Re: [patch 3/3] Enable Aggressive Link Power management for AHCI controllers.

[Jeff Garzik <jeff@garzik.org>]

Kristen Carlson Accardi wrote:
> This patch will set the correct bits to turn on Aggressive
> Link Power Management (ALPM) for the ahci driver.  This
> will cause the controller and disk to negotiate a lower
> power state for the link when there is no activity (see
> the AHCI 1.x spec for details).  This feature is mutually
> exclusive with Hot Plug, so when ALPM is enabled, Hot Plug
> is disabled.  ALPM will be enabled by default, but it is
> settable via the scsi host syfs interface.  Possible 
> settings for this feature are:
>
> Setting		Effect
> ----------------------------------------------------------
> min_power	ALPM is enabled, and link set to enter 
> 		lowest power state (SLUMBER) when idle
> 		Hot plug not allowed.
>
> max_performance	ALPM is disabled, Hot Plug is allowed
>
> medium_power	ALPM is enabled, and link set to enter
> 		second lowest power state (PARTIAL) when
> 		idle.  Hot plug not allowed.
>
> Signed-off-by:  Kristen Carlson Accardi <kristen.c.accardi@intel.com>

seems OK at first glance, though I'll have questions about hardware 
behavior once I get off this day-long Intel conference call :)


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