Re: [PATCH 4/5] ARM: scu: Move register defines to header file

Russell King - ARM Linux
2011-01-25T13:41:49Z

On Tue, Jan 25, 2011 at 06:06:27PM +0530, Santosh Shilimkar wrote:
> Ok. I missed some information my last email.
> The SCU power status programming is used to take CPU in/out
> of coherency as an alternative to SMP bit. We don't
> have an access to SMP bit on OMAP4. ARM has already
> confirmed SCU programming is same as SMP bit enable/disable.
>
> I don't know how safe is to use spin lock when one CPU is
> goes out of coherency after programming the power state. The
> spin lock release may not even be visible to other CPU.
> The programming happens from IDLE or suspend where the

BTW, presumably we should be flushing the caches/tlbs before setting
the CPU power register to a non-normal setting?

I'll wait until there's more information available (such as an example
implementation.)