mjhjmtu

usually I use the laptop to hear music at home while doing things off the computer. As it is supposed, after some time of inactivity the screen saver starts on my debian (stretch) system.

To change the volume of music I have to reenter my user password to login, because at the login screen the volume hotkeys are dead, while the screen brightness hotkeys are still working. This behaviour may be superb at partys to prevent guests from manipulating the volume - but everytime I get a phone call I have to reenter the whole password just to have the permission to mute/unmute the music.

I spent some time at the internet figuring out how to add permissions to the volume hotkeys to be working at login screen like the screen brightness hotkeys. I have not found any hint.
So, what do I have to do? :)

Thanks!

edit: Its a "stock" Debian Stretch installation on a Thinkpad T400, except for using Gnome Classic mode as user interface. Sorry, I am not an advanced user, so if any additional information needed, please specify and I will deliver :)

[output of uname -a]
Linux debian 4.9.0-6-amd64 #1 SMP Debian 4.9.88-1+deb9u1 (2018-05-07) x86_64 GNU/Linux

[excerpt of hwinfo]
 description: Notebook
 product: 6474D88
 vendor: LENOVO
 version: ThinkPad T400
 serial: 
 width: 64 bits
 capabilities: smbios-2.4 dmi-2.4 smp vsyscall32
 configuration: administrator_password=disabled boot=normal chassis=notebook family=ThinkPad T400 frontpanel_password=unknown keyboard_password=disabled power-on_password=disabled

*-multimedia
 description: Audio device
 product: 82801I (ICH9 Family) HD Audio Controller
 vendor: Intel Corporation
 physical id: 1b
 bus info: pci@0000:00:1b.0
 version: 03
 width: 64 bits
 clock: 33MHz
 capabilities: pm msi pciexpress bus_master cap_list
 configuration: driver=snd_hda_intel latency=0
 resources: irq:33 memory:fc120000-fc123fff


[output of modinfo]
Module Size Used by
option 53248 0
uas 24576 0
usb_wwan 20480 1 option
qmi_wwan 28672 0
usbserial 49152 2 option,usb_wwan
usb_storage 73728 1 uas
cdc_wdm 20480 1 qmi_wwan
usbnet 45056 1 qmi_wwan
mii 16384 1 usbnet
fuse 98304 3
ctr 16384 2
ccm 20480 1
rfcomm 77824 2
bnep 20480 2
binfmt_misc 20480 1
uvcvideo 90112 0
videobuf2_vmalloc 16384 1 uvcvideo
videobuf2_memops 16384 1 videobuf2_vmalloc
videobuf2_v4l2 24576 1 uvcvideo
videobuf2_core 40960 2 uvcvideo,videobuf2_v4l2
videodev 176128 3 uvcvideo,videobuf2_core,videobuf2_v4l2
media 40960 2 uvcvideo,videodev
coretemp 16384 0
arc4 16384 2
iwldvm 139264 0
mac80211 671744 1 iwldvm
iTCO_wdt 16384 0
kvm 593920 0
iTCO_vendor_support 16384 1 iTCO_wdt
pcmcia 65536 0
irqbypass 16384 1 kvm
r852 20480 0
sm_common 16384 1 r852
nand 61440 2 r852,sm_common
nand_ecc 16384 1 nand
nand_bch 16384 1 nand
pcspkr 16384 0
bch 24576 1 nand_bch
r592 20480 0
evdev 24576 14
nand_ids 16384 1 nand
memstick 20480 1 r592
joydev 20480 0
mtd 65536 3 nand_bch,sm_common,nand
btusb 45056 0
iwlwifi 151552 1 iwldvm
yenta_socket 49152 0
i915 1257472 12
pcmcia_rsrc 20480 1 yenta_socket
pcmcia_core 24576 3 yenta_socket,pcmcia,pcmcia_rsrc
btrtl 16384 1 btusb
btbcm 16384 1 btusb
btintel 16384 1 btusb
cfg80211 589824 3 iwlwifi,mac80211,iwldvm
bluetooth 552960 31 btrtl,btintel,bnep,btbcm,rfcomm,btusb
snd_hda_codec_conexant 24576 1
snd_hda_codec_generic 69632 1 snd_hda_codec_conexant
sg 32768 0
lpc_ich 24576 0
mfd_core 16384 1 lpc_ich
serio_raw 16384 0
drm_kms_helper 155648 1 i915
snd_hda_intel 36864 8
drm 360448 10 i915,drm_kms_helper
snd_hda_codec 135168 3 snd_hda_intel,snd_hda_codec_conexant,snd_hda_codec_generic
shpchp 36864 0
i2c_algo_bit 16384 1 i915
snd_hda_core 86016 4 snd_hda_intel,snd_hda_codec_conexant,snd_hda_codec,snd_hda_codec_generic
mei_me 36864 0
mei 102400 1 mei_me
snd_hwdep 16384 1 snd_hda_codec
snd_pcm 110592 4 snd_hda_intel,snd_hda_codec,snd_hda_core
snd_timer 32768 1 snd_pcm
thinkpad_acpi 86016 0
nvram 16384 1 thinkpad_acpi
snd 86016 23 snd_hda_intel,snd_hwdep,snd_hda_codec_conexant,snd_hda_codec,snd_timer,thinkpad_acpi,snd_hda_codec_generic,snd_pcm
soundcore 16384 1 snd
rfkill 24576 7 bluetooth,thinkpad_acpi,cfg80211
wmi 16384 0
ac 16384 0
battery 20480 0
button 16384 1 i915
video 40960 2 thinkpad_acpi,i915
acpi_cpufreq 20480 1
parport_pc 28672 1
ppdev 20480 0
lp 20480 0
parport 49152 3 lp,parport_pc,ppdev
ip_tables 24576 0
x_tables 36864 1 ip_tables
autofs4 40960 2
ext4 585728 2
crc16 16384 2 bluetooth,ext4
jbd2 106496 1 ext4
crc32c_generic 16384 2
fscrypto 28672 1 ext4
ecb 16384 0
lrw 16384 0
glue_helper 16384 0
ablk_helper 16384 0
cryptd 24576 1 ablk_helper
aes_x86_64 20480 3
mbcache 16384 3 ext4
xts 16384 3
gf128mul 16384 2 lrw,xts
algif_skcipher 20480 0
af_alg 16384 1 algif_skcipher
dm_crypt 28672 1
dm_mod 118784 9 dm_crypt
sd_mod 49152 3
psmouse 135168 0
ahci 36864 2
libahci 32768 1 ahci
i2c_i801 24576 0
libata 249856 2 ahci,libahci
i2c_smbus 16384 1 i2c_i801
scsi_mod 225280 5 sd_mod,usb_storage,libata,uas,sg
firewire_ohci 40960 0
sdhci_pci 28672 0
sdhci 45056 1 sdhci_pci
mmc_core 147456 2 sdhci,sdhci_pci
firewire_core 65536 1 firewire_ohci
crc_itu_t 16384 1 firewire_core
xhci_pci 16384 0
xhci_hcd 188416 1 xhci_pci
ehci_pci 16384 0
thermal 20480 0
uhci_hcd 45056 0
ehci_hcd 81920 1 ehci_pci
e1000e 249856 0
usbcore 253952 15 usbnet,uvcvideo,usb_storage,ehci_hcd,qmi_wwan,uhci_hcd,cdc_wdm,usbserial,xhci_pci,btusb,option,uas,usb_wwan,xhci_hcd,ehci_pci
ptp 20480 1 e1000e
pps_core 16384 1 ptp
usb_common 16384 1 usbcore