Unless your distro patched support into the kernel you need at least 3.16
Booting first then plugging the 292e will make the interesting messages appear at the end of the dmesg output.
I just booted my not yet in service box and plugged the stick and it looked like -
[ 339.969501] usb 1-1.2: new high-speed USB device number 5 using xhci_hcd
[ 340.065518] usb 1-1.2: New USB device found, idVendor=2013, idProduct=025f
[ 340.068736] usb 1-1.2: New USB device strings: Mfr=3, Product=1, SerialNumber=2
[ 340.071870] usb 1-1.2: Product: PCTV 292e
[ 340.074910] usb 1-1.2: Manufacturer: PCTV
[ 340.077897] usb 1-1.2: SerialNumber: 0011403948
[ 340.128630] Linux video capture interface: v2.00
[ 340.155816] em28xx: New device PCTV PCTV 292e @ 480 Mbps (2013:025f, interface 0, class 0)
[ 340.158670] em28xx: DVB interface 0 found: isoc
[ 340.161702] em28xx: chip ID is em28178
[ 342.103036] em28178 #0: EEPROM ID = 26 00 01 00, EEPROM hash = 0xc70efd04
[ 342.105843] em28178 #0: EEPROM info:
[ 342.108526] em28178 #0: microcode start address = 0x0004, boot configuration = 0x01
[ 342.120724] em28178 #0: AC97 audio (5 sample rates)
[ 342.123425] em28178 #0: 500mA max power
[ 342.126017] em28178 #0: Table at offset 0x27, strings=0x146a, 0x1888, 0x0a7e
[ 342.128701] em28178 #0: Identified as PCTV tripleStick (292e) (card=94)
[ 342.131204] em28178 #0: dvb set to isoc mode.
[ 342.133675] usbcore: registered new interface driver em28xx
[ 342.151525] em28178 #0: Binding DVB extension
[ 342.163797] i2c i2c-9: Added multiplexed i2c bus 10
[ 342.166226] si2168 9-0064: si2168: Silicon Labs Si2168 successfully attached
[ 342.173004] si2157 10-0060: si2157: Silicon Labs Si2157 successfully attached
[ 342.175608] DVB: registering new adapter (em28178 #0)
[ 342.178171] usb 1-1.2: DVB: registering adapter 0 frontend 0 (Silicon Labs Si2168)...
[ 342.181732] em28178 #0: DVB extension successfully initialized
[ 342.184026] em28xx: Registered (Em28xx dvb Extension) extension
I don't think that this guarantees working yet as when something actually tries to use it, the f/w loads.
This bit may look different for you as IIRC I renamed a file to make it work first time (Memory failing but I think it did work without that - but logged a failed load, then tried something else).
Start tvh ....
[ 960.564615] si2168 9-0064: si2168: found a 'Silicon Labs Si2168' in cold state
[ 960.580388] si2168 9-0064: si2168: downloading firmware from file 'dvb-demod-si2168-02.fw'
[ 960.752894] si2168 9-0064: si2168: found a 'Silicon Labs Si2168' in warm state
[ 960.752930] usb 1-1.2: DVB: adapter 0 frontend 0 frequency 0 out of range (110000000..862000000)
Then in tvh config it shows as Silicon Labs Si2168
I didn't go any further with tvh yet as where the box is currently it doesn't have an RF feed.
As for the firmwares just for the record here's what I have - you can see I just copied one of them to a different name - though given my 292e isn't actually in use yet I can't say how good an idea this was :-) and it was October when I did it, so I don't know what's about or what it's called now.
md5sum /lib/firmware/dvb-demod-si2168-*
87c317e0b75ad49c2f2cbf35572a8093 /lib/firmware/dvb-demod-si2168-01.fw
d8da7ff67cd56cd8aa4e101aea45e052 /lib/firmware/dvb-demod-si2168-02.fw
d8da7ff67cd56cd8aa4e101aea45e052 /lib/firmware/dvb-demod-si2168-b40-01.fw