DVB-T USB Permission Denied - Fedora Core

I've got a FreeCom DVB-T USB 2.0 freeview stick. To get it to work under FC5 just drop the two firmware files into the /lib/firmware directory and plug it in.



Install Kaffeine to watch TV pritty much instantly (the channels > scan for channels option on the DVB menu takes care of the tzap-esq work which usually needs to be done manually).

One problem you might run into is Kaffeine (or any other prog) sating it either can't find the device or you don;t have permissions to acces it.

Two things could becausing the problem.

1. You've got a problem with your install
   
2. The permissions on the /dev/dvb/adapter are opreventing you from using the device.
   

I'm not going into the first issue in this article as the causes could be endless, sufice to say that if you have a fresh FC5 install and have copied the to firmware files (dvb-usb-wt220u-01.fw dvb-usb-wt220u-02.f) into the /lib/firmware/ folder it should work. It does for me!

The second issue is more common. First off find out if it is a permissions issue by trying to access the device as root.

• Open a command prompt and type in SU, you should be prompted for a password. This is the root password and you should know this unless someone else has setup the system (in which case ask them).
• Now run kaffeine by running the following in a shell

[root@localhost /]# kaffeine&

• The Kaffeine window should now appear and you should see the DVB option available in the bottom right.

• Before you clikc this icon goto the DVB menu at the top of the screen and select channels from it. This shiould come up with another screen with a button at the top which says scan.
  
• Above the scan button is a drop down entitles 'scan on' , this is suppose to be set to your nearest tansmitter, for me it's waltham (covers a lot of the midlands - uk). Pick the one you thinks closest. Once you've done that it scan and you should start to see the channels appear ont he right hand side. Once it's finished, highlight all the channels you want and click ont he 'add selected' button to transfer them into your 'play list'.
• O.K all the way out and you should now have a list of channels on the left hand side which you can double click to watch. Give it a go!

Once you've done this and have watched a bit of telly (maybe a bit jittery but TV nether he less) you now need to go about changing the permissions on the /dev files so that everyone can use it (not just root).

Because the device files a re created dynamically by udev when the usb device is attached, you can't just chmod -R 777 /dev/dvb/adapter0/ . If you do, when the computer comes up next ro when you detach and reattach the device, the file permissions on the device files will reset to their original. Instead what we have to do is edit the /etc/udev/rules.d/50-udev.rules file.

This file covers a host of diffrent devices you might want to attach to your compuetr and have hot-mounted . It governs where device files are created and with whayt permissions. The lines we need to edit are percursed with the #DVB title. Crack open you fav editor as root and edit the 50-udev.rules file. The #DVB sectio is about half way down, heres what mine use to look like (line numbers in bold).

1: DVB
2: KERNEL=="dvb", MODE="0660"
3: SUBSYSTEM=="dvb", PROGRAM="/bin/sh -c 'K=%k; K=$${K#dvb}; printf dvb/adapter%%i/%%s $${K%%%%.*} $${K#*.}'", 4: NAME="%c", MODE="0660"

As you can probably see from the mode operands, the permission octets are set to 0660. This is the problem. simply change the mode to 0777 or something suitable and save the file. Here's my funstional 50-udev.rules file,

1: # DVB
2: KERNEL=="dvb", MODE="0777"
3: SUBSYSTEM=="dvb", PROGRAM="/bin/sh -c 'K=%k; K=$${K#dvb}; printf dvb/adapter%%i/%%s $${K%%%%.*} $${K#*.}'", 4: NAME="%c", MODE="0777"

Like I said, this works for me and, given the fairly vanilla state of my box, should work for anyone with a FC5 install.