Re: [PATCH 002/002] de2104x: support for systems lacking cache coherence

[Risto Suominen <risto.suominen@gmail.com>]

2009/2/9 Krzysztof Halasa <khc@pm.waw.pl>:
>
> That means the consistent/coherent mapping isn't really
> consistent/coherent (uncached), right? Perhaps there is some way to fix
> this instead of changing the drivers to avoid the problematic area?
>
Yes.

The other way could be to add a config parameter that allows to
explicitly set CONFIG_NOT_COHERENT_CACHE. I have not tried this,
probably because the necessary code wasn't in arch/powerpc until
2.6.21.

Anyway, now I have tested with 2.6.24, and the problem still exists.

Apropos changing the driver, I would like to point out, that leaving
my proposed config parameter to its default value means not changing
the driver.

> Potentially any driver is affected by such coherency problem, this can't
> be specific to 21040.
>
I agree. That talks for the config solution.

Risto