Re: 2.5.67-mm3: Bad: scheduling while atomic with IEEE1394 then hard freeze ( lockup on CPU0)

From: Philippe Gramoullé (philippe.gramoulle@mmania.com)
Date: Wed Apr 16 2003 - 18:52:09 EST


On 16 Apr 2003 16:35:10 -0700
Steve Kinneberg <kinnebergsteve@acmsystems.com> wrote:

  | > Since then, i only got these "reset storms" versions over versions. Not that i complain about
  | > but it's just that i hope that reporting bugs will be helpful to IEEE1394 developers, because
  | > if it worked once, then i don't see why i wouldn't work either with newer versions 8)
  |
  | The code that prints "ieee1394: Remote root is not IRM capable,
  | resetting..." was added almost 2 months ago to the 1394 SVN trunk, so
  | its still fairly recent and probably after 2.5.59.

I'm rather sure it was around 2.5.59 but i couldn't swear about the exact time frame
as it might be a BK snapshot at the time.

  | If this message repeats rapidly under recent 2.5.*, then there is a
  | problem with initiating a bus reset and forcing the local node to be
  | root.

Well with 2.6.57-mm3 + latest SVN checkout, it has about 1 such line per second
in my logs as soon as i turn on my DV Camcorder.

  
  | My recollection of the 1394 spec is that PHY packet needs to be sent out to
  | all nodes to clear the their root hold-off bit and the local node sets
  | its own root hold-off bit. The OHCI 1394 code doesn't appear to do
  | anything special to send a PHY packet (it does set the root hold-off bit
  | in the local PHY chip) and I wonder if that might not be the source of
  | this problem. Does anyone, who understands the PHY chip, know if it
  | automatically sends the appropriate PHY packet when this bit is set? If
  | not, we may need to add code to send it.
  |
  | If anyone can answer the one question I posed above, I'd greatly
  | appreciate it.

I'll happily let someone else answer :)

Thanks,

Philippe
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