 7804.870470] [<fb579228>] intel_crtc_update_dpms+0x78/0x90 [i915] kernel: [ 7804.870480] [<fb57ccad>] intel_connector_dpms+0x3d/0x60 [i915] kernel: [ 7804.870486] [<f989161f>] drm_mode_obj_set_property_ioctl+0x47f/0x4b0 [drm] kernel: [ 7804.870492] [<f988be25>] ? drm_modeset_unlock_all+0x35/0x60 [drm] kernel: [ 7804.870498] [<f9891683>] drm_mode_connector_property_set_ioctl+0x33/0x40 [drm] kernel: [ 7804.870503] [<f9891650>] ? drm_mode_obj_set_property_ioctl+0x4b0/0x4b0 [drm] kernel: [ 7804.870507] [<f98824bf>] drm_ioctl+0x1af/0x510 [drm] kernel: [ 7804.870510] [<c1058fce>] ? wake_up_worker+0x1e/0x30 kernel: [ 7804.870512] [<c105a974>] ? insert_work+0x54/0x90 kernel: [ 7804.870517] [<f9891650>] ? drm_mode_obj_set_property_ioctl+0x4b0/0x4b0 [drm] kernel: [ 7804.870520] [<c119ddc2>] ? sysfs_notify+0x42/0x80 kernel: [ 7804.870523] [<c15b542a>] ? backlight_generate_event+0x4a/0x60 kernel: [ 7804.870525] [<c15b5c50>] ? brightness_store+0x60/0xb0 kernel: [ 7804.870528] [<c15b5bf0>] ? fb_notifier_callback+0x110/0x110 kernel: [ 7804.870532] [<f9882310>] ? drm_ioctl_flags+0x40/0x40 [drm] kernel: [ 7804.870535] [<c114fa92>] do_vfs_ioctl+0x2f2/0x4d0 kernel: [ 7804.870537] [<c119d338>] ? kernfs_fop_release+0x38/0x40 kernel: [ 7804.870539] [<c156bd3b>] ? lockref_put_or_lock+0xb/0x30 kernel: [ 7804.870541] [<c1152dee>] ? dput+0x1e/0x140 kernel: [ 7804.870543] [<c115a0bd>] ? mntput+0x1d/0x30 kernel: [ 7804.870546] [<c1140cc4>] ? __fput+0x154/0x1b0 kernel: [ 7804.870549] [<c114fcd0>] SyS_ioctl+0x60/0x90 kernel: [ 7804.870551] [<c1b09492>] syscall_call+0x7/0x7 kernel: [ 7804.870553] [<c1b00000>] ? create_subvol+0x19f/0x7bf kernel: [ 7804.870555] ---[ end trace 195ee6eb1963d5d2 ]--- $ lspci -v 00:00.0 Host bridge: Intel Corporation Haswell-ULT DRAM Controller (rev 0b) Subsystem: Dell Device 05de Flags: bus master, fast devsel, latency 0 Capabilities: <access denied> 00:02.0 VGA compatible controller: Intel Corporation Haswell-ULT Integrated Graphics Controller (rev 0b) (prog-if 00 [VGA controller]) Subsystem: Dell Device 05de Flags: bus master, fast devsel, latency 0, IRQ 62 Memory at f6400000 (64-bit, non-prefetchable) [size=4M] Memory at d0000000 (64-bit, prefetchable) [size=256M] I/O ports at f000 [size=64] Expansion ROM at <unassigned> [disabled] Capabilities: <access denied> Kernel driver in use: i915 Kernel modules: i915 00:03.0 Audio device: Intel Corporation Device 0a0c (rev 0b) Subsystem: Dell Device 05de Flags: bus master, fast devsel, latency 0, IRQ 63 Memory at f7434000 (64-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: snd_hda_intel Kernel modules: snd_hda_intel 00:14.0 USB controller: Intel Corporation Lynx Point-LP USB xHCI HC (rev 04) (prog-if 30 [XHCI]) Subsystem: Dell Device 05de Flags: bus master, medium devsel, latency 0, IRQ 57 Memory at f7420000 (64-bit, non-prefetchable) [size=64K] Capabilities: <access denied> Kernel driver in use: xhci_hcd Kernel modules: xhci_hcd 00:16.0 Communication controller: Intel Corporation Lynx Point-LP HECI #0 (rev 04) Subsystem: Dell Device 05de Flags: bus master, fast devsel, latency 0, IRQ 58 Memory at f743f000 (64-bit, non-prefetchable) [size=32] Capabilities: <access denied> Kernel driver in use: mei_me Kernel modules: mei_me 00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I218-LM (rev 04) Subsystem: Dell Device 05de Flags: bus master, fast devsel, latency 0, IRQ 59 Memory at f7400000 (32-bit, non-prefetchable) [size=128K] Memory at f743c000 (32-bit, non-prefetchable) [size=4K] I/O ports at f080 [size=32] Capabilities: <access denied> Kernel driver in use: e1000e Kernel modules: e1000e 00:1b.0 Audio device: Intel Corporation Lynx Point-LP HD Audio Controller (rev 04) Subsystem: Dell Device 05de Flags: bus master, fast devsel, latency 0, IRQ 60 Memory at f7430000 (64-bit, non-prefetchable) [size=16K] Capabilities: <access denied> Kernel driver in use: snd_hda_intel Kernel modules: snd_hda_intel 00:1c.0 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 1 (rev e4) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=01, subordinate=01, sec-latency=0 Memory behind bridge: f7300000-f73fffff Capabilities: <access denied> Kernel driver in use: pcieport Kernel modules: shpchp 00:1c.3 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 4 (rev e4) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=02, subordinate=02, sec-latency=0 Memory behind bridge: f7200000-f72fffff Capabilities: <access denied> Kernel driver in use: pcieport Kernel modules: shpchp 00:1c.4 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 5 (rev e4) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=03, subordinate=03, sec-latency=0 I/O behind bridge: 0000e000-0000efff Memory behind bridge: f5000000-f60fffff Prefetchable memory behind bridge: 00000000e0000000-00000000f1ffffff Capabilities: <access denied> Kernel driver in use: pcieport Kernel modules: shpchp 00:1c.5 PCI bridge: Intel Corporation Lynx Point-LP PCI Express Root Port 6 (rev e4) (prog-if 00 [Normal decode]) Flags: bus master, fast devsel, latency 0 Bus: primary=00, secondary=04, subordinate=04, sec-latency=0 I/O behind bridge: 0000d000-0000dfff Memory behind bridge: f6800000-f71fffff Prefetchable memory behind bridge: 00000000f2100000-00000000f2afffff Capabilities: <access denied> Kernel driver in use: pcieport Kernel modules: shpchp 00:1d.0 USB controller: Intel Corporation Lynx Point-LP USB EHCI #1 (rev 04) (prog-if 20 [EHCI]) Subsystem: Dell Device 05de Flags: bus master, medium devsel, latency 0, IRQ 21 Memory at f743b000 (32-bit, non-prefetchable) [size=1K] Capabilities: <access denied> Kernel driver in use: ehci-pci Kernel modules: ehci_pci 00:1f.0 ISA bridge: Intel Corporation Lynx Point-LP LPC Controller (rev 04) Subsystem: Dell Device 05de Flags: bus master, medium devsel, latency 0 Capabilities: <access denied> Kernel driver in use: lpc_ich Kernel modules: lpc_ich 00:1f.2 SATA controller: Intel Corporation Lynx Point-LP SATA Controller 1 [AHCI mode] (rev 04) (prog-if 01 [AHCI 1.0]) Subsystem: Dell Device 05de Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 56 I/O ports at f0d0 [size=8] I/O ports at f0c0 [size=4] I/O ports at f0b0 [size=8] I/O ports at f0a0 [size=4] I/O ports at f060 [size=32] Memory at f743a000 (32-bit, non-prefetchable) [size=2K] Capabilities: <access denied> Kernel driver in use: ahci 00:1f.3 SMBus: Intel Corporation Lynx Point-LP SMBus Controller (rev 04) Subsystem: Dell Device 05de Flags: medium devsel, IRQ 17 Memory at f7439000 (64-bit, non-prefetchable) [size=256] I/O ports at f040 [size=32] Kernel modules: i2c_i801 01:00.0 SD Host controller: O2 Micro, Inc. Device 8520 (rev 01) (prog-if 01) Subsystem: Dell Device 05de Flags: bus master, fast devsel, latency 0, IRQ 16 Memory at f7301000 (32-bit, non-prefetchable) [size=4K] Memory at f7300000 (32-bit, non-prefetchable) [size=2K] Capabilities: <access denied> Kernel driver in use: sdhci-pci Kernel modules: sdhci_pci 02:00.0 Network controller: Intel Corporation Intel(R) Dual Band Wireless-AC 7260 (rev 73) Subsystem: Intel Corporation Device 4470 Flags: fast devsel, IRQ 19 Memory at f7200000 (64-bit, non-prefetchable) [size=8K] Capabilities: <access denied> Kernel modules: iwlwifi 03:00.0 3D controller: NVIDIA Corporation GF117M [GeForce 610M/710M / GT 620M/625M/630M/720M] (rev a1) Subsystem: Dell Device 05de Flags: bus master, fast devsel, latency 0, IRQ 61 Memory at f5000000 (32-bit, non-prefetchable) [size=16M] Memory at e0000000 (64-bit, prefetchable) [size=256M] Memory at f0000000 (64-bit, prefetchable) [size=32M] I/O ports at e000 [size=128] Expansion ROM at f6000000 [disabled] [size=512K] Capabilities: <access denied> Kernel driver in use: nouveau Kernel modules: nvidiafb, nouveau
Is this a regression? If so, which kernel version worked?
This particular thing didn't happen before 3.16.0 (but I don't know about 3.16-rc versions).
(In reply to LÉVAI Dániel from comment #2) > This particular thing didn't happen before 3.16.0 (but I don't know about > 3.16-rc versions). Any chance of finding a good version and bisecting?
Given that every 3.16-rc before 3.16.0 boots me into a black screen, I can not do much for bisecting this, sorry guys. -- Daniel
(In reply to LÉVAI Dániel from comment #2) > This particular thing didn't happen before 3.16.0 (but I don't know about > 3.16-rc versions). What _thing_ didn't happen before 3.16, and why can't you bisect?
Wow. Really? So, the "thing", you know, that the bug report is about (as a matter of fact, in context, the "_thing_" was pretty understandable); the fact that backlight doesn't get switched on. > and why can't you bisect? >> Given that every 3.16-rc before 3.16.0 boots me into a black screen, >> I can not do much for bisecting this, sorry guys. -- Daniel
Which kernel version worked for you?
3.15.10 did not have this particular problem. -- Daniel
May I ask you to bisect between 3.15.10 and 3.16.0 please?
As I've stated in comment #4, I can not do the bisect, because many intermediate steps between 3.15.10 and 3.16 (including mainly 3.16 rcs) result in booting to a black screen, thus I can not tell if this particular problem would have persisted with the tried version. -- Daniel
Any idea what causes the black screen?
It turns black when it would switch to KMS, I think. -- Daniel
I guess bisect is a no go. Please attach dmesg with drm.debug=14 module parameter form boot to the problem.
...preferrably running as new a kernel you can get your hands on.
Nevermind; I had stopped using this hardware as its support gets worse with every kernel release.