Re: [PATCH 7/7] [RFC] APM emulation driver for class batteries

From: Russell King
Date: Mon Apr 16 2007 - 17:34:52 EST


On Tue, Apr 17, 2007 at 01:08:29AM +0400, Anton Vorontsov wrote:
> On Mon, Apr 16, 2007 at 09:24:21PM +0100, Russell King wrote:
> > Utterly unsafe. What happens if some other module gets loaded which
> > does this, and then this module is unloaded followed by the other
> > module. Result: Oops.
>
> Right. And loading two modules which changing apm_get_power_status
> is a race already. Thus, APM interface needs a mutex.
>
> Or pda_power should be marked "bool" in Kconfig, as it is done
> in arch/arm/common/sharpsl_pm.c. Sharpsl_pm is safe only because it
> can't be a module.
>
> Personally I'd keep things as is for now (i.e. I'd want tristate for
> PDA_POWER, not bool). Later APM API can be fixed.

Experience shows "Later" more often than not means "never", inspite
of what is said at the time the word is used...

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of:
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