Re: disable l2 cache on kirkwood devices (workaround #658904)
On Tue, 2012-09-11 at 03:57 -0700, Jonathan Nieder wrote:
> Ian Campbell wrote:
>
> > My main concern with doing this on the kernel side is that it will
> > eventually fall foul of the attempts to reduce everything to a single
> > kernel image, since the code will necessarily be quite kirkwood specific
> > and run very early on.
>
> Is it possible to do something reasonable if the extra features
> register is read first? (Please forgive my ignorance.)
I'm afraid I don't know either. Is this extra features register ARM
architectural or specific to the Kirkwood devices?
I think the cache control registers are implementation defined, so this
code would need to know it is running on a specific set of processors
before it would be safe to run it.
> > Martin's testing of di on ARM[0] suggests this issue isn't all that
> > widespread, which lead me to conclude that the risk of making a change
> > like this (either in the kernel or the installer/flash-kernel) for
> > Wheezy was not worth the chance of breaking some other kirkwood device.
>
> I think that's ok --- the change would be valuable upstream anyway,
> and it can filter into mainline and wheezy whenever it has had an
> appropriate amount of testing.
Ian.
--
Ian Campbell
Current Noise: Faal - My Body Glows Red
A soft drink turneth away company.
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