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  1. 20 1月, 2012 2 次提交
  3. 04 1月, 2012 2 次提交
  5. 22 12月, 2011 1 次提交
    • R
      PM: Run the driver callback directly if the subsystem one is not there · 35cd133c
      由 Rafael J. Wysocki 提交于 
      Make the PM core execute driver PM callbacks directly if the
corresponding subsystem callbacks are not present.

There are three reasons for doing that.  First, it reflects the
behavior of drivers/base/dd.c:really_probe() that runs the driver's
.probe() callback directly if the bus type's one is not defined, so
this change will remove one arbitrary difference between the PM core
and the remaining parts of the driver core.  Second, it will allow
some subsystems, whose PM callbacks don't do anything except for
executing driver callbacks, to be simplified quite a bit by removing
those "forward-only" callbacks.  Finally, it will allow us to remove
one level of indirection in the system suspend and resume code paths
where it is not necessary, which is going to lead to less debug noise
with initcall_debug passed in the kernel command line (messages won't
be printed for driverless devices whose subsystems don't provide
PM callbacks among other things).
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
      35cd133c
  7. 09 12月, 2011 1 次提交
  9. 06 12月, 2011 1 次提交
  11. 29 11月, 2011 4 次提交
  13. 22 11月, 2011 2 次提交
    • T
      freezer: unexport refrigerator() and update try_to_freeze() slightly · a0acae0e
      由 Tejun Heo 提交于 
      There is no reason to export two functions for entering the
refrigerator.  Calling refrigerator() instead of try_to_freeze()
doesn't save anything noticeable or removes any race condition.

* Rename refrigerator() to __refrigerator() and make it return bool
  indicating whether it scheduled out for freezing.

* Update try_to_freeze() to return bool and relay the return value of
  __refrigerator() if freezing().

* Convert all refrigerator() users to try_to_freeze().

* Update documentation accordingly.

* While at it, add might_sleep() to try_to_freeze().
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Christoph Hellwig <hch@infradead.org>
      a0acae0e
    • T
      freezer: don't unnecessarily set PF_NOFREEZE explicitly · 3a7cbd50
      由 Tejun Heo 提交于 
      Some drivers set PF_NOFREEZE in their kthread functions which is
completely unnecessary and racy - some part of freezer code doesn't
consider cases where PF_NOFREEZE is set asynchronous to freezer
operations.

In general, there's no reason to allow setting PF_NOFREEZE explicitly.
Remove them and change the documentation to note that setting
PF_NOFREEZE directly isn't allowed.

-v2: Dropped change to twl4030-irq.c as it no longer uses PF_NOFREEZE.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: N"Gustavo F. Padovan" <padovan@profusion.mobi>
Acked-by: NSamuel Ortiz <sameo@linux.intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: wwang <wei_wang@realsil.com.cn>
      3a7cbd50
  15. 05 11月, 2011 2 次提交
  17. 22 10月, 2011 1 次提交
  19. 17 10月, 2011 3 次提交
    • R
      PM / Hibernate: Freeze kernel threads after preallocating memory · 2aede851
      由 Rafael J. Wysocki 提交于 
      There is a problem with the current ordering of hibernate code which
leads to deadlocks in some filesystems' memory shrinkers.  Namely,
some filesystems use freezable kernel threads that are inactive when
the hibernate memory preallocation is carried out.  Those same
filesystems use memory shrinkers that may be triggered by the
hibernate memory preallocation.  If those memory shrinkers wait for
the frozen kernel threads, the hibernate process deadlocks (this
happens with XFS, for one example).

Apparently, it is not technically viable to redesign the filesystems
in question to avoid the situation described above, so the only
possible solution of this issue is to defer the freezing of kernel
threads until the hibernate memory preallocation is done, which is
implemented by this change.

Unfortunately, this requires the memory preallocation to be done
before the "prepare" stage of device freeze, so after this change the
only way drivers can allocate additional memory for their freeze
routines in a clean way is to use PM notifiers.
Reported-by: NChristoph <cr2005@u-club.de>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
      2aede851
    • A
      PM: Update the policy on default wakeup settings · 8f88893c
      由 Alan Stern 提交于 
      This patch (as1485) documents a change to the kernel's default wakeup
policy.  Devices that forward wakeup requests between buses should be
enabled for wakeup by default.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
      8f88893c
    • S
      PM / Suspend: Add statistics debugfs file for suspend to RAM · 2a77c46d
      由 ShuoX Liu 提交于 
      Record S3 failure time about each reason and the latest two failed
devices' names in S3 progress.
We can check it through 'suspend_stats' entry in debugfs.

The motivation of the patch:

We are enabling power features on Medfield. Comparing with PC/notebook,
a mobile enters/exits suspend-2-ram (we call it s3 on Medfield) far
more frequently. If it can't enter suspend-2-ram in time, the power
might be used up soon.

We often find sometimes, a device suspend fails. Then, system retries
s3 over and over again. As display is off, testers and developers
don't know what happens.

Some testers and developers complain they don't know if system
tries suspend-2-ram, and what device fails to suspend. They need
such info for a quick check. The patch adds suspend_stats under
debugfs for users to check suspend to RAM statistics quickly.

If not using this patch, we have other methods to get info about
what device fails. One is to turn on  CONFIG_PM_DEBUG, but users
would get too much info and testers need recompile the system.

In addition, dynamic debug is another good tool to dump debug info.
But it still doesn't match our utilization scenario closely.
1) user need write a user space parser to process the syslog output;
2) Our testing scenario is we leave the mobile for at least hours.
   Then, check its status. No serial console available during the
   testing. One is because console would be suspended, and the other
   is serial console connecting with spi or HSU devices would consume
   power. These devices are powered off at suspend-2-ram.
Signed-off-by: NShuoX Liu <shuox.liu@intel.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
      2a77c46d
  21. 11 10月, 2011 1 次提交
  23. 07 10月, 2011 2 次提交
  25. 05 10月, 2011 1 次提交
  27. 28 9月, 2011 1 次提交
    • P
      doc: fix broken references · 395cf969
      由 Paul Bolle 提交于 
      There are numerous broken references to Documentation files (in other
Documentation files, in comments, etc.). These broken references are
caused by typo's in the references, and by renames or removals of the
Documentation files. Some broken references are simply odd.

Fix these broken references, sometimes by dropping the irrelevant text
they were part of.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
      395cf969
  29. 22 9月, 2011 1 次提交
  31. 25 8月, 2011 1 次提交
  33. 14 8月, 2011 1 次提交
    • C
      PM / Runtime: Add might_sleep() to runtime PM functions · 311aab73
      由 Colin Cross 提交于 
      Some of the entry points to pm runtime are not safe to
call in atomic context unless pm_runtime_irq_safe() has
been called.  Inspecting the code, it is not immediately
obvious that the functions sleep at all, as they run
inside a spin_lock_irqsave, but under some conditions
they can drop the lock and turn on irqs.

If a driver incorrectly calls the pm_runtime apis, it can
cause sleeping and irq processing when it expects to stay
in atomic context.

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

Add pm_runtime_put_sync_autosuspend to the list of
functions that can be called in atomic context.
Signed-off-by: NColin Cross <ccross@android.com>
Reviewed-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
      311aab73
  35. 06 8月, 2011 1 次提交
    • K
      PM / Runtime: Allow _put_sync() from interrupts-disabled context · 02b26774
      由 Kevin Hilman 提交于 
      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: NColin Cross <ccross@google.com>
Tested-by: NNishanth Menon <nm@ti.com>
Signed-off-by: NKevin Hilman <khilman@ti.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
      02b26774
  37. 16 7月, 2011 1 次提交
  39. 12 7月, 2011 1 次提交
  41. 06 7月, 2011 3 次提交
    • R
      PM / Runtime: Replace "run-time" with "runtime" in documentation · 62052ab1
      由 Rafael J. Wysocki 提交于 
      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: NRafael J. Wysocki <rjw@sisk.pl>
      62052ab1
    • R
      PM / Runtime: Improve documentation of enable, disable and barrier · e358bad7
      由 Rafael J. Wysocki 提交于 
      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: NRafael J. Wysocki <rjw@sisk.pl>
      e358bad7
    • R
      PM: Limit race conditions between runtime PM and system sleep (v2) · 1e2ef05b
      由 Rafael J. Wysocki 提交于 
      One of the roles of the PM core is to prevent different PM callbacks
executed for the same device object from racing with each other.
Unfortunately, after commit e8665002
(PM: Allow pm_runtime_suspend() to succeed during system suspend)
runtime PM callbacks may be executed concurrently with system
suspend/resume callbacks for the same device.

The main reason for commit e8665002
was that some subsystems and device drivers wanted to use runtime PM
helpers, pm_runtime_suspend() and pm_runtime_put_sync() in
particular, for carrying out the suspend of devices in their
.suspend() callbacks.  However, as it's been determined recently,
there are multiple reasons not to do so, inlcuding:

 * The caller really doesn't control the runtime PM usage counters,
   because user space can access them through sysfs and effectively
   block runtime PM.  That means using pm_runtime_suspend() or
   pm_runtime_get_sync() to suspend devices during system suspend
   may or may not work.

 * If a driver calls pm_runtime_suspend() from its .suspend()
   callback, it causes the subsystem's .runtime_suspend() callback to
   be executed, which leads to the call sequence:

   subsys->suspend(dev)
      driver->suspend(dev)
         pm_runtime_suspend(dev)
            subsys->runtime_suspend(dev)

   recursive from the subsystem's point of view.  For some subsystems
   that may actually work (e.g. the platform bus type), but for some
   it will fail in a rather spectacular fashion (e.g. PCI).  In each
   case it means a layering violation.

 * Both the subsystem and the driver can provide .suspend_noirq()
   callbacks for system suspend that can do whatever the
   .runtime_suspend() callbacks do just fine, so it really isn't
   necessary to call pm_runtime_suspend() during system suspend.

 * The runtime PM's handling of wakeup devices is usually different
   from the system suspend's one, so .runtime_suspend() may simply be
   inappropriate for system suspend.

 * System suspend is supposed to work even if CONFIG_PM_RUNTIME is
   unset.

 * The runtime PM workqueue is frozen before system suspend, so if
   whatever the driver is going to do during system suspend depends
   on it, that simply won't work.

Still, there is a good reason to allow pm_runtime_resume() to
succeed during system suspend and resume (for instance, some
subsystems and device drivers may legitimately use it to ensure that
their devices are in full-power states before suspending them).
Moreover, there is no reason to prevent runtime PM callbacks from
being executed in parallel with the system suspend/resume .prepare()
and .complete() callbacks and the code removed by commit
e8665002 went too far in this
respect.  On the other hand, runtime PM callbacks, including
.runtime_resume(), must not be executed during system suspend's
"late" stage of suspending devices and during system resume's "early"
device resume stage.

Taking all of the above into consideration, make the PM core
acquire a runtime PM reference to every device and resume it if
there's a runtime PM resume request pending right before executing
the subsystem-level .suspend() callback for it.  Make the PM core
drop references to all devices right after executing the
subsystem-level .resume() callbacks for them.  Additionally,
make the PM core disable the runtime PM framework for all devices
during system suspend, after executing the subsystem-level .suspend()
callbacks for them, and enable the runtime PM framework for all
devices during system resume, right before executing the
subsystem-level .resume() callbacks for them.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NKevin Hilman <khilman@ti.com>
      1e2ef05b
  43. 02 7月, 2011 6 次提交
  45. 22 6月, 2011 1 次提交