[U-Boot] [PATCH] arm: pxa: config option for PXA270 turbo mode

Marek Vasut marex at denx.de
Tue May 21 21:25:33 CEST 2013


Dear Sergey Yanovich,

> On Tue, 2013-05-21 at 13:22 +0200, Marek Vasut wrote:
> > > Actually, I wonder if Linux's cpufreq still does depend on bootloader
> > > speed settings. Especially the turbo bit. Can you please check that?
> > > It'd be interesting to know ...
> > > 
> > > I'd say enable it by default ... I probably have all the PXA devices
> > > supported in U-Boot and I'm quite sure none of them will mind ;-)
> > 
> > Still, I'm surprised it wasn't enabled. I recall seeing it enabled. Weird
> > ...
> 
> Yes, you are right. Linux's cpufreq-pxa2xx.c always sets the turbo bit.
> 
> However, if CONFIG_CPU_FREQ is not set (my case), bootloader's settings
> are used.
> 
> I work on a system that has focus on low latency (industrial controller)
> rather than battery life (since it has no battery).

So why not just make this patch into

-(2)
+(0xb)

instead of adding new (and undocumented ...) macro?

Best regards,
Marek Vasut


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