Messages in this thread | | | Date | Mon, 16 Sep 2013 17:38:12 +0300 | From | Mika Westerberg <> | Subject | Re: [PATCH v2 1/9] i2c: prepare runtime PM support for I2C client devices |
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On Mon, Sep 16, 2013 at 11:12:49AM +0100, Mark Brown wrote: > That's definitely an ACPI specific (probably x86 specific ACPI?) > requirement not a generic one, on some systems it would increase power > consumption since the controller will need to sit on while the device is > functioning autonomously.
Yes, the ACPI 5.0 spec says that the device cannot be in higher D-state than its parent. This is not x86 specific, though I'm not sure if this is implemented elsewhere.
> Even though the controller power consumption is going to be minimal the > power domain it is in may be relatively large. Can't the power domains > for ACPI deal with this requirement, for example by making the I2C slave > power domains children of the controller power domain?
We'll look into this. Thanks for the suggestion.
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