Tried two different devices (WinTV2 USB and Elgato USB). Both exhibit the same messages in dmesg.
[ 227.226707] cx231xx 1-5:1.1: New device Elgato Video Capture @ 480 Mbps (0fd9:0037) with 6 interfaces
[ 227.229682] cx231xx 1-5:1.1: Identified as Elgato Video Capture V2 (card=16)
[ 227.232758] i2c i2c-15: Added multiplexed i2c bus 17
[ 227.232775] i2c i2c-15: Added multiplexed i2c bus 18
[ 227.457709] cx25840 14-0044: cx23102 A/V decoder found @ 0x88 (cx231xx #0-0)
[ 232.261259] cx25840 14-0044: loaded v4l-cx231xx-avcore-01.fw firmware (16382 bytes)
[ 232.447285] cx231xx 1-5:1.1: v4l2 driver version 0.0.3
[ 232.857541] cx231xx 1-5:1.1: Registered video device video0 [v4l2]
[ 232.857590] cx231xx 1-5:1.1: Registered VBI device vbi0
[ 232.857850] cx231xx 1-5:1.1: audio EndPoint Addr 0x83, Alternate settings: 3
[ 232.857853] cx231xx 1-5:1.1: video EndPoint Addr 0x84, Alternate settings: 5
[ 232.857855] cx231xx 1-5:1.1: VBI EndPoint Addr 0x85, Alternate settings: 2
[ 232.857857] cx231xx 1-5:1.1: sliced CC EndPoint Addr 0x86, Alternate settings: 2
[ 232.857860] usb 1-5: couldn't get decoder output pad for V4L I/O
[ 232.857862] cx231xx 1-5:1.1: V4L2 device vbi0 deregistered
[ 232.857900] cx231xx 1-5:1.1: V4L2 device video0 deregistered
[ 232.858025] cx231xx: probe of 1-5:1.1 failed with error -22
