Re: [PATCH v2 2/2] ARM: at91: pm: switch to the PIE infrastructure

[Alexandre Belloni]

On 29/06/2016 at 08:12:21 +0200, Alexander Stein wrote :
> > +#if defined(CONFIG_CPU_V7)
> > +	dsb();
> > +	wfi();
> > +#else
> > +	asm volatile ("mcr	p15, 0, %0, c7, c0, 4" \
> > +		      : : "r" (0) : "memory");
> > +#endif
> 
> Why not defining wfi() for __LINUX_ARM_ARCH__ < 7 as it is done for dsb() and 
> friends in arch/arm/include/asm/barrier.h? So you can get rid of that #if 
> completly.

Well, Russell said it was not useful because "there's no architected WFI
instruction which doesn't have CPU specific issues (hence why we have
cpu_do_idle() to abstract that)"

-- 
Alexandre Belloni, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com