OpenFirmware devices and hotplug events

Greg KH greg at
Wed Mar 17 09:37:12 EST 2004

On Wed, Mar 17, 2004 at 09:25:44AM +1100, Anton Blanchard wrote:
> > Eeek!  Hm, I thought this tree was moved under /sys/firmware which is
> > where it rightly belongs.  If that is done, then you get all the hotplug
> > events you could ever ask for, for free :)
> Basically we want a mechanism to receive EEH errors in userspace and
> decide whether we can recover from them by hotplugging the device.
> EEH errors are PCI errors. eg we get a target abort on a slot, the
> hardware locks the slot out and we get notification. Its possible this
> is a transient fault and we should reset the card (ie hotplug it out and
> in). If it happens to much we want to deconfigure the card.
> This policy obviously lives in userspace. How do you suggest we hook it
> up?

As a hotplug event?  That should work, right?

> > Is anyone working on moving this tree to sysfs?
> Not at the moment. Too many things refer to it. We'll remove
> /proc/device-tree the day you get rid of /proc :)

Heh, don't tempt me :)

Remember, /proc is only for "processes", not device stuff.

> But seriously it would be nice to merge sysfs and the device-trr, we
> can look at this in 2.7.

It looks like a portion of the device-tree is in sysfs today, with the
different busses, right?  It shouldn't be that big of a leap.


greg k-h

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