I just posted about this in mythtv-users but it fits here too...

I've been successfully using this device in Myth/SL6 for many months, 
but had to use kernel-lt from elrepo to get support.  This broke briefly 
last December on going from 3.10.21-1 to 3.10.22-1

https://bugzilla.kernel.org/show_bug.cgi?id=66861

I see the same bug with the el7 stock kernel, 3.10.0-123.9.2; according 
to dmesg it's fixed with kernel-ml from elrepo, which I now have 
installed.  It sounds more cutting-edge than I would really like...

uname -r   3.17.2-1.el7.elrepo.x86_64

John P