linux-toradex.git/Documentation/power, branch tegra

PM: runtime: add might_sleep to PM runtime functions

2011-12-01T05:39:08+00:00

The list of functions that can be called in atomic context is
non-intuitive (pm_runtime_put_sync can not, but
pm_runtime_put_sync_suspend can, if pm_runtime_irq_safe has
been called?).  The code is actively misleading - the entry
points all start with spin_lock_irqsave, suggesting they
are safe to call in atomic context, but may later
enable interrupts.

Add might_sleep_if to all the __pm_runtime_* entry points
to enforce correct usage.

Also add pm_runtime_put_sync_autosuspend to the list of
functions that can be called in atomic context.

Change-Id: Icac17a10d77c64d44bd2761a91a588dfd1d0c6f0
Signed-off-by: Colin Cross

PM / Runtime: Automatically retry failed autosuspends

2011-11-11T17:44:11+00:00

commit 886486b792e4f6f96d4fbe8ec5bf20811cab7d6a upstream.

Originally, the runtime PM core would send an idle notification
whenever a suspend attempt failed.  The idle callback routine could
then schedule a delayed suspend for some time later.

However this behavior was changed by commit
f71648d73c1650b8b4aceb3856bebbde6daa3b86 (PM / Runtime: Remove idle
notification after failing suspend).  No notifications were sent, and
there was no clear mechanism to retry failed suspends.

This caused problems for the usbhid driver, because it fails
autosuspend attempts as long as a key is being held down.  Therefore
this patch (as1492) adds a mechanism for retrying failed
autosuspends.  If the callback routine updates the last_busy field so
that the next autosuspend expiration time is in the future, the
autosuspend will automatically be rescheduled.

Signed-off-by: Alan Stern 
Tested-by: Henrik Rydberg 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

PM / Runtime: Correct documentation of pm_runtime_irq_safe()

2011-08-25T13:31:05+00:00

The description of pm_runtime_irq_safe() has to be updated to follow
the code after commit 02b2677 (PM / Runtime: Allow _put_sync() from
interrupts-disabled context).

Signed-off-by: Rafael J. Wysocki 
Acked-by: Kevin Hilman

PM / Runtime: Allow _put_sync() from interrupts-disabled context

2011-08-05T19:45:20+00:00

Currently the use of pm_runtime_put_sync() is not safe from
interrupts-disabled context because rpm_idle() will release the
spinlock and enable interrupts for the idle callbacks.  This enables
interrupts during a time where interrupts were expected to be
disabled, and can have strange side effects on drivers that expected
interrupts to be disabled.

This is not a bug since the documentation clearly states that only
_put_sync_suspend() is safe in IRQ-safe mode.

However, pm_runtime_put_sync() could be made safe when in IRQ-safe
mode by releasing the spinlock but not re-enabling interrupts, which
is what this patch aims to do.

Problem was found when using some buggy drivers that set
pm_runtime_irq_safe() and used _put_sync() in interrupts-disabled
context.

Reported-by: Colin Cross 
Tested-by: Nishanth Menon 
Signed-off-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

Merge branch 'pm-runtime' into for-linus

2011-07-15T21:59:25+00:00

* pm-runtime:
  OMAP: PM: disable idle on suspend for GPIO and UART
  OMAP: PM: omap_device: add API to disable idle on suspend
  OMAP: PM: omap_device: add system PM methods for PM domain handling
  OMAP: PM: omap_device: conditionally use PM domain runtime helpers
  PM / Runtime: Add new helper function: pm_runtime_status_suspended()
  PM / Runtime: Consistent utilization of deferred_resume
  PM / Runtime: Prevent runtime_resume from racing with probe
  PM / Runtime: Replace "run-time" with "runtime" in documentation
  PM / Runtime: Improve documentation of enable, disable and barrier
  PM: Limit race conditions between runtime PM and system sleep (v2)
  PCI / PM: Detect early wakeup in pci_pm_prepare()
  PM / Runtime: Return special error code if runtime PM is disabled
  PM / Runtime: Update documentation of interactions with system sleep

Merge branch 'pm-domains' into for-linus

2011-07-15T21:59:09+00:00

* pm-domains: (33 commits)
  ARM / shmobile: Return -EBUSY from A4LC power off if A3RV is active
  PM / Domains: Take .power_off() error code into account
  ARM / shmobile: Use genpd_queue_power_off_work()
  ARM / shmobile: Use pm_genpd_poweroff_unused()
  PM / Domains: Introduce function to power off all unused PM domains
  PM / Domains: Queue up power off work only if it is not pending
  PM / Domains: Improve handling of wakeup devices during system suspend
  PM / Domains: Do not restore all devices on power off error
  PM / Domains: Allow callbacks to execute all runtime PM helpers
  PM / Domains: Do not execute device callbacks under locks
  PM / Domains: Make failing pm_genpd_prepare() clean up properly
  PM / Domains: Set device state to "active" during system resume
  ARM: mach-shmobile: sh7372 A3RV requires A4LC
  PM / Domains: Export pm_genpd_poweron() in header
  ARM: mach-shmobile: sh7372 late pm domain off
  ARM: mach-shmobile: Runtime PM late init callback
  ARM: mach-shmobile: sh7372 D4 support
  ARM: mach-shmobile: sh7372 A4MP support
  ARM: mach-shmobile: sh7372: make sure that fsi is peripheral of spu2
  ARM: mach-shmobile: sh7372 A3SG support
  ...

PM / OPP: Introduce function to free cpufreq table

2011-07-15T21:58:18+00:00

cpufreq table allocated by opp_init_cpufreq_table is better
freed by OPP layer itself. This allows future modifications to
the table handling to be transparent to the users.

Signed-off-by: Nishanth Menon 
Acked-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / Runtime: Add new helper function: pm_runtime_status_suspended()

2011-07-12T09:17:09+00:00

This boolean function simply returns whether or not the runtime status
of the device is 'suspended'.  Unlike pm_runtime_suspended(), this
function returns the runtime status whether or not runtime PM for the
device has been disabled or not.

Also add entry to Documentation/power/runtime.txt

Signed-off-by: Kevin Hilman 
Signed-off-by: Rafael J. Wysocki

PM / Runtime: Replace "run-time" with "runtime" in documentation

2011-07-06T08:52:13+00:00

The runtime PM documentation and kerneldoc comments sometimes spell
"runtime" with a dash (i.e. "run-time").  Replace all of those
instances with "runtime" to make the naming consistent.

Signed-off-by: Rafael J. Wysocki

PM / Runtime: Improve documentation of enable, disable and barrier

2011-07-06T08:52:06+00:00

The runtime PM documentation in Documentation/power/runtime_pm.txt
doesn't say that pm_runtime_enable() and pm_runtime_disable() work by
operating on power.disable_depth, which is wrong, because the
possibility of nesting disables doesn't follow from the description
of these functions.  Also, there is no description of
pm_runtime_barrier() at all in the document, which is confusing.
Improve the documentation by fixing those issues.

Signed-off-by: Rafael J. Wysocki