[pvrusb2] periodic, sporadic hanging

[Mike Isely]

On Thu, 25 Jan 2007, Nick Cabatoff wrote:

> Hi all,
> 
> First, thanks Mike (and those who came before you) for the driver.
> Overall I'm very happy with it.  There's just one problem: every few
> days, for reasons that are unclear to me, I get this message in the
> log:
> 
>   pvrusb2: Failed to submit write-control URB status=-19

Hmm.  That's ENODEV.  Sounds like a fairly severe error in the USB core.  
The pvrusb2 driver itself never generates this error.

My first guess is that you've got USB connectivity problems.  Possible 
bad cable, flakey controller, interference from another device (though I 
think that last one is pretty unlikely).

An error like that is probably going to kill the driver.


> 
> I'm running mythtv, and the backend stops responding after this.  If I
> kill the backend, it becomes a zombie and won't die.  I can't unload
> the pvrusb2 module at this point.  As far as I know my only option at
> this point is to reboot.  Even rebooting doesn't seem to do the trick:
> although the device appears to reinitialize properly according to the
> logs, I'm not able to open the device unless I powercycle it.  (And
> powercycling without rebooting isn't sufficient either.)

That sounds pretty sucky.

There might be a pvrusb2 bug which is causing the driver to "stick", 
thus jamming everything around it.  Can you e-mail me the surrounding 
log messages?  Just send it direct, no need to add more noise to the 
list.

However with that said, I think the root cause might be a USB hardware 
issue here.


> 
> Initially I ran with the standalone version (20061230) on 2.6.17
> (ubuntu edgy stock kernel).  Then my frustration with this problem led
> me to install the 2.6.19.2 kernel from kernel.org, and the problem
> reoccured using the in-kernel version.  I just installed the latest
> standalone version, again on the 2.6.19.2 kernel.  Since I don't see
> anything in the changelog relating to my issue, I'm expecting the
> problem to reoccur.  What debug options should I set (and where) in
> order to dig deeper into this problem?

This would be consistent with a hardware problem; i.e. no recent driver 
changes seem to affect it.  Also nobody else (that I know) is 
experiencing an issue like this.  The standalone driver snapshots are 
going to be more recent.  What's in 2.6.19 is a vintage that probably 
goes back to around Sep / Oct 2006.  What will be in 2.6.20 is later 
(but still several months back); this lag is just an effect from the 
process for pulling up changes into the kernel.

There's a lot of debug messages you can turn on.  Please read the 
pvrusb2 docs, as there is a fairly decent description of this.  You can 
find the relevant info here:

http://www.isely.net/pvrusb2/usage.html#Logging

  -Mike

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