[linux-dvb] [mythtv-users] will Nova-T 500 work?

Janne Grunau janne-mythtvusers at grunau.be
Mon Jun 25 15:06:16 CEST 2007


On Monday 25 June 2007 08:24:45 Eduard Huguet wrote:
> > ---------- Missatge reenviat ----------
> > From: Matt Doran <matt.doran at papercut.biz>
> > To: Discussion about mythtv <mythtv-users at mythtv.org>
> > Date: Mon, 25 Jun 2007 10:48:15 +1000
> > Subject: Re: [mythtv-users] will Nova-T 500 work?
> >
> > David Campbell wrote:
> > > Henrik Beckman wrote:
> > >> On the pre hotplug driver i was, 'Hauppauge Nova-T 500 Dual
> > >> DVB-T successfully deinitialized and disconnected' and then
> > >> after a while you got an oops.
> > >>
> > >> On the newer hotplug drivers you get an write failed for mt2060
> > >> error message, I don´t have the exact message at hand right now.
> > >
> > > <apologies in advance for the bumping of the old thread>
> > >
> > > I am running Kubuntu with their own 2.6.20-15 kernel on my system
> > > with EIT and I am seeing the dreaded errors in messages and the
> > > card just refuses to tune.
> > >
> > > Jun 19 02:56:56 kubuntu kernel: [126723.015463] usb 4-1: USB
> > > disconnect, address 3
> > > Jun 19 02:56:56 kubuntu kernel: [126723.021150] mt2060 I2C write
> > > failed Jun 19 02:56:56 kubuntu kernel: [126723.021495] mt2060 I2C
> > > write failed
> > >
> > > Does anyone have any advice on making the system more stable?  My
> > > own kernel?  Stop using EIT?
> >
> > Stop using EIT.
>
> Also you could effectively try to upgrade your kernel, as it seems
> that the problem is closesly related to the USB layout. As a
> recommendation, you should also disable the DVB layout in kernel
> options and use lastest HG drivers from LinuxTV.
>
> I'm currently using Sabayon 3.3 (Gentoo) + 2.6.21-r3 + HG drivers
> with my Nova-T 500 and the disconnect problem is really sporadic
> (also I have EIT on, as I rely solely on it to retrieve program
> listings).

But you still see disconnects? I haven't seen any in the last weeks and 
I actually don't remember when I saw the last one. Logs aren't 
available due to a hd failure.

I do remember that I haven't seen a disconnect since mid may. I'm using 
2.6.21.* and v4l-dvb hg from the same time.
The error occured only sporadic here even with mythtv's eit scanning 
enabled. But more than a month with two reboot and 24/7 running 
mythbackend is a new record (previous record was 11 days).

It's hard to say after which it's safe to assume that the bug is fixed 
especially since I have no hard statistics.
 But let's us assume normal distributed values with mean = 5 days and 
variance = 2 (which are optimistic guesses. more realistic values are 
mean = 3 days and standard deviation = 2 days).

The p-value for seeing one month (31 days) without without usb 
disconnent is 4.490409e-11. I doubt anyone will claim that that is not 
significant. I.e. it is very highly unlikely that the disconnects have 
still the same occurance pattern.
There is a minor drawback, if the disconnects depend on the time since 
the last reboot it's not over 31 days but just 17 p-value decreases to 
0.00151. Still significant to the 1% level.

Janne



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