Re: [PATCH 1/2] PM / Runtime: Add sysfs switch for disablingdevice run-time PM (rev. 2)

From: Pavel Machek
Date: Fri Feb 05 2010 - 01:28:15 EST



> > > + * The default for all devices is "auto", which means that devices may be
> > > + * subject to automatic power management, depending on their drivers.
> >
> > Is it wise to specify 'auto' default value for devices without runtime
> > pm?
>
> Yes, it is. It means the user space doesn't care whether or not the device is
> power managed at run-time.

Well, defaulting to 'on' for drivers when runtime pm is experimental
seems logical. and there will be such drivers...

> > > + len = cp - buf;
> > > + if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0)
> > > + pm_runtime_allow(dev);
> >
> > parenthesis after sizeof?
>
> This notation is used throughout this file too.

...but is inconsistent with rest of kernel.

> > Do I read it correctly that all of
> >
> > "auto"
> > "auto\n"
> > "auto\non\nIm confused"
> >
> > will switch to auto?
>
> Perhaps it would, but what exactly is the problem with that?

That apps will start depending on such broken behaviour?
Pavel
--
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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