ACK: [SRU] [OEM-B] [PATCH 0/2] Use "Medium power with Device Initiated PM" as default LPM policy for mobile SATA devices
Anthony Wong
anthony.wong at canonical.com
Fri Jun 22 13:27:40 UTC 2018
On Fri, Jun 22, 2018 at 09:21:10PM +0800, Anthony Wong wrote:
> On Thu, Jun 21, 2018 at 05:59:16PM +0800, Kai-Heng Feng wrote:
> > 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
>
> Looks good, med_power_with_dipm has gone through some testing in the
> public lately, and as it is for linux-oem only the scope is limited
> and we can catch any side-effects in our QA process.
>
> Signed-off-by: Anthony Wong <anthony.wong at canonical.com>
Actually meant to be
Acked-by: Anthony Wong <anthony.wong at canonical.com>
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