[mythtv-users] HD-PVR: Encoding Errors Running 0.22

Alan Young ayoung at teleport.com
Wed Dec 2 07:35:37 UTC 2009

Alan Young wrote:
> My cable experiment in the other thread kinda worked.  With the new 
> cable and kernel I'm now seeing timeout messages like this in the log:
>  usb 1-1: mythbackend timed out on ep1in len=0/8192
> Which is odd cause device 1-1 is the hub not the hdpvr itself.
> That's lead me into digging into the source of the unofficial .21 fixes 
> patch and comparing it to what's currently in the official source.
> I noticed a very interesting change in Jean Yves 49_hdpvrsupport.dpatch. 
> There's a change in  DeviceReadBuffer::Poll(void) that increases the 
> poll timeout that seems to point to "Error poll giving up" message.  
> Here's the change...
> -        int ret = poll(&polls, 1 /*number of polls*/, 10 /*msec*/);
> -        if (IsPauseRequested() || !IsOpen() || !run)
> +        int ret = poll(&polls, 1 /*number of polls*/, 250 /*msec*/);
> I'm going to try to increase timeout that first and see what happens.

I made that change and some other changes to make the function similar to the
.21 fixes patch.  That seemed to reduce the flickering somewhat and also
allowed a couple of recordings to make it all the way through.  I've attached
the patch to this email.

A couple of other thoughts...

Is your CPU single core or multi core?  If multi, are you using irqbalance?

Is your system using cpufreq?  If so, which scaling governor are you using?

I have been using the ondemand governor.  And up to this evening, I have not 
used irqbalance.  I did three recordings tonight with the attached patch, the 
performance governor instead of the ondemand governor and irqbalance running. 
  Myth made it all the way though all of them (2 hours total on two different 
channels) without a problem.

I'm curious to know if anyone switches to the performance governor without the 
patch and without irqbalance and sees any improvement.

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