Whenever I try to change the backlight brightness with the fn+f1 or fn+f2 keys, the gui does show that the brightness is being adjusted. However the actual brightness stays the same, until I get to the absolute lowest value possible, then the backlight just turns off completely (which I can then turn back on again by increasing the brightness again). I've also changed my grub settings as suggested by this question but that doesn't fix things for me.
When I look at /sys/class/backlight I only have the intel_backlight folder. When try echo'ing into the brightness file inside that folder (as suggested by some other answers on here) I get the same result as with the fn keys: the backlight stays at maximum brightness until I enter 0 as a value, then it just turns off.
I'm currently on 14.10, but I had the same problem in 14.04. Is there any way I can fix this, even if it's just a manual way of controlling the brightness, since then I can at least look at my screen again without burning my retinas.
EDIT:
~$ sudo lshw -C Display
*-display
description: VGA compatible controller
product: 3rd Gen Core processor Graphics Controller
vendor: Intel Corporation
physical id: 2
bus info: pci@0000:00:02.0
version: 09
width: 64 bits
clock: 33MHz
capabilities: msi pm vga_controller bus_master cap_list rom
configuration: driver=i915 latency=0
resources: irq:45 memory:f7800000-f7bfffff memory:e0000000-efffffff ioport:f000(size=64)
and
~$ lsmod
Module Size Used by
ctr 13049 1
ccm 17731 1
bnep 19543 2
rfcomm 69509 8
binfmt_misc 17468 1
nls_iso8859_1 12713 1
uvcvideo 81065 0
videobuf2_vmalloc 13216 1 uvcvideo
videobuf2_memops 13362 1 videobuf2_vmalloc
videobuf2_core 59104 1 uvcvideo
v4l2_common 15682 1 videobuf2_core
videodev 149725 3 uvcvideo,v4l2_common,videobuf2_core
media 21963 2 uvcvideo,videodev
arc4 12608 2
iwldvm 236430 0
mac80211 660592 1 iwldvm
snd_hda_codec_hdmi 47547 1
snd_hda_codec_realtek 76887 1
snd_hda_codec_generic 68914 1 snd_hda_codec_realtek
intel_rapl 18783 0
x86_pkg_temp_thermal 14205 0
intel_powerclamp 18786 0
coretemp 13441 0
dm_multipath 22843 0
kvm_intel 143553 0
scsi_dh 14882 1 dm_multipath
kvm 459843 1 kvm_intel
crct10dif_pclmul 14307 0
snd_hda_intel 30379 5
crc32_pclmul 13133 0
snd_hda_controller 35152 1 snd_hda_intel
ghash_clmulni_intel 13230 0
snd_hda_codec 139675 5
snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_hda_intel,snd_hda_c ontroller
snd_hwdep 17698 1 snd_hda_codec
aesni_intel 152552 2
aes_x86_64 17131 1 aesni_intel
lrw 13287 1 aesni_intel
gf128mul 14951 1 lrw
glue_helper 13944 1 aesni_intel
ablk_helper 13597 1 aesni_intel
cryptd 20360 3 ghash_clmulni_intel,aesni_intel,ablk_helper
snd_pcm 104102 5 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel,snd_hda_controller
snd_seq_midi 13564 0
snd_seq_midi_event 14899 1 snd_seq_midi
snd_rawmidi 30876 1 snd_seq_midi
joydev 17344 0
snd_seq 67224 2 snd_seq_midi_event,snd_seq_midi
serio_raw 13434 0
snd_seq_device 14497 3 snd_seq,snd_rawmidi,snd_seq_midi
snd_timer 29513 2 snd_pcm,snd_seq
iwlwifi 182909 1 iwldvm
snd 87611 20 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_seq,snd_rawmi di,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel,snd_seq_device
lpc_ich 21093 0
cfg80211 510218 3 iwlwifi,mac80211,iwldvm
btusb 32448 0
bluetooth 446190 22 bnep,btusb,rfcomm
mei_me 19742 0
mei 87931 1 mei_me
shpchp 37040 0
soundcore 15052 2 snd,snd_hda_codec
6lowpan_iphc 18702 1 bluetooth
mac_hid 13227 0
parport_pc 32741 0
ppdev 17671 0
lp 17759 0
parport 42299 3 lp,ppdev,parport_pc
btrfs 911467 0
xor 21411 1 btrfs
raid6_pq 97812 1 btrfs
dm_mirror 22040 0
dm_region_hash 20850 1 dm_mirror
dm_log 18411 2 dm_region_hash,dm_mirror
i915 917618 4
i2c_algo_bit 13406 1 i915
psmouse 106548 0
drm_kms_helper 61627 1 i915
r8169 71471 0
mii 13934 1 r8169
drm 310919 6 i915,drm_kms_helper
ahci 34062 3
libahci 32424 1 ahci
wmi 19193 0
video 20128 1 i915
and
~$ modinfo i915
filename: /lib/modules/3.16.0-24-generic/kernel/drivers/gpu/drm/i915/i915.ko
license: GPL and additional rights
description: Intel Graphics
author: Tungsten Graphics, Inc.
srcversion: 05B59F886C9F39DA145FE73
alias: pci:v00008086d000022B3sv*sd*bc03sc*i*
alias: pci:v00008086d000022B2sv*sd*bc03sc*i*
alias: pci:v00008086d000022B1sv*sd*bc03sc*i*
alias: pci:v00008086d000022B0sv*sd*bc03sc*i*
alias: pci:v00008086d0000162Dsv*sd*bc03sc*i*
alias: pci:v00008086d0000162Asv*sd*bc03sc*i*
alias: pci:v00008086d0000162Esv*sd*bc03sc*i*
alias: pci:v00008086d0000162Bsv*sd*bc03sc*i*
alias: pci:v00008086d00001626sv*sd*bc03sc*i*
alias: pci:v00008086d00001622sv*sd*bc03sc*i*
alias: pci:v00008086d0000161Dsv*sd*bc03sc*i*
alias: pci:v00008086d0000161Asv*sd*bc03sc*i*
alias: pci:v00008086d0000160Dsv*sd*bc03sc*i*
alias: pci:v00008086d0000160Asv*sd*bc03sc*i*
alias: pci:v00008086d0000161Esv*sd*bc03sc*i*
alias: pci:v00008086d0000161Bsv*sd*bc03sc*i*
alias: pci:v00008086d00001616sv*sd*bc03sc*i*
alias: pci:v00008086d00001612sv*sd*bc03sc*i*
alias: pci:v00008086d0000160Esv*sd*bc03sc*i*
alias: pci:v00008086d0000160Bsv*sd*bc03sc*i*
alias: pci:v00008086d00001606sv*sd*bc03sc*i*
alias: pci:v00008086d00001602sv*sd*bc03sc*i*
alias: pci:v00008086d00000155sv*sd*bc03sc*i*
alias: pci:v00008086d00000157sv*sd*bc03sc*i*
alias: pci:v00008086d00000F33sv*sd*bc03sc*i*
alias: pci:v00008086d00000F32sv*sd*bc03sc*i*
alias: pci:v00008086d00000F31sv*sd*bc03sc*i*
alias: pci:v00008086d00000F30sv*sd*bc03sc*i*
alias: pci:v00008086d00000D26sv*sd*bc03sc*i*
alias: pci:v00008086d00000D16sv*sd*bc03sc*i*
alias: pci:v00008086d00000D06sv*sd*bc03sc*i*
alias: pci:v00008086d00000A2Esv*sd*bc03sc*i*
alias: pci:v00008086d00000A1Esv*sd*bc03sc*i*
alias: pci:v00008086d00000A0Esv*sd*bc03sc*i*
alias: pci:v00008086d00000A26sv*sd*bc03sc*i*
alias: pci:v00008086d00000A16sv*sd*bc03sc*i*
alias: pci:v00008086d00000A06sv*sd*bc03sc*i*
alias: pci:v00008086d00000C26sv*sd*bc03sc*i*
alias: pci:v00008086d00000C16sv*sd*bc03sc*i*
alias: pci:v00008086d00000C06sv*sd*bc03sc*i*
alias: pci:v00008086d00000426sv*sd*bc03sc*i*
alias: pci:v00008086d00000416sv*sd*bc03sc*i*
alias: pci:v00008086d00000406sv*sd*bc03sc*i*
alias: pci:v00008086d00000D2Esv*sd*bc03sc*i*
alias: pci:v00008086d00000D1Esv*sd*bc03sc*i*
alias: pci:v00008086d00000D0Esv*sd*bc03sc*i*
alias: pci:v00008086d00000D2Bsv*sd*bc03sc*i*
alias: pci:v00008086d00000D1Bsv*sd*bc03sc*i*
alias: pci:v00008086d00000D0Bsv*sd*bc03sc*i*
alias: pci:v00008086d00000D2Asv*sd*bc03sc*i*
alias: pci:v00008086d00000D1Asv*sd*bc03sc*i*
alias: pci:v00008086d00000D0Asv*sd*bc03sc*i*
alias: pci:v00008086d00000D22sv*sd*bc03sc*i*
alias: pci:v00008086d00000D12sv*sd*bc03sc*i*
alias: pci:v00008086d00000D02sv*sd*bc03sc*i*
alias: pci:v00008086d00000A2Bsv*sd*bc03sc*i*
alias: pci:v00008086d00000A1Bsv*sd*bc03sc*i*
alias: pci:v00008086d00000A0Bsv*sd*bc03sc*i*
alias: pci:v00008086d00000A2Asv*sd*bc03sc*i*
alias: pci:v00008086d00000A1Asv*sd*bc03sc*i*
alias: pci:v00008086d00000A0Asv*sd*bc03sc*i*
alias: pci:v00008086d00000A22sv*sd*bc03sc*i*
alias: pci:v00008086d00000A12sv*sd*bc03sc*i*
alias: pci:v00008086d00000A02sv*sd*bc03sc*i*
alias: pci:v00008086d00000C2Esv*sd*bc03sc*i*
alias: pci:v00008086d00000C1Esv*sd*bc03sc*i*
alias: pci:v00008086d00000C0Esv*sd*bc03sc*i*
alias: pci:v00008086d00000C2Bsv*sd*bc03sc*i*
alias: pci:v00008086d00000C1Bsv*sd*bc03sc*i*
alias: pci:v00008086d00000C0Bsv*sd*bc03sc*i*
alias: pci:v00008086d00000C2Asv*sd*bc03sc*i*
alias: pci:v00008086d00000C1Asv*sd*bc03sc*i*
alias: pci:v00008086d00000C0Asv*sd*bc03sc*i*
alias: pci:v00008086d00000C22sv*sd*bc03sc*i*
alias: pci:v00008086d00000C12sv*sd*bc03sc*i*
alias: pci:v00008086d00000C02sv*sd*bc03sc*i*
alias: pci:v00008086d0000042Esv*sd*bc03sc*i*
alias: pci:v00008086d0000041Esv*sd*bc03sc*i*
alias: pci:v00008086d0000040Esv*sd*bc03sc*i*
alias: pci:v00008086d0000042Bsv*sd*bc03sc*i*
alias: pci:v00008086d0000041Bsv*sd*bc03sc*i*
alias: pci:v00008086d0000040Bsv*sd*bc03sc*i*
alias: pci:v00008086d0000042Asv*sd*bc03sc*i*
alias: pci:v00008086d0000041Asv*sd*bc03sc*i*
alias: pci:v00008086d0000040Asv*sd*bc03sc*i*
alias: pci:v00008086d00000422sv*sd*bc03sc*i*
alias: pci:v00008086d00000412sv*sd*bc03sc*i*
alias: pci:v00008086d00000402sv*sd*bc03sc*i*
alias: pci:v00008086d0000016Asv*sd*bc03sc*i*
alias: pci:v00008086d0000015Asv*sd*bc03sc*i*
alias: pci:v00008086d00000162sv*sd*bc03sc*i*
alias: pci:v00008086d00000152sv*sd*bc03sc*i*
alias: pci:v00008086d00000166sv*sd*bc03sc*i*
alias: pci:v00008086d00000156sv*sd*bc03sc*i*
alias: pci:v00008086d0000016Asv0000152Dsd00008990bc03sc*i*
alias: pci:v00008086d00000126sv*sd*bc03sc*i*
alias: pci:v00008086d00000116sv*sd*bc03sc*i*
alias: pci:v00008086d00000106sv*sd*bc03sc*i*
alias: pci:v00008086d0000010Asv*sd*bc03sc*i*
alias: pci:v00008086d00000122sv*sd*bc03sc*i*
alias: pci:v00008086d00000112sv*sd*bc03sc*i*
alias: pci:v00008086d00000102sv*sd*bc03sc*i*
alias: pci:v00008086d00000046sv*sd*bc03sc*i*
alias: pci:v00008086d00000042sv*sd*bc03sc*i*
alias: pci:v00008086d0000A011sv*sd*bc03sc*i*
alias: pci:v00008086d0000A001sv*sd*bc03sc*i*
alias: pci:v00008086d00002E92sv*sd*bc03sc*i*
alias: pci:v00008086d00002E42sv*sd*bc03sc*i*
alias: pci:v00008086d00002E32sv*sd*bc03sc*i*
alias: pci:v00008086d00002E22sv*sd*bc03sc*i*
alias: pci:v00008086d00002E12sv*sd*bc03sc*i*
alias: pci:v00008086d00002E02sv*sd*bc03sc*i*
alias: pci:v00008086d00002A42sv*sd*bc03sc*i*
alias: pci:v00008086d00002A12sv*sd*bc03sc*i*
alias: pci:v00008086d00002A02sv*sd*bc03sc*i*
alias: pci:v00008086d000029D2sv*sd*bc03sc*i*
alias: pci:v00008086d000029C2sv*sd*bc03sc*i*
alias: pci:v00008086d000029B2sv*sd*bc03sc*i*
alias: pci:v00008086d000029A2sv*sd*bc03sc*i*
alias: pci:v00008086d00002992sv*sd*bc03sc*i*
alias: pci:v00008086d00002982sv*sd*bc03sc*i*
alias: pci:v00008086d00002972sv*sd*bc03sc*i*
alias: pci:v00008086d000027AEsv*sd*bc03sc*i*
alias: pci:v00008086d000027A2sv*sd*bc03sc*i*
alias: pci:v00008086d00002772sv*sd*bc03sc*i*
alias: pci:v00008086d00002592sv*sd*bc03sc*i*
alias: pci:v00008086d0000258Asv*sd*bc03sc*i*
alias: pci:v00008086d00002582sv*sd*bc03sc*i*
alias: pci:v00008086d00002572sv*sd*bc03sc*i*
alias: pci:v00008086d0000358Esv*sd*bc03sc*i*
alias: pci:v00008086d00003582sv*sd*bc03sc*i*
alias: pci:v00008086d00002562sv*sd*bc03sc*i*
alias: pci:v00008086d00003577sv*sd*bc03sc*i*
depends: drm_kms_helper,drm,video,i2c-algo-bit
intree: Y
vermagic: 3.16.0-24-generic SMP mod_unload modversions
signer: Magrathea: Glacier signing key
sig_key: 3C:88:40:D1:7B:DF:90:2E:17:1E:23:B4:BB:C2:72:8E:B6:94:C7:0A
sig_hashalgo: sha512
parm: modeset:Use kernel modesetting [KMS] (0=DRM_I915_KMS from .config, 1=on, -1=force vga console preference [default]) (int)
parm: panel_ignore_lid:Override lid status (0=autodetect, 1=autodetect disabled [default], -1=force lid closed, -2=force lid open) (int)
parm: powersave:Enable powersavings, fbc, downclocking, etc. (default: true) (int)
parm: semaphores:Use semaphores for inter-ring sync (default: -1 (use per-chip defaults)) (int)
parm: enable_rc6:Enable power-saving render C-state 6. Different stages can be selected via bitmask values (0 = disable; 1 = enable rc6; 2 = enable deep rc6; 4 = enable deepest rc6). For example, 3 would enable rc6 and deep rc6, and 7 would enable everything. default: -1 (use per-chip default) (int)
parm: enable_fbc:Enable frame buffer compression for power savings (default: -1 (use per-chip default)) (int)
parm: lvds_downclock:Use panel (LVDS/eDP) downclocking for power savings (default: false) (int)
parm: lvds_channel_mode:Specify LVDS channel mode (0=probe BIOS [default], 1=single-channel, 2=dual-channel) (int)
parm: lvds_use_ssc:Use Spread Spectrum Clock with panels [LVDS/eDP] (default: auto from VBT) (int)
parm: vbt_sdvo_panel_type:Override/Ignore selection of SDVO panel mode in the VBT (-2=ignore, -1=auto [default], index in VBT BIOS table) (int)
parm: reset:Attempt GPU resets (default: true) (bool)
parm: enable_hangcheck:Periodically check GPU activity for detecting hangs. WARNING: Disabling this can cause system wide hangs. (default: true) (bool)
parm: enable_ppgtt:Override PPGTT usage. (-1=auto [default], 0=disabled, 1=aliasing, 2=full) (int)
parm: enable_psr:Enable PSR (default: false) (int)
parm: preliminary_hw_support:Enable preliminary hardware support. (int)
parm: disable_power_well:Disable the power well when possible (default: true) (int)
parm: enable_ips:Enable IPS (default: true) (int)
parm: fastboot:Try to skip unnecessary mode sets at boot time (default: false) (bool)
parm: prefault_disable:Disable page prefaulting for pread/pwrite/reloc (default:false). For developers only. (bool)
parm: invert_brightness:Invert backlight brightness (-1 force normal, 0 machine defaults, 1 force inversion), please report PCI device ID, subsystem vendor and subsystem device ID to [email protected], if your machine needs it. It will then be included in an upcoming module version. (int)
parm: disable_display:Disable display (default: false) (bool)
parm: disable_vtd_wa:Disable all VT-d workarounds (default: false) (bool)
parm: enable_cmd_parser:Enable command parsing (1=enabled [default], 0=disabled) (int)
lshw -C Display,lsmodandmodinfo i915.