linux-stable.git/include/linux/pm_domain.h, branch v3.18.76

PM / Domains: Fix initial default state of the need_restore flag

2014-11-11T21:28:44+00:00

The initial state of the device's need_restore flag should'nt depend on
the current state of the PM domain. For example it should be perfectly
valid to attach an inactive device to a powered PM domain.

The pm_genpd_dev_need_restore() API allow us to update the need_restore
flag to somewhat cope with such scenarios. Typically that should have
been done from drivers/buses ->probe() since it's those that put the
requirements on the value of the need_restore flag.

Until recently, the Exynos SOCs were the only user of the
pm_genpd_dev_need_restore() API, though invoking it from a centralized
location while adding devices to their PM domains.

Due to that Exynos now have swithed to the generic OF-based PM domain
look-up, it's no longer possible to invoke the API from a centralized
location. The reason is because devices are now added to their PM
domains during the probe sequence.

Commit "ARM: exynos: Move to generic PM domain DT bindings"
did the switch for Exynos to the generic OF-based PM domain look-up,
but it also removed the call to pm_genpd_dev_need_restore(). This
caused a regression for some of the Exynos drivers.

To handle things more properly in the generic PM domain, let's change
the default initial value of the need_restore flag to reflect that the
state is unknown. As soon as some of the runtime PM callbacks gets
invoked, update the initial value accordingly.

Moreover, since the generic PM domain is verifying that all devices
are both runtime PM enabled and suspended, using pm_runtime_suspended()
while pm_genpd_poweroff() is invoked from the scheduled work, we can be
sure of that the PM domain won't be powering off while having active
devices.

Do note that, the generic PM domain can still only know about active
devices which has been activated through invoking its runtime PM resume
callback. In other words, buses/drivers using pm_runtime_set_active()
during ->probe() will still suffer from a race condition, potentially
probing a device without having its PM domain being powered. That issue
will have to be solved using a different approach.

This a log from the boot regression for Exynos5, which is being fixed in
this patch.

------------[ cut here ]------------
WARNING: CPU: 0 PID: 308 at ../drivers/clk/clk.c:851 clk_disable+0x24/0x30()
Modules linked in:
CPU: 0 PID: 308 Comm: kworker/0:1 Not tainted 3.18.0-rc3-00569-gbd9449f-dirty #10
Workqueue: pm pm_runtime_work
[] (unwind_backtrace) from [] (show_stack+0x10/0x14)
[] (show_stack) from [] (dump_stack+0x70/0xbc)
[] (dump_stack) from [] (warn_slowpath_common+0x64/0x88)
[] (warn_slowpath_common) from [] (warn_slowpath_null+0x1c/0x24)
[] (warn_slowpath_null) from [] (clk_disable+0x24/0x30)
[] (clk_disable) from [] (gsc_runtime_suspend+0x128/0x160)
[] (gsc_runtime_suspend) from [] (pm_generic_runtime_suspend+0x2c/0x38)
[] (pm_generic_runtime_suspend) from [] (pm_genpd_default_save_state+0x2c/0x8c)
[] (pm_genpd_default_save_state) from [] (pm_genpd_poweroff+0x224/0x3ec)
[] (pm_genpd_poweroff) from [] (pm_genpd_runtime_suspend+0x9c/0xcc)
[] (pm_genpd_runtime_suspend) from [] (__rpm_callback+0x2c/0x60)
[] (__rpm_callback) from [] (rpm_callback+0x20/0x74)
[] (rpm_callback) from [] (rpm_suspend+0xd4/0x43c)
[] (rpm_suspend) from [] (pm_runtime_work+0x80/0x90)
[] (pm_runtime_work) from [] (process_one_work+0x12c/0x314)
[] (process_one_work) from [] (worker_thread+0x3c/0x4b0)
[] (worker_thread) from [] (kthread+0xcc/0xe8)
[] (kthread) from [] (ret_from_fork+0x14/0x3c)
---[ end trace 40cd58bcd6988f12 ]---

Fixes: a4a8c2c4962bb655 (ARM: exynos: Move to generic PM domain DT bindings)
Reported-and-tested0by: Sylwester Nawrocki 
Reviewed-by: Sylwester Nawrocki 
Reviewed-by: Kevin Hilman 
Signed-off-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Change prototype for the attach and detach callbacks

2014-11-08T01:23:21+00:00

Convert the prototypes to return an int in order to support error
handling in these callbacks.

Also, as suggested by Dmitry Torokhov, pass the domain pointer for use
inside the callbacks, and so that they match the existing
power_on/power_off callbacks which currently take the domain pointer.

Acked-by: Dmitry Torokhov 
Acked-by: Geert Uytterhoeven 
Signed-off-by: Ulf Hansson 
[ khilman: added domain as parameter to callbacks, as suggested by Dmitry ]
Signed-off-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Rename cpu_data to cpuidle_data

2014-10-03T13:43:14+00:00

The "cpu_data" are defined for some archs and thus conflicting with the
"cpu_data" member in the struct gpd_cpu_data. This causes a compiler
error for those archs.

Let's fix it by rename the member to cpuidle_data. In this context it
also seems appropriate to rename the struct to gpd_cpuidle_data to
better reflect its use.

Fixes: f48c767ce895 (PM / Domains: Move dev_pm_domain_attach|detach() to pm_domain.h)
Signed-off-by: Ulf Hansson 
Acked-by: Geert Uytterhoeven 
Acked-by: Pavel Machek 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Move dev_pm_domain_attach|detach() to pm_domain.h

2014-09-29T23:16:44+00:00

The commit 46420dd73b80 (PM / Domains: Add APIs to attach/detach a PM
domain for a device) started using errno values in pm.h header file.
It also failed to include the header for these, thus it caused
compiler errors.

Instead of including the errno header to pm.h, let's move the functions
to pm_domain.h, since it's a better match.

Fixes: 46420dd73b80 (PM / Domains: Add APIs to attach/detach a PM domain for a device)
Signed-off-by: Ulf Hansson 
Acked-by: Geert Uytterhoeven 
Acked-by: Wolfram Sang 
Acked-by: Mark Brown 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Remove legacy API for adding devices through DT

2014-09-25T20:13:42+00:00

There are no active clients of the legacy API and we now also have a
better way to handle genpd DT support. So let's remove the legacy API.

Signed-off-by: Ulf Hansson 
Acked-by: Geert Uytterhoeven 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Add genpd attach/detach callbacks

2014-09-25T20:08:41+00:00

While a PM domain can enable PM runtime management of its devices' module
clocks by setting

	genpd->dev_ops.stop = pm_clk_suspend;
	genpd->dev_ops.start = pm_clk_resume;

this also requires registering the clocks with the pm_clk subsystem.
In the legacy case, this is handled by the platform code, after
attaching the device to its PM domain.

When the devices are instantiated from DT, devices are attached to their
PM domains by generic code, leaving no method for the platform-specific
PM domain code to register their clocks.

Add two callbacks, allowing a PM domain to perform platform-specific
tasks when a device is attached to or detached from a PM domain.

Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Ulf Hansson 
Signed-off-by: Rafael J. Wysocki

PM / Domains: Add generic OF-based PM domain look-up

2014-09-22T13:57:40+00:00

This patch introduces generic code to perform PM domain look-up using
device tree and automatically bind devices to their PM domains.

Generic device tree bindings are introduced to specify PM domains of
devices in their device tree nodes.

Backwards compatibility with legacy Samsung-specific PM domain bindings
is provided, but for now the new code is not compiled when
CONFIG_ARCH_EXYNOS is selected to avoid collision with legacy code.
This will change as soon as the Exynos PM domain code gets converted to
use the generic framework in further patch.

This patch was originally submitted by Tomasz Figa when he was employed
by Samsung.

Link: http://marc.info/?l=linux-pm&m=139955349702152&w=2
Signed-off-by: Ulf Hansson 
Acked-by: Rob Herring 
Tested-by: Philipp Zabel 
Reviewed-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / domains: Keep declaration of dev_power_governors together

2014-09-08T22:46:13+00:00

This is a pure code cleanup in the header file for the PM domain. No
functional change.

Signed-off-by: Ulf Hansson 
Reviewed-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / domains: Remove default_stop_ok() API

2014-09-08T22:46:13+00:00

There are currently no need to export default_stop_ok() as an API,
instead let's keep it local to the PM domain governor.

Signed-off-by: Ulf Hansson 
Reviewed-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / domains: Remove genpd_queue_power_off_work() API

2014-09-08T22:46:12+00:00

There are no active users of this API. Let's remove it and if future
needs shows up we could consider to have a get/put API instead.

Signed-off-by: Ulf Hansson 
Reviewed-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki