[PATCH v3 0/8] PM / ACPI / i2c: Deploy runtime PM centric path for system sleep

[ulf.hansson@linaro.org (Ulf Hansson)]

The i2c designware platform driver, drivers/i2c/busses/i2c-designware-platdrv.c,
isn't well optimized for system sleep.

What makes this driver particularly interesting is because it's a cross-SoC
driver, which sometimes means there is an ACPI PM domain attached to the i2c
device and sometimes not. The driver is being used on both x86 and ARM.

In principle, to optimize the system sleep support in i2c driver, this series
enables the proven runtime PM centric path for the i2c driver. However, to do
that the ACPI PM domain also have to collaborate and understand this behaviour.
>From earlier versions, Rafael has also pointed out that also the PM core needs
to be involved.

Therefore a number of changes, patch 1 to patch 6, makes the needed changes to
the PM core and the ACPI PM domain. In patch7 and patch 8, the i2c driver gets
optimized and is converted to the runtime PM centric path for system sleep.

It shall be noted, the behaviour of the ACPI PM domain should remain intact,
still taking benefit of using the direct_complete path during system sleep,
except for those drivers that uses the runtime PM centric path.

This series has been tested on an ARM64 Hikey board, which isn't having the
i2c device attached to the ACPI PM domain. This means that the ACPI changes
needs to be tested on some relevant Intel SoCs and it's greatly appreciated
is someone could help out with this, so is of course review comments.

Some news in v3:
	- The fix for the i2c driver [1], is now present in Linus' tree from tag
	v4.13-rc7 - and so does Rafael's tree.
	- To simplify for testers, I have published a branch [3] based upon
	Rafael's pm tree and linux-next branch.
	- Rephrased some part of the coverletter to clarify the intent of this
	series.
	- Addressed review comments from v2.

Some news in v2:
	- The v1 contained a fix for the i2c driver, this has been sent
	separately [1] and picked up for fixes by Wolfram for v4.13-rcs. However
	the fix has not yet reached Linus' tree. The changes on i2c driver
	are based upon that change.
	- To simplify for testers, I have published a branch [2] based upon
	Rafael's pm tree and linux-next branch, which also includes the above
	patch.
	- Rephrased the coverletter to clarify the intent of this series.
	- Addressed review comments from v1.

[1]
http://patchwork.ozlabs.org/patch/799803/

[2]
git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc.git acpi_pm_i2c_rpm_path_v2

[3]
git://git.kernel.org/pub/scm/linux/kernel/git/ulfh/mmc.git acpi_pm_i2c_rpm_path_v3

Kind regards
Ulf Hansson


Ulf Hansson (8):
  PM / Sleep: Make the runtime PM centric path known to the PM core
  PM / ACPI: Restore acpi_subsys_complete()
  PM / Sleep: Remove pm_complete_with_resume_check()
  PM / ACPI: Split code validating need for runtime resume in
    ->prepare()
  PM / ACPI: Split acpi_lpss_suspend_late|resume_early()
  PM / ACPI: Enable the runtime PM centric approach for system sleep
  i2c: designware: Don't resume device in the ->complete() callback
  i2c: designware: Deploy the runtime PM centric path for system sleep

 drivers/acpi/acpi_lpss.c                    |  79 ++++++++++++++------
 drivers/acpi/device_pm.c                    | 111 ++++++++++++++++++++++------
 drivers/base/power/generic_ops.c            |  23 ------
 drivers/base/power/main.c                   |  49 ++++++++++--
 drivers/base/power/runtime.c                |   1 +
 drivers/i2c/busses/i2c-designware-platdrv.c |  34 ++-------
 include/linux/pm.h                          |   8 +-
 7 files changed, 204 insertions(+), 101 deletions(-)

-- 
2.7.4