Re: [PATCH 4/4 update] firewire: fw-core: react on bus resets while the config ROM is being fetched

[Jarod Wilson]

On Friday 25 January 2008 11:53:49 am Stefan Richter wrote:
> read_rom() obtained a fresh new fw_device.generation for each read
> transaction.  Hence it was able to continue reading in the middle of the
> ROM even if a bus reset happened.  However the device may have modified
> the ROM during the reset.  We would end up with a corrupt fetched ROM
> image then.
>
> Although all of this is quite unlikely, it is not impossible.
> Therefore we now restart reading the ROM if the bus generation changed.
>
> Note, the memory barrier in read_rom() is still necessary according to
> tests by Jarod Wilson, despite of the ->generation access being moved up
> in the call chain.
>
> Signed-off-by: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx>
> ---
>
> First posted on 2007-11-01.  Update:  Barrier stays.

This is essentially what I've been beating on locally, and I've yet to hit 
another config rom read failure with it.

Signed-off-by: Jarod Wilson <jwilson@xxxxxxxxxx>


-- 
Jarod Wilson
jwilson@xxxxxxxxxx
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