APPLIED[B/C]: [PATCH 0/4][SRU][B][C][OEM-B]SATA device is not going to DEVSLP

[Kleber Souza]

On 11/28/18 10:19 AM, AceLan Kao wrote:
> BugLink: https://bugs.launchpad.net/bugs/1781533
>
> [Impact]
> Any of the platforms we’ve been seeing SATA problems not going to deepest
> state leads to other devices not getting there during long idle or s2idle.
> And it also prevents the system from entering deeper PC state other than
> PC3.
>
> [Fix]
> Suggested from Intel and Dell to contains the following 4 commits,
> and all of 4 commits are in v4.19-rc1
> https://patchwork.kernel.org/patch/10502285/
> https://patchwork.kernel.org/patch/10502287/
> https://patchwork.kernel.org/patch/10535781/
> https://patchwork.kernel.org/patch/10535783/
>
> [Test]
> Verified the power consumption on some new platforms, it improves the
> SATA HDD power consumption around 0.5w during long idle.
>
> [Regression Potential]
> Low, the DEVSLP function is already validated when shipped with SLP_S0
> support.
>
> Srinivas Pandruvada (4):
>   ata: ahci: Support state with min power but Partial low power state
>   ata: ahci: Enable DEVSLP by default on x86 with SLP_S0
>   ata: libahci: Correct setting of DEVSLP register
>   ata: libahci: Allow reconfigure of DEVSLP register
>
>  drivers/ata/ahci.c        | 38 +++++++++++++++++++++++++++++++++-----
>  drivers/ata/libahci.c     | 25 ++++++++++++++++---------
>  drivers/ata/libata-core.c |  1 +
>  drivers/ata/libata-scsi.c |  1 +
>  include/linux/libata.h    |  3 ++-
>  5 files changed, 53 insertions(+), 15 deletions(-)
>
Applied to bionic/master-next and cosmic/master-next branches.

As Stefan mentioned, a new commit to set the default
CONFIG_SATA_MOBILE_LPM_POLICY=0 on
debian.master/config/config.common.ubuntu was needed.

The Cosmic common config already had an entry for that, but set to =3.
That was set as requested on LP: #1759547 ("Use med_power_with_dipm SATA
LPM to save more power for mobile platforms"), if that default value
would also make more sense than =0 on Bionic please let us know.


Thanks,
Kleber