kern/93083: [firewire] Detach of Firewire Harddisk not recognied properly

Gerhard Schmidt estartu at
Thu Mar 22 07:29:29 UTC 2007

On Thu, Mar 22, 2007 at 02:48:27AM +0000, Hidetoshi Shimokawa wrote:
> Synopsis: [firewire] Detach of Firewire Harddisk not recognied properly
> State-Changed-From-To: open->feedback
> State-Changed-By: simokawa
> State-Changed-When: Thu Mar 22 02:47:51 UTC 2007
> State-Changed-Why: 
> USB has always tree structures and any devices except hubs
> are leaves of the tree. This means that you can remove any device without
> disconnecting any other devices.
> On the other hand, ieee1394 allows daisy chains and you may sometimes
> want to remove a device between the host and a leaf device which is
> mounted on the host. The current default setting allow to remove physically
> such intermediate nodes without unmounting filesystems.

From my personal expirience that doesn't work. I had 3 external harddrives 
connected via FW. 

drive1 <-> host <-> drive2 <-> drive3 

Disconnecting drive1 and drive3 while drive2 is mounted worked sometimes 
(couldn't figure out what makes it fail) 

umounting and powering down drive2 (without physicaly disconnecting) causes
a panik when drive3 is mounted. 

The only secure way to disconnect any drive at the moment is to unmount 
any fw disk, disconnect the drive and remount the others. Everything 
else worked sometimes but most time the system crashed. 

As it seams to me that a busreset is triggerd by any disconnect or
powerchange and this causes a renumbering of the devices and leads 
to the crash. 

At the moment i have ext Harddisk and a DVD-Writer with firewire and a 
notebook with FreeBSD 6.2 and firewire. I can help you with testing. 


Gerhard Schmidt    | Nick : estartu      IRC : Estartu  |
Fischbachweg 3     |                                    |  PGP Public Key
86856 Hiltenfingen | EMail: estartu at          |  on request 
Germany            | 					|  

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