Messages in this thread | | | Date | Fri, 19 Aug 2011 15:26:38 -0400 | From | Nick Bowler <> | Subject | Re: [PATCH RFC] ARM: vexpress: Use assembler mnemonic for WFI in platform_do_lowpower. |
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On 2011-08-19 19:15 +0100, Jamie Iles wrote: > On Fri, Aug 19, 2011 at 02:03:24PM -0400, Nick Bowler wrote: [...] > > - /* > > - * here's the WFI > > - */ > > - asm(".word 0xe320f003\n" > > + asm("wfi\n" > > : > > : > > : "memory", "cc"); > > There's a wfi() macro defined in arch/arm/include/asm/system.h that > could be used here.
Indeed, thanks for pointing that out.
I'm a little wary, however: the wfi macro does not include the "cc" clobber that this code has currently, and I don't know what the implications of removing it are. There appears to be no current users of the wfi macro.
Taking a closer look, there appear to be five platforms that have a hardcoded WFI just like the above (including the "cc" clobber): exynos4, realview, shmobile, tegra and vexpress. omap defines its own do_wfi macro, *without* the "cc" clobber.
Nevertheless, using the macro seems to work just fine, so I can certainly re-spin the patch with that instead.
-- Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)
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