[mythtv-users] Strange networking issue with Acer Revo AR1600 on GBit

[Johnny Walker]

On Wed, Apr 28, 2010 at 8:07 AM, Michael Lynch <lynchmv at gmail.com> wrote:
> On Wed, Apr 28, 2010 at 8:49 AM, Daniel Born <born_daniel at yahoo.com> wrote:
>>
>> > On 04/26/2010 10:42 AM, James Crow wrote:
>> >> On Mon, Apr 26, 2010 at 10:08 AM, Daniel Born <born_daniel at yahoo.com> wrote:
>> >>>
>> >>> Could it be the network driver (forcedeth) that's been upgraded on 10.04?
>> >>>
>> >>
>> >> I remember having all sorts of issues with the forcedeth driver back
>> >> in (AFAIR) 7.04 and 7.10 days. It was so bad that for a while I had to
>> >> use a PCI NIC. I do not remember exactly which motherboard I had that
>> >> was causing the problems.
>> >
>> > There have been a lot of changes in forcedeth in recent kernels. As mine
>> > works fine on a 100 Mb/s network with kernel 2.6.29, I assume that most
>> > of the modifications have been for 1000 Mb/s nets.
>>
>> Well, in my onging effort to (correctly) debug this problem, this is what I know now:
>>
>> Mythbuntu 9.10 32-bit fully updated (kernel 2.6.31.20): doesn't work reliably
>> Ubuntu 10.04 RC4 64-bit fully updated (kernel?): works reliably
>> Xubuntu 9.10 64-bit fully updated (kernel 2.6.31.20): works reliably
>> Mythbuntu 9.10 64-bit fully updated (kernel 2.6.31.20): doesn't work reliably
>>
>> So it might appear to have a relationship with the Mythbuntu package.
>>
>> My next step will be to reinstall Xubuntu 9.10 and install Mythtv on that.
>>
>> Any suggestions, hints, things to try, etc. are welcome.
>>
>> Thanks,
>> Daniel
>
> Now that you mention it (and I read it) my Revo with Mythbuntu
> exhibits similar behavior (I think).  When starting playback on the
> Revo, it will play for about 1 minute then fail with prebuffter pauses
> (http://mythtv.beirdo.ca/ircLog/channel/1/2010-04-17:11:32/2010-04-17:12:37).
>  I have found that *any * activity on the backend (ls, iptraf,
> pwd...etc) will clear up the prebuffer pauses and allow playback to go
> without a hitch.  So, I'm not sure if it's something in the backend
> (since activity there clears up the issue) or if I'm seeing the same
> issue as you.
>
> My simple workaround right now (to keep WAF up) is to just run iptraf
> from my desktop in the office in an ssh session on the backend.
>
> My backend is Slackware 13.0 kernel 2.6.30.5 and the Revo frontend is
> Mythbuntu 9.10 kernel 2.6.31.20.  Next time I have some downtime on
> the box I may just load Slackware and see if the issue goes away.


I'm running MythBuntu 9.10 karmic on my Revo frontend with kernel
2.6.31-20-generic and I don't have any issues with the networking.
1080i recorded off my HDHR plays fine with no prebuffering pauses.

If adding activity on the backend seems to alleviate your issue I
would suspect that your cpu is being throttled down on the backend due
to low activity. Have you done ALL of the steps at
http://www.mythtv.org/wiki/Troubleshooting:Prebuffering_pause ?

Why would your distro, kernel and make/model of frontend be an issue
when adding activity to the backend machine seems to remediate the
issue?

Please understand I'm not trying to argue but rather trying to say
1)This combo works for me. 2)Here's some steps you can try.

-Johnny