[mythtvnz] Second USB DVB-T tuner causes high load

[Steven Ellis]

On Thu, October 8, 2009 9:36 pm, Dylan Hall wrote:
> I have a very odd problem, I have purchased two of the ASUS usb tuners
> mentioned below in Stephen's post. I got the first, and was so impressed
> I decided to get a second. This is where the problem starts...
>
> When I connect the second tuner the load average on the machine jumps to
> 1 even when all the daemons etc have been shut down and the machine is
> as idle as it's possible to get a linux box.
>
> I have VirtualBox running on the machine hosting a copy of ubuntu 9.04
> server. With 1 tuner connected it's all good. Connect the second tuner
> and the ping times to this virtual machine jump from <1ms to 20-60ms
> (varying all over the place).
>
> Despite the problems above, the second tuner appears to work fine.
>
> The server is a Core 2 Duo E6600 2.4Ghz, 6GB Ram, running ubuntu 9.04
> server 32 bit, kernel version 2.6.28-15-server-52.
>
> I'm using the 32bit version of ubuntu because I'm testing SageTV for
> linux which only ships with 32bit binaries. I have PAE enabled to get
> access to the full 6GB of ram.
>
> I'm unsure how to progress from here.
>
> Any ideas anyone? seen something similar?
>
> Should I log a bug with the ununtu people or try and track down the devs
> for the DVB driver and log a bug with them?
>

First take a look at /proc/interrupts to see if there is a big jump over
time on any of the devices.

Next check what else is on the same USB controller, and keep an eye on
sharing USB 1.1 and USB 2 devices on the same controller.

I've used multiple USB DVB-T tuners on the same machine with no issue, but
they haven't been the same make/model.



--------------------------------------------
Steven Ellis - Technical Director
OpenMedia Limited - The Home of myPVR
email   - steven at openmedia.co.nz
website - http://www.openmedia.co.nz