[SRU] [OEM-B] [PATCH 0/2] Use "Medium power with Device Initiated PM" as default LPM policy for mobile SATA devices

[Kai-Heng Feng]

BugLink: https://bugs.launchpad.net/bugs/1778029

[Impact]
Intel CPU can't reach beyond Package C-State 3 (PC3). Drains lots of power.

[Test]
Check the value of /sys/devices/pci0000:00/0000:00:17.0/ata1/host0/scsi_host/host0/link_power_management_policy.

It's med_power_with_dipm as default.
Also check the powertop, it can reach PC8.

[Fix]
Introduce a new config to let AHCI pick med_power_with_dipm for mobile platforms.

[Regression Potential]
Medium. Some SATA devices are broken under med_power_with_dipm or min_power.
Fortunately this is for -oem kernel only, so every SATA device gets tested before shipping to customers.

Hans de Goede (1):
  ahci: Allow setting a default LPM policy for mobile chipsets

Kai-Heng Feng (1):
  UBUNTU: Config: set CONFIG_SATA_MOBILE_LPM_POLICY to
    med_power_with_dipm

 debian.oem/config/config.common.ubuntu |  1 +
 drivers/ata/Kconfig                    | 19 +++++
 drivers/ata/ahci.c                     | 97 +++++++++++++++-----------
 drivers/ata/ahci.h                     |  3 +
 4 files changed, 79 insertions(+), 41 deletions(-)

-- 
2.17.0