[mythtv-users] HD-PVR / Mythtv robustness

[Ken Bass]

On 2/12/2011 2:12 PM, Michael T. Dean wrote:
> On 02/12/2011 10:00 AM, Ken Bass wrote:
>> Occasionally something happens that causes a zero length recordin with
>> the HD-PVR. When this happens I notice that the blue recording light is
>> on. I am unsure if this is because it is 'stuck on' from a previous
>> recording or related to the failed recording.
>>
>> My question is why can't Mythtv gracefully recover from this and in
>> particular switch to using another tuner? When this condition triggers,
>> the log shows:
>>
>> 2011-02-07 11:00:12.308 Channel(/dev/video-hdpvr1) Error:
>> SetInputAndFormat(6, NTSC)
>>                          while setting input (v4l v2)
>>                          eno: Connection timed out (110)
> ...
>> 2011-02-07 11:00:42.330 Started recording: "Dog the Bounty Hunter":"No
>> Luv Still": channel 2223 on cardid 6, sourceid 2
>> 2011-02-07 11:00:43.573 AnalogSM(/dev/video-hdpvr1), Error: Start
>> encoding failed
>>                          eno: Resource temporarily unavailable (11)
>>
>> ( snip 26 minutes of repeats ...)
> Looks like you need to change your timeouts.  In 0.24+, HD-PVR users 
> must set appropriate (read, somewhere on the order of 10s) timeouts in 
> mythtv-setup.

My timeout is set in the order of 10s. If you look at the log I posted,
the timestamps indicate 10s inbetween each timeout print.
However, I cannot believe that is the issue here. For a HD-PVR device,
mythtv should NEVER be trying to SetInputAndFormat to NTSC.
It seems to be an error that is not being handled and something is
falling through to an invalid case. And I guess this raises another bug
as to why mythtv-setup is not setting the timeout to 10 or so as a
default when adding HD-PVR type tuner. If I recall, it defaults to
perhaps 3 or 4 seconds.
I only discovered that it needed to be increased because livetv does not
working with the default. Since my channel change script sleeps for 4
seconds, channel changes in livetv would timeout unless I increased it.
I discovered this by trial and error.
>> I have no idea why in this particular case it is hitting the NTSC/ATSC
>> case for an HD-PVR, especially since it has just properly finished
>> recording something the previous hour. However, if there are these
>> failures returned from SetInputAndFormat, why doesn't MythTV try to use
>> another tuner.  Despite printing all these messages for the full hour,
>> MythTV merrily transitions to the Recorded state as if everything was okay.
> Because we pretty much expect you to use working (and properly 
> configured) hardware.  The scheduling complexity increases exponentially 
> when you have to deal with "broken, not available" hardware and fail-over.
I am not in a position to say if the HD-PVR is at fault or MythTV. If
Mythtv is sending illegal/inappropriate v4l commands, who knows what
state that might put the HD-PVR driver into.

Reschedule complexities aside, it should at least stop the recording and
not mark it as completed, so that it can be rescheduled automatically.
Printing error messages for an hour
and marking it as recording certainly is not the way to handle it.