Hi,
i try without succeded to use an DVB tuner RTL2838
lsusb
Bus 001 Device 006: ID 0bda:2838 Realtek Semiconductor Corp. RTL2838 DVB-T
lsmod|grep rtl
rtl2832 13564 1
i2c_mux 3163 1 rtl2832
dvb_usb_rtl28xxu 23670 1
dvb_usb_v2 17404 1 dvb_usb_rtl28xxu
dvb_core 104949 2 rtl2832,dvb_usb_v2
rc_core 25853 14 ir_sharp_decoder,ir_xmp_decoder,lirc_dev,ir_lirc_codec,dvb_usb_rtl28xxu,ir_rc5_decoder,ir_nec_decoder,ir_sony_decoder,ir_mce_kbd_decoder,ir_jvc_decoder,dvb_usb_v2,ir_rc6_decoder,ir_sanyo_decoder
it seems to be an Vid 0x0bda & pid 0x02838
with
uname -r
4.2.3-2-osmc
Here is dmesg
[ 2.361216] usb 1-1.5.1: new high-speed USB device number 5 using dwc_otg
[ 2.472970] usb 1-1.5.1: New USB device found, idVendor=0bda, idProduct=2838
[ 2.472992] usb 1-1.5.1: New USB device strings: Mfr=1, Product=2, SerialNumb er=3
[ 2.473003] usb 1-1.5.1: Product: RTL2838UHIDIR
[ 2.473016] usb 1-1.5.1: Manufacturer: Realtek
[ 2.473026] usb 1-1.5.1: SerialNumber: 00000001
[ 4.104011] usb 1-1.5.1: dvb_usb_v2: found a 'Realtek RTL2832U reference desi gn' in warm state
[ 4.143163] dvb_usb_rtl28xxu: probe of 1-1.5.1:1.0 failed with error -32
[ 4.144185] usbcore: registered new interface driver dvb_usb_rtl28xxu
[ 75.162611] usb 1-1.5.1: USB disconnect, device number 5
[ 79.171814] usb 1-1.5.1: new high-speed USB device number 6 using dwc_otg
[ 79.283714] usb 1-1.5.1: New USB device found, idVendor=0bda, idProduct=2838
[ 79.283738] usb 1-1.5.1: New USB device strings: Mfr=1, Product=2, SerialNumb er=3
I wonder what is > probe of 1-1.5.1:1.0 failed with error -32
tvheadend 4.0.5 see the device but won’t scan anything. I try with w_scan & scan … nothing 
. Everything work fine on windows with signal above 80%.
Two times, and i don’t know why, scan find the channels. I notice when i reboot raspbery, lsusb show the tuner but i didn’t see any device in tvheadend.
the raspberry is on 2A power supply, and i try to plug the device directly on rapberry or on self powered hub.
Thanks for your help.