Re: [PATCH 0/7] Runtime PM support for AHCI host controller driver
From: Tejun Heo
Date: Fri Feb 19 2016 - 10:54:21 EST
On Thu, Feb 18, 2016 at 10:54:10AM +0200, Mika Westerberg wrote:
> Linux already supports runtime PM of disks (drivers/scsi/sd.c) so that
> after certain amount of idle time the disk is suspended automatically. This
> series extends the support to AHCI host controllers. Whenever SATA ports
> are determined to be idle (all children are runtime suspended) the host
> controller is also suspended.
>
> On recent Intel CPUs like Broxton this allows the CPU to go low power idle
> states like S0ix runtime (given that all necessary blocks are also in their
> correesponding low power states).
>
> Patches [1-2/7] fix a lockup where disk is runtime suspended and the system
> is put to sleep. They are independent of the rest of the series.
>
> Patch [3/7] makes it possible for SATA ports to be runtime suspended when
> there is not disk connected. For example on Lenovo Yoga 900 there are two
> SATA ports which only one of them has disk connected. This patch allows the
> host controller to runtime suspend whenever the disk is idle.
Applied to libata/for-4.6.
Thanks.
--
tejun