[Fwd: Re: [linux-dvb] Freecom DVB-T USB Stick Kernel OOps]

simonwoodward at blueyonder.co.uk simonwoodward at blueyonder.co.uk
Thu Dec 29 22:53:22 CET 2005


Thanks Patrick.

Is this a driver problem then, as the card works fine under M$?
Is the driver somehow supposed to limit the power drawn?

In addition, using tzap on its own causes the same thing but only tzap and
the stick freeze.  The system is usable, so I might be able to get another
dump.

Ta

> Received the following kernel oops whilst using scandvb on:
>> uname -a
> Linux laptop 2.6.14-1.1644_FC4 #1 Sun Nov 27 03:25:11 EST 2005 i686 i686
i386 GNU/Linux
> (Dell Latitude C600)
>
> Sorry about the size, but I'm not sure which of this lot is important!!!
This happens everytime I use scandvb or when scanning using Kaffeine
(which I think is the same thing :-)).  Sometimes the whole lot just
freezes and I have to hard reboot.

Yes!! Finally I see what the problem is people pointing out all the time 
in previous threads:
Eg.: http://www.linuxtv.org/pipermail/linux-dvb/2005-December/006853.html

and other threads (such as Twinhan Alpha Twincard).

Those cards in running mode exceed the USB power specification
(500mA/device) and that's why:

> Dec 28 00:56:39 localhost kernel: dvb-usb: bulk message failed: -71
(1/1) Dec 28 00:56:40 localhost kernel: hub 1-0:1.0: port 1 disabled by
hub (EMI?), re-enabling...
> Dec 28 00:56:40 localhost kernel: usb 1-1: USB disconnect, address 3

And unfortunately the dvb-usb (or rather the dvb-core) is not capable of 
hotplug-events and that's why:

> Dec 28 00:56:40 localhost kernel: Unable to handle kernel paging request
at virtual address d4b0a2a4
> Dec 28 00:56:40 localhost kernel: EIP is at dvb_demux_poll+0x28/0x61
[dvb_core]

Because the unplug caused the driver to deallocate the dvb-structures 
while the device is used by an application.

> Dec 28 00:56:41 localhost kernel: usb 1-1: new full speed USB device
using uhci_hcd and address 4
> Dec 28 00:56:41 localhost kernel: dvb-usb: found a 'WideView WT-220U
PenType Receiver (Typhoon/Freecom)' in warm state.
> Dec 28 00:56:41 localhost kernel: dvb-usb: will use the device's
hardware PID filter (table count: 15).
> Dec 28 00:56:41 localhost kernel: DVB: registering new adapter (WideView
WT-220U PenType Receiver (Typhoon/Freecom)).
> Dec 28 00:56:41 localhost kernel: DVB: registering frontend 0 (WideView
USB DVB-T)...
> Dec 28 00:56:41 localhost kernel: dvb-usb: schedule remote query
interval to 300 msecs.
> Dec 28 00:56:41 localhost kernel: dvb-usb: WideView WT-220U PenType
Receiver (Typhoon/Freecom) successfully initialized and connected. Dec
28 00:56:42 localhost kernel: dvb-usb: recv bulk message failed: -110

After sometime the USB hub allows the device to show up again. (it is 
still in warm state, that's why there is no firmware download).

Patrick.

--
   Mail: patrick.boettcher at desy.de
   WWW:  http://www.wi-bw.tfh-wildau.de/~pboettch/







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