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Subject: Re: [PATCH] ehea: Add kdump support
To: michael@ellerman.id.au
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From: Christoph Raisch <RAISCH@de.ibm.com>
Date: Mon, 26 Nov 2007 11:45:02 +0100
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Michael Ellerman wrote on 26.11.2007 09:16:28:
> Solutions that might be better:
>
>  a) if there are a finite number of handles and we can predict their
>     values, just delete them all in the kdump kernel before the driver
>     loads.

Guessing the values does not work, because of the handle structure
defined by the hypervisor.

>  b) if there are a small & finite number of handles, save their values
>     in a device tree property and have the kdump kernel read them and
>     delete them before the driver loads.

5*16*nr_ports+1+1=   >82. a ML16 has 4 adapters with up to 16 ports, so the
number
is not small anymore....
The device tree functions are currently not exported.

If you crashdump to a new kernel, will it get the device tree
representation
of the crashed kernel or of the initial one of open firmware?

>  c) if neither of those work, provide a minimal routine that _only_
>     deletes the handles in the crashed kernel.

I would hope this has the highest chance to actually work.
For this we would have to add a proper notifier chain.
Do you agree?

>  d) <something else>

Firmware change? But that's not something you will get very soon.

Christoph R.

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