Re: node not destroyed on unplug

[Stefan R. <st...@s5...>]

On Dec 20 Carl Karsten wrote:
> un/re-plugging the cable. waiting a few seconds between each (but not
> watching syslog, so maybe didn't wait long enough...)  - 3 or 4 worked
> fine, fw2,3 created/destroyed as expected, then I unplug, and fw2
> doesn't destroy:
> 
> juser@pc8:~$ ls /dev/fw?
> /dev/fw0  /dev/fw1  /dev/fw2
> 
> and syslog has a ton of
> Dec 20 09:08:22 pc8 kernel: [ 2325.059013] firewire_ohci: AR
> evt_bus_reset, generation 0
> .... 0-255
> loop that 25 times.

This can happen if a process keeps /dev/fw2 open, but in this case I think
the problem is that your bus reset series was never finished by a proper
self-ID-complete event.

Only when the controller received selfIDs after bus reset, firewire-core
gets to work and check which nodes are there and which are gone.

[...]
> Dec 20 09:08:23 pc8 kernel: [ 2325.704727] firewire_ohci: 2 selfIDs, generation 30, local node ID ffc1
> Dec 20 09:08:23 pc8 kernel: [ 2325.704744] firewire_ohci: selfID 0: 80458882, phy 0 [p..] S400 gc=5 +0W Lci
> Dec 20 09:08:23 pc8 kernel: [ 2325.704758] firewire_ohci: selfID 0: 8145ccd4, phy 1 [c--] beta gc=5 -3W Lc
> Dec 20 09:08:23 pc8 kernel: [ 2325.704797] firewire_ohci: 2 selfIDs, generation 8, local node ID ffc0
> Dec 20 09:08:23 pc8 kernel: [ 2325.704811] firewire_ohci: selfID 0: 80458882, phy 0 [p..] S400 gc=5 +0W Lci
> Dec 20 09:08:23 pc8 kernel: [ 2325.704824] firewire_ohci: selfID 0: 8145ccd4, phy 1 [c--] beta gc=5 -3W Lc

Here, both controllers got a self-ID-complete event with 2 nodes present
in each event.

[...]
> Dec 20 09:08:32 pc8 kernel: [ 2334.764102] firewire_ohci: AR evt_bus_reset, generation 9
> Dec 20 09:08:32 pc8 kernel: [ 2334.764270] firewire_ohci: 1 selfIDs, generation 9, local node ID ffc0
> Dec 20 09:08:32 pc8 kernel: [ 2334.764283] firewire_ohci: selfID 0: 807f8842, phy 0 [-..] S400 gc=63 +0W Lci

Here, only one controller reports a self-ID-complete event, now with the
local node being the only one on the bus.  But the other controller is
notably silent.

> Dec 20 09:08:32 pc8 kernel: [ 2334.764416] firewire_ohci: AT spd 0 tl 00, ffc0 -> ffc1, evt_missing_ack, QW req, fffff0000234 = c000001f

Alas firewire-ohci does not log the PCI device name of the card...

Anyhow.  As a rule of thumb, anything is possible with faulty hardware.
Anything bad, that is.
-- 
Stefan Richter
-=====-==-== ==-- =-=--
http://arcgraph.de/sr/