Comment 4 for bug 458444

(copy-paste from the earlier duplicate)
Confirming this.

The distributed firmware currently at /lib/firmware/dvb-usb-af9015.fw is an old buggy version.

[ 12.559817] dvb-usb: downloading firmware from file 'dvb-usb-af9015.fw'
[ 13.327234] af9013: firmware version:4.65.0
[ 14.083895] af9013: firmware version:4.65.0

This version is known to not work at all with some dual tuner af9013 devices, and the current firmware used for these devices is version 4.95.0.

To fix, the new firmware has to be installed. The device must be removed from usb, ideally plugged into another computer to have it's firmware purged, and then replugged. If the device is detected in a 'warm state' the new firmware will not be loaded, and you'll need unplug it again, and try leaving it disconnected for a longish time.

Firmware 4.65.0 should be replaced with the above attached 4.95.0