linux-toradex.git/drivers/base/power, branch v3.18-rc5

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 / Sleep: fix async suspend_late/freeze_late error handling

2014-10-27T17:42:26+00:00

If an asynchronous suspend_late or freeze_late callback fails
during the SUSPEND, FREEZE or QUIESCE phases, we don't propagate the
corresponding error correctly, in effect ignoring the error and
continuing the suspend-to-ram/hibernation. During suspend-to-ram this
could leave some devices without a valid saved context, leading to a
failure to reinitialize them during resume. During hibernation this
could leave some devices active interfeering with the creation /
restoration of the hibernation image. Also this could leave the
corresponding devices without a valid saved context and failure to
reinitialize them during resume.

Fixes: de377b397272 (PM / sleep: Asynchronous threads for suspend_late)
Signed-off-by: Imre Deak 
Cc: 3.15+  # 3.15+
Signed-off-by: Rafael J. Wysocki

Merge branch 'pm-clk'

2014-10-06T23:18:58+00:00

* pm-clk:
  PM / clk: Fix crash in clocks management code if !CONFIG_PM_RUNTIME

Merge branch 'pm-domains'

2014-10-06T23:18:12+00:00

* pm-domains: (32 commits)
  PM / Domains: Rename cpu_data to cpuidle_data
  PM / Domains: Move dev_pm_domain_attach|detach() to pm_domain.h
  PM / Domains: Remove legacy API for adding devices through DT
  PM / Domains: Add genpd attach/detach callbacks
  PM / Domains: add debugfs listing of struct generic_pm_domain-s
  ACPI / PM: Convert acpi_dev_pm_detach() into a static function
  ARM: exynos: Move to generic PM domain DT bindings
  amba: Add support for attach/detach of PM domains
  spi: core: Convert to dev_pm_domain_attach|detach()
  mmc: sdio: Convert to dev_pm_domain_attach|detach()
  i2c: core: Convert to dev_pm_domain_attach|detach()
  drivercore / platform: Convert to dev_pm_domain_attach|detach()
  PM / Domains: Add APIs to attach/detach a PM domain for a device
  PM / Domains: Add generic OF-based PM domain look-up
  ACPI / PM: Assign the ->detach() callback when attaching the PM domain
  PM / Domains: Add a detach callback to the struct dev_pm_domain
  PM / domains: Spelling s/domian/domain/
  PM / domains: Keep declaration of dev_power_governors together
  PM / domains: Remove default_stop_ok() API
  drivers: sh: Leave disabling of unused PM domains to genpd
  ...

PM / clk: Fix crash in clocks management code if !CONFIG_PM_RUNTIME

2014-10-03T13:51:39+00:00

Unlike the clocks management code for runtime PM, the code used for
system suspend does not check the pm_clock_entry.status field.
If pm_clk_acquire() failed, ce->status will be PCE_STATUS_ERROR, and
ce->clk will be a negative error code (e.g. 0xfffffffe = -2 = -ENOENT).

Depending on the clock implementation, suspend or resume may crash with:

    Unable to handle kernel NULL pointer dereference at virtual address 00000026

(CCF clk_disable() has an IS_ERR_OR_NULL() check, while CCF clk_enable()
 only has a NULL check; pre-CCF implementations may behave differently)

While just checking for PCE_STATUS_ERROR would be sufficient, it doesn't
hurt to use the same state machine as is done for runtime PM, as this
makes the two versions more similar, and eligible for a future
consolidation.

Signed-off-by: Geert Uytterhoeven 
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 / sleep: Export dpm_suspend_late/noirq() and dpm_resume_early/noirq()

2014-09-30T19:05:59+00:00

Subsequent change sets will add platform-related operations between
dpm_suspend_late() and dpm_suspend_noirq() as well as between
dpm_resume_noirq() and dpm_resume_early() in suspend_enter(), so
export these functions for suspend_enter() to be able to call them
separately and split the invocations of dpm_suspend_end() and
dpm_resume_start() in there accordingly.

Signed-off-by: Rafael J. Wysocki

Merge branch 'pm-genirq' into acpi-pm

2014-09-30T18:46:13+00:00

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