[mythtv] Firewire STB keeps jumping ports in 0.21-fixes. Suggestions?

[William Munson]

Simon Koch wrote:
>
>
> On Wed, Feb 20, 2008 at 4:29 PM, Steven Adeff <adeffs.mythtv at gmail.com 
> <mailto:adeffs.mythtv at gmail.com>> wrote:
>
>     On Feb 17, 2008 9:26 AM, William Munson <w.munson at comcast.net
>     <mailto:w.munson at comcast.net>> wrote:
>     >
>     > Daniel Kristjansson wrote:
>     > > On Sat, 2008-02-16 at 22:03 -0500, William Munson wrote:
>     > >
>     > >> First off, sorry to post this to the dev list however I have
>     not gotten
>     > >> any answers in the users list.
>     > >>
>     > >> I am testing the 0.21-fixes branch on ubuntu and am running
>     into a
>     > >> situation where if I accidentally tune a bad channel with my
>     DCT6416 STB
>     > >> it will cause the STB to switch ports from 1 to 0 and back
>     again. The
>     > >> port is still stable and firewire_tester will still capture
>     packets in
>     > >> broadcast mode just fine however the backend does not realize
>     that the
>     > >> port has moved even though the UUID is still the same. Am I
>     missing
>     > >> something or is there a bug that causes the backend end to
>     miss the fact
>     > >> that the port has changed? What can I do to troubleshoot this and
>     > >> provide more useful info?
>     > >>
>     > >
>     > > LinuxFirewireDevice::UpdateDeviceListItem() should update the
>     device
>     > > list when there is a reset, and
>     LinuxFirewireDevice::HandleBusReset()
>     > > should reconnect the device when it calls
>     iec61883_cmp_reconnect(),
>     > > but it doesn't always work. The Linux firewire guys weren't too
>     > > interested in fixing this driver problem when I discovered it
>     (though
>     > > they were helpful in many ways with the firewire code.) They were
>     > > working on a new driver which I understand should be immune to
>     these
>     > > types of problems. I no longer use the firewire recorder, so
>     this is
>     > > not something I've looked into further.
>     > >
>     > > The OSX FirewireRecorder does recover in these instances. But
>     it has
>     > > it's own problems. The OSX driver devs decided to always issue
>     a bus
>     > > reset when an application starts or stops using firewire, so
>     you end
>     > > up losing portions of your recordings if you have more than
>     one STB
>     > > or have some other firewire devices on the same bus.
>     > >
>     > > The upshot is that AFAICT the bug is in the Linux Firewire
>     drivers and
>     > > not in MythTV; unless you track down the bug in the drivers
>     yourself
>     > > it is not likely to be fixed until the whole firewire driver
>     stack is
>     > > replaced with the next generation firewire stack. BUT, it has
>     been a
>     > > while since I've been on top of this so you might want to read
>     up on
>     > > the posts in the linux1394-devel at lists.sourceforge.net
>     <mailto:linux1394-devel at lists.sourceforge.net> the next gen
>     > > driver might be in a usable state at this point, or it might
>     have been
>     > > abandoned, and/or someone might have written some patches to
>     fix the
>     > > problem in the existing drivers.
>     > >
>     > > Searching the linux1394 mailing list for "bus reset" might
>     give you
>     > > something useful...
>     > >
>     > > -- Daniel
>     > >
>     > >
>     >
>     > Thank you for the info. One more question. Is there a location
>     in the
>     > database that stores the current port? I was thinking of writing a
>     > channel change script that would take a look at plugreport on each
>     > channel change and update the database before changing channels.
>     If myth
>     > looks at this variable when setting up a recording then I could
>     > dynamically update things whenever I change channel. It would
>     also allow
>     > me to stabilize the connection if required. This looks to be
>     easier than
>     > trying to patch the ubuntu 1394 stack.
>     >
>     > TIA,
>     > William
>
>     I have a channel change script that uses the Firewire GUID for the box
>     in question to change the channel. It doesn't affect the database but
>     since I've started using it (to fix 0-byte recordings) I've yet to
>     miss a firewire recording. The downside is you have to manually give
>     mythtv-setup the GUID of the box in the channel changer field, but
>     otherwise it works great.
>
>     http://www.mythtv.org/wiki/index.php/User:Steveadeff#6200changer.sh
>
>     --
>     Steve
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>
>
> I have a similar script.  I made 2 wrappers around it, each with the 
> GUID of one of my cable boxes.  I found that slightly more convenient 
> than typing them in in mythtv-setup.
>
>     Simon

Looks like we all had slightly different solutions. Since I only have 
one stb I wrote a script that checks plugreport to find the node by GUID 
then resets that port/node before changing channels. So far its recorded 
everything as requested. I have that capture device set as my primary 
signal source with my pvr-250's as backup so it sees lots of activity. 
If anyone is interested I will post the script.

William