On Thu, 2008-09-11 at 10:23 +1000, Herbert Xu wrote:
Absolutely -- nobody should ever find themselves in that situation.
If a firmware changes in an incompatible way, its filename needs to
change too. The old one should still be available.
Even safer would be to have content-addressed firmware. Instead of
requesting it by filename, you request it by its md5sum. That way,
you're _guaranteed_ to have precisely what you expected.
But I think that's a bad idea too. As a general rule firmware isn't, and
shouldn't be, tied intimately to one particular version of the kernel.
It isn't even tied intimately to one particular version of the _driver_.
That's what we are doing already, as you say -- and what we should
always be doing.
And remember, ipw2200 isn't a particularly good example, because it's a
relatively recent driver and thus has always had its firmware shipped
_separately_ from the kernel.
All we're talking about here is the behaviour for the handful of older
drivers which I've recently dragged into this century by converting them
to use request_firmware(). Those drivers, by virtue of their age, are
mostly quite unlikely to receive _any_ kind of firmware update --
especially an update which changes their ABI.
--
David Woodhouse Open Source Technology Centre
David.Woodhouse@intel.com Intel Corporation
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