lkml.org 
[lkml]   [2016]   [Dec]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
Subject[PATCH v3 0/7] Runtime PM for Thunderbolt on Macs
Power down Thunderbolt controllers on Macs when nothing is plugged in
to save around 2W per controller.

Apple provides an ACPI-based (but nonstandard) mechanism to cut power
and signal hotplug during powerdown. The usual way to implement such
nonstandard mechanisms seems to be a struct dev_pm_domain.
E.g. vga_switcheroo uses that for Optimus GPUs which control power
with ACPI DSMs. Hence this third iteration of the series uses that
as well. In v2 a more complicated approach was employed wherein power
control was exerted by a PCIe port service driver instead.

All the prep work went into 4.9 and 4.10, shrinking this series to just
7 patches:

- The actual "meat" of the series (to borrow a term from Bjorn) is in
patches [6/7] and [7/7]. These two need an ack from Andreas.

- Patches [1/7] to [3/7] need an ack from Bjorn (and possibly Rafael or
Mika). They're fairly small and just add a bit to struct pci_dev
signifying that a device is part of a Thunderbolt daisy chain, then
use that bit to modify runtime PM for PCIe ports. I'm also cc'ing
Tomas and Amir at Intel Israel, if you guys have comments please shout.

- Patches [4/7] and [5/7] need an ack from Rafael. Their sole purpose
is to avoid a gratuitous WARN splat when assigning the struct
dev_pm_domain.

I've pushed the patches to GitHub to ease reviewing/fetching:
https://github.com/l1k/linux/commits/thunderbolt_runpm_v3

Link to the previous iteration (v2, May 2016):
http://www.spinics.net/lists/linux-pci/msg51158.html

Thanks,

Lukas


Lukas Wunner (7):
PCI: Recognize Thunderbolt devices
PCI: Allow runtime PM on Thunderbolt ports
PCI: Don't block runtime PM for Thunderbolt host hotplug ports
Revert "PM / Runtime: Remove the exported function
pm_children_suspended()"
PM: Make requirements of dev_pm_domain_set() more precise
thunderbolt: Power down controller when idle
thunderbolt: Runtime suspend NHI when idle

drivers/base/power/common.c | 15 +-
drivers/base/power/runtime.c | 3 +-
drivers/pci/pci.c | 20 ++-
drivers/pci/pci.h | 2 +
drivers/pci/probe.c | 34 +++++
drivers/thunderbolt/Kconfig | 3 +-
drivers/thunderbolt/Makefile | 4 +-
drivers/thunderbolt/nhi.c | 5 +
drivers/thunderbolt/power.c | 356 +++++++++++++++++++++++++++++++++++++++++++
drivers/thunderbolt/power.h | 37 +++++
drivers/thunderbolt/switch.c | 9 ++
drivers/thunderbolt/tb.c | 13 ++
drivers/thunderbolt/tb.h | 2 +
include/linux/pci.h | 1 +
include/linux/pm_runtime.h | 7 +
15 files changed, 500 insertions(+), 11 deletions(-)
create mode 100644 drivers/thunderbolt/power.c
create mode 100644 drivers/thunderbolt/power.h

--
2.10.2

\
 
 \ /
  Last update: 2016-12-17 15:40    [W:0.101 / U:0.912 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site