[linux-dvb] Nova-T 500 issues - losing one tuner

Philip Pemberton lists at philpem.me.uk
Tue Feb 26 20:18:52 CET 2008

Patrik Hansson wrote:
> Just wanted to say that I´m experiencing the same.
> Using latest rev (the one with patches merged) + unknown remote key patch.
> Ubuntu 7.10
> Also having a lot of "prebuffer timeout 10 times" i the middle of shows.

I think I might have a workaround... On Mythbuntu or one of the many Ubuntu 
variants, this seems to work:

1)  Run:
       lsmod |grep usbcore

2)  If step 1 produced any output that started with 'usbcore', then usbcore is 
loaded as a module. Perform step 3a. Otherwise, step 3b.

3a) Create a text file called /etc/modprobe.d/local-dvb (the name is fairly 
irrelevant). Insert one line of text into it:
       options usbcore autosuspend=-1
     Now go to step 4.

3b) Your kernel has usbcore built in. That means you have to modify the kernel 
command line...
     Edit /boot/grub/menu.lst (you'll need to sudo to do this). Search for 
this line:
# defoptions=quiet splash
     Amend it to read:
# defoptions=quiet splash usbcore.autosuspend=-1
     It's meant to be commented out, so leave the hash at the beginning of the 
line alone... Save and exit, then run ...
sudo update grub
     Ubuntu will regenerate grub.conf, using the new kernel command line. Off 
to step 4 you go!

     If you're using a non-Debian distro (e.g. Fedora), do the same thing but 
edit the 'kernel' line instead. It might read:
kernel          /boot/vmlinuz-2.6.24-8-generic root=LABEL=/ ro quiet splash
     Change it to:
kernel          /boot/vmlinuz-2.6.24-8-generic root=LABEL=/ ro quiet splash 

4)  Reboot your PC.

This is a bit long-winded, but saves a kernel recompile, and a ton of messing 
around recompiling kernels when Ubuntu do another release.

I'm working on what I consider to be a better fix, which involves using the 
kernel's Quirks function to disable USB suspend just for the DiBcom 
controllers. That is, the kernel won't try and suspend them at all...

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