On Mon, Jul 02, 2018 at 12:08:45PM -0700, Srinivas Pandruvada wrote: > From: Srinivas <srinivas.pandruv...@linux.intel.com> > > One of the requirement for modern x86 system to enter lowest power mode > (SLP_S0) is SATA IP block to be off. This is true even during when > platform is suspended to idle and not only in opportunistic (runtime) > suspend. > > Several of these system don't have traditional ACPI S3, so it is > important that they enter SLP_S0 state, to avoid draining battery even > during suspend even with out of the box Linux installation. > > SATA IP block doesn't get turned off till SATA is in DEVSLP mode. Here > user has to either use scsi-host sysfs or tools like powertop to set > the sata-host link_power_management_policy to min_power. > > This change sets by default link power management policy to min_power > for some platforms. To avoid regressions, the following conditions > are used: > - The kernel config is already set to use med_power_with_dipm or deeper > - System is a modern standby system using ACPI low power idle flag > - The platform is not blacklisted for Suspend to Idle and suspend > to idle is used instead of S3 > This combination will make sure that systems are fairly recent and > since getting shipped with modern standby standby, the DEVSLP function > is already validated. > > Signed-off-by: Srinivas Pandruvada <srinivas.pandruv...@linux.intel.com>
Seems sane to me. Hans, what do you think? Thanks. -- tejun
