[PATCH] ARM: OMAP2+: Only write the sysconfig on idle when necessary
jon-hunter at ti.com
Wed Oct 17 17:22:47 EDT 2012
On 10/17/2012 03:58 PM, Paul Walmsley wrote:
> On Wed, 17 Oct 2012, Jon Hunter wrote:
>> Are you looking to go one step further and only update the sysconfig on
>> enabling when the context has been lost? That would require more
> Yes that's exactly it. That would avoid adding a special case for what
> should be the common case. From a quick glance it looks like the cache
> needs to be loaded in _reset(), omap_hwmod_softreset(), and _enable().
> Other than that, seems like the cached value should work.
> It should also be possible to avoid the reload in _enable() in most cases
> since the PM code should know whether the IP block's powerdomain was
> programmed to go off and indeed whether it did so. It shouldn't involve
> any extra register reads. But I wouldn't expect you to add that
> optimization; would just be nice to have a comment to that effect.
Ah, so you really want the cache to behave like a cache. That would be nice!
> If the meta-theme of your message is that commit
> 233cbe5b94096f95ba7bca2162d63275b0b90b5b should have had closer scrutiny,
> I agree with you, but we're beyond that point now...
No under-lying theme here, just more of a "I stumbled across this while
debugging something else" and I am a nut-case about saving cpu cycles
where I can. Although not always possible and I am probably responsible
for burning more cycles than I am saving these days!
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