[mythtv-users] Suddenly flaky firewire

[Christopher Meredith]

On Fri, Feb 4, 2011 at 11:41 AM, GZ <gzornetzer.lists at gmail.com> wrote:
> On Fri, Feb 4, 2011 at 9:22 AM, Christopher Meredith <chmeredith at gmail.com>
> wrote:
>>
>> I have been using firewire as an alternate tuner for clear QAM
>> stations accessible via my cablebox, and as a channel changer for the
>> same cable box and an HD-PVR. It worked fine until I updated Ubuntu to
>> Maverick (10.10). Now, the firewire system seems to be really
>> unstable. It keeps "collapsing" during recordings. When that happens,
>> I get the following in dmesg:
>>
>> [280735.091273] firewire_ohci: failed to read phy reg
>>
>> And after that plugreport shows this:
>>
>>
>> Host Adapter 0
>> ==============
>>
>> Node 0 GUID 0x0000000000000000
>> ------------------------------
>> libiec61883 error: error reading oMPR
>> libiec61883 error: error reading iMPR
>>
>> Node 1 GUID 0x0400000004000000
>> ------------------------------
>> libiec61883 error: error reading oMPR
>> libiec61883 error: error reading iMPR
>>
>> The only way I've been able to find to get it back is rebooting. This
>> is pretty frustrating. Does anyone have any suggestions for how to
>> address this?
>
> What distribution and kernel were you running before when things worked?
> Which kernel are you running on Ubuntu 10.10 now? Could you give the 'uname
> -a' output?
> Do you know offhand which firewire controller you have? (Should be able to
> find this out by poking around the dmesg from bootup, or using 'lspci'
> Do you happen to know if you were previously running the "old" firewire
> stack as opposed to the new "juju" stack?  Generally, the new stack seems to
> behave better with most firewire devices, but there are always possible
> exceptions.  I would hope that Ubuntu 10.10 is using the new stack.
> Good luck with the debugging.

Thanks for the reply. The upgrade was actually a jump from Mythbuntu
9.10 to Ubuntu 10.10 via the distribution upgrade tool. According to
uname, my current kernel is:

Linux farmer 2.6.35-25-generic #44-Ubuntu SMP Fri Jan 21 17:40:44 UTC
2011 x86_64 GNU/Linux

I *believe* the last kernel I was using successfully was
2.6.32-27-generic. The firewire card is, according to lspci:

04:00.0 FireWire (IEEE 1394): JMicron Technology Corp. IEEE 1394 Host
Controller (prog-if 10 [OHCI])
	Subsystem: JMicron Technology Corp. IEEE 1394 Host Controller
	Flags: bus master, fast devsel, latency 0, IRQ 16
	Memory at fdbff000 (32-bit, non-prefetchable) [size=2K]
	Memory at fdbfe000 (32-bit, non-prefetchable) [size=128]
	Memory at fdbfd000 (32-bit, non-prefetchable) [size=128]
	Memory at fdbfc000 (32-bit, non-prefetchable) [size=128]
	Capabilities: <access denied>
	Kernel driver in use: firewire_ohci
	Kernel modules: firewire-ohci, ohci1394

I can confirm that I am using the new juju firewire stack. Maybe the
best option for me at this point is to try switching back to the old
one. Any other thoughts?

Thanks!