Hi James,

On Tue, Feb 09, 2010 at 21:51:01, James Nuss wrote:
> Hi,
>
> I have discovered a bug in the cpuidle code for the OMAP-L13x (da8xx)
> platform.
>
> In the state described as "WFI and DDR Self-Refresh", the code is
> actually putting the DDR into the "Power Down" mode which is not the
> same as self-refresh.
>
> So the description string should read "WFI and DDR Power Down".

Yes, going into power down on OMAP-L138 was intentional (it is
supposed to save more power than self-refresh). I agree the state
description could have been conditional on pdata->ddr2_pdown value.

>
> Putting the DDR into self-refresh and subsequently gating the clocks for
>   greater power savings, requires significantly  more work (Refer to
> Section 2.16 OMAP-L1x DDR2/mDDR Memory Controller User's Guide).

This is implemented as part of suspend-to-RAM support. Have a look at
arch/arm/mach-davinci/pm.c file.

Thanks,
Sekhar

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