Re: Enhanced PowerSaver driver

[Dave Jones <davej@redhat.com>]

On Wed, Jan 31, 2007 at 11:13:58PM +0100, Rafał Bilski wrote:
 > [...]
 > > 
 > > I have a board (IB798) with a Via Eden CPU (a C7 deviate). On kernel 2.6.16.38 I
 > > tried to compile and load Via's longhaul driver. When I started cpufreq, the O/S
 > > crashed.
 > > 
 > This is rather bad sign. Looks like I spoke to soon.
 > > If e.g. Rafał create som patches for the original longhaul driver, from ideas
 > > based on Via's code, I will install them, test and give feedback.
 > > 
 > Thanks.
 > 
 > After looking into code I have found two things:
 > - it is using "disable bus master bit on each PCI device"... for C7?!,
 > - it is using current CPU f and vcc to find table for it. I don't like 
 > this idea. If CPU has min/max info why not use it? Strange thing in C7 
 > is that it is starting at lowest supported frequency. BIOS has to switch it 
 > to max. As You can read at viaarena, BIOS is only doing it when "optimized 
 > defaults" are loaded. Looks like it isn't default. What will happen if 
 > driver will search table for CPU running at lowest frequency? Probably 
 > processors with different max can have same min frequency.
 > 
 > Dave: Can I repost e_powersaver with "experimental" and some small 
 > changes? Sorry.

Sure, feel free.
I've got 'look at the via driver' on my TODO, but I've got a ton of stuff
to dig through after having been away for the last two weeks, so it may
take me a while to get around to it. If you beat me to it, all the better :-)

		Dave

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