Bug 11349 - connection loss when an additional device is plugged into a 6-port hub
connection loss when an additional device is plugged into a 6-port hub
Status: CLOSED CODE_FIX
Product: Drivers
Classification: Unclassified
Component: IEEE1394
All Linux
: P1 normal
Assigned To: Stefan Richter
:
Depends on:
Blocks: 10307
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Reported: 2008-08-15 08:57 UTC by Stefan Richter
Modified: 2009-02-09 14:35 UTC (History)
0 users

See Also:
Kernel Version: all
Tree: Mainline
Regression: ---


Attachments

Description Stefan Richter 2008-08-15 08:57:24 UTC
If there is a bus consisting of PC--hub--device_A and another device_B is plugged in into the hub, then the PC may briefly loose contact with device_A. This is troublesome if a filesystem was mounted device_A or the device was otherwise in use.

This only happens with _some_ devices as device_B, but presumably with all 6-port hubs.  (There is only one known 6-port PHY chip, hence all 6-port hubs are very similar WRT to PHY functionality.)  Affected are both the ieee1394 and the firewire driver stack.  Windows XP and Mac OS X are known to handle this without connection loss, i.e. without danger to mounted filesystems.

More data reported here:  http://marc.info/?l=linux1394-user&m=121875239304371
Comment 1 Stefan Richter 2008-08-16 05:11:18 UTC
Proposed patches:

[1/3] ieee1394: regression in 2.6.25: updates should happen before probes
http://lkml.org/lkml/2008/8/16/85

[2/3] ieee1394: don't drop nodes during bus reset series
http://lkml.org/lkml/2008/8/16/86

[3/3] ieee1394: sbp2: let nodemgr retry node updates during bus reset series
http://lkml.org/lkml/2008/8/16/88

They work for me but need to be confirmed by the original reporter.
Comment 2 Stefan Richter 2008-08-18 15:18:26 UTC
Fix confirmed by the original reporter (Damien Benoist).

To do:
  - Get the ieee1394 fixes upstream and into stable.
  - Implement a similar fix in the new firewire stack.
Comment 3 Stefan Richter 2008-10-09 08:19:09 UTC
ieee1394 fixed upstream (2.6.27-rc in August),
firewire not yet done
Comment 4 Stefan Richter 2009-01-17 13:58:45 UTC
firewire fix posted:  http://lkml.org/lkml/2009/1/17/156
Comment 5 Stefan Richter 2009-02-09 14:35:34 UTC
firewire fixed in 2.6.29-rc4

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