Prev: warning at serial_write_room and serial_write
Next: Quote Price
From: Langsdorf, Mark on 19 Apr 2010 09:50

> Date: Fri, 16 Apr 2010 22:40:58 +0200
> From: Josselin Mouette <joss(a)debian.org>
> To: linux-kernel(a)vger.kernel.org
> Subject: Athlon L110 CPU and powernow-k8
> X-Mailer: Evolution 2.29.92.1
> Message-ID: <1271450458.6794.33.camel(a)tomoyo>
>
> In both cases, the issue is the same: the DSDT table provided by the
> BIOS does not include the P-states. Waiting for a hypothetical BIOS
> update that would fix this bug requires some faith that I
> don't have. It is possible to work around this by compiling the
> kernel with a custom DSDT table with appropriate P-states patched
> in, however I consider this a developer hack.
>
> I wonder what is possible to do to support this CPU correctly in the
> kernel. The only sane solution I can think of is to hardcode the
> P-states for this CPU model in the powernow-k8 driver itself.

I think that hard-coding P-states into the PowerNow
driver is not a mantainable solution.

I don't quite understand why the you think that
a custom DSDT as a BIOS hack, but think that
adding custom frequencies to the driver itself is
acceptable.

The last time this issue came up on cpufreq, Dave
Jones nixed a general solution to add custom P-states
through the driver on the grounds that people would
undervolt their systems, causing a lot of screwy,
unpredictable behavior. I agreed with his opinion
then and I don't see anything in this mesage to
change that view.


--Mark Langsdorf
Operating System Research Center
AMD

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo(a)vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
 | 
Pages: 1
Prev: warning at serial_write_room and serial_write
Next: Quote Price