kiki@kiki:~$ cat /etc/apt/sources.list
#/etc/apt/sources.list
#deb
http://deb.debian.org/debian/ stretch main contrib non-free
#deb
http://security.debian.org/ stretch/updates main contrib non-free
#deb
http://deb.debian.org/debian/ stretch-updates main contrib non-free
kiki@kiki:~$ lsmod | grep ath
ath3k 24576 0
ath9k 143360 0
ath9k_common 24576 1 ath9k
ath9k_hw 512000 2 ath9k_common,ath9k
ath 36864 3 ath9k_common,ath9k,ath9k_hw
mac80211 1175552 1 ath9k
bluetooth 958464 37 btrtl,btmtk,btintel,btbcm,bnep,ath3k,btusb,rfcomm
cfg80211 1146880 4 ath9k_common,ath9k,ath,mac80211
rfkill 36864 6 ath9k,asus_wmi,bluetooth,cfg80211
usbcore 348160 11 xhci_hcd,ehci_pci,usbnet,usbhid,rndis_host,uvcvideo,ehci_hcd,ath3k,btusb,xhci_pci,cdc_ether
kiki@kiki:~$ dmesg | grep firmware
[ 0.070165] Spectre V2 : Enabling Restricted Speculation for firmware calls
[ 1.790012] psmouse serio4: elantech: assuming hardware version 4 (with firmware version 0x460f04)
[ 5.542702] platform regulatory.0: firmware: direct-loading firmware regulatory.db
[ 5.542909] platform regulatory.0: firmware: direct-loading firmware regulatory.db.p7s
[ 5.799750] usb 2-5: firmware: direct-loading firmware ar3k/AthrBT_0x11020000.dfu
[ 5.833310] usb 2-5: firmware: direct-loading firmware ar3k/ramps_0x11020000_40.dfu
kiki@kiki:~$