summary refs log tree commit diff
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2013-11-20 13:25:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-20 13:25:04 -0800
commit82023bb7f75b0052f40d3e74169d191c3e4e6286 (patch)
tree06ad7f507852adf41a2ca33d5cb7100faeaf8499 /Documentation
parente6d69a60b77a6ea8d5f9d41765c7571bb8d45531 (diff)
parented6a82546d2e8f6b5902269541733814d4adacc2 (diff)
downloadlinux-82023bb7f75b0052f40d3e74169d191c3e4e6286.tar.gz
Merge tag 'pm+acpi-2-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more ACPI and power management updates from Rafael Wysocki:

 - ACPI-based device hotplug fixes for issues introduced recently and a
   fix for an older error code path bug in the ACPI PCI host bridge
   driver

 - Fix for recently broken OMAP cpufreq build from Viresh Kumar

 - Fix for a recent hibernation regression related to s2disk

 - Fix for a locking-related regression in the ACPI EC driver from
   Puneet Kumar

 - System suspend error code path fix related to runtime PM and runtime
   PM documentation update from Ulf Hansson

 - cpufreq's conservative governor fix from Xiaoguang Chen

 - New processor IDs for intel_idle and turbostat and removal of an
   obsolete Kconfig option from Len Brown

 - New device IDs for the ACPI LPSS (Low-Power Subsystem) driver and
   ACPI-based PCI hotplug (ACPIPHP) cleanup from Mika Westerberg

 - Removal of several ACPI video DMI blacklist entries that are not
   necessary any more from Aaron Lu

 - Rework of the ACPI companion representation in struct device and code
   cleanup related to that change from Rafael J Wysocki, Lan Tianyu and
   Jarkko Nikula

 - Fixes for assigning names to ACPI-enumerated I2C and SPI devices from
   Jarkko Nikula

* tag 'pm+acpi-2-3.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (24 commits)
  PCI / hotplug / ACPI: Drop unused acpiphp_debug declaration
  ACPI / scan: Set flags.match_driver in acpi_bus_scan_fixed()
  ACPI / PCI root: Clear driver_data before failing enumeration
  ACPI / hotplug: Fix PCI host bridge hot removal
  ACPI / hotplug: Fix acpi_bus_get_device() return value check
  cpufreq: governor: Remove fossil comment in the cpufreq_governor_dbs()
  ACPI / video: clean up DMI table for initial black screen problem
  ACPI / EC: Ensure lock is acquired before accessing ec struct members
  PM / Hibernate: Do not crash kernel in free_basic_memory_bitmaps()
  ACPI / AC: Remove struct acpi_device pointer from struct acpi_ac
  spi: Use stable dev_name for ACPI enumerated SPI slaves
  i2c: Use stable dev_name for ACPI enumerated I2C slaves
  ACPI: Provide acpi_dev_name accessor for struct acpi_device device name
  ACPI / bind: Use (put|get)_device() on ACPI device objects too
  ACPI: Eliminate the DEVICE_ACPI_HANDLE() macro
  ACPI / driver core: Store an ACPI device pointer in struct acpi_dev_node
  cpufreq: OMAP: Fix compilation error 'r & ret undeclared'
  PM / Runtime: Fix error path for prepare
  PM / Runtime: Update documentation around probe|remove|suspend
  cpufreq: conservative: set requested_freq to policy max when it is over policy max
  ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/power/runtime_pm.txt14
1 files changed, 6 insertions, 8 deletions
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 0f54333b0ff2..b6ce00b2be9a 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -547,13 +547,11 @@ helper functions described in Section 4.  In that case, pm_runtime_resume()
 should be used.  Of course, for this purpose the device's runtime PM has to be
 enabled earlier by calling pm_runtime_enable().
 
-If the device bus type's or driver's ->probe() callback runs
-pm_runtime_suspend() or pm_runtime_idle() or their asynchronous counterparts,
-they will fail returning -EAGAIN, because the device's usage counter is
-incremented by the driver core before executing ->probe().  Still, it may be
-desirable to suspend the device as soon as ->probe() has finished, so the driver
-core uses pm_runtime_put_sync() to invoke the subsystem-level idle callback for
-the device at that time.
+It may be desirable to suspend the device once ->probe() has finished.
+Therefore the driver core uses the asyncronous pm_request_idle() to submit a
+request to execute the subsystem-level idle callback for the device at that
+time.  A driver that makes use of the runtime autosuspend feature, may want to
+update the last busy mark before returning from ->probe().
 
 Moreover, the driver core prevents runtime PM callbacks from racing with the bus
 notifier callback in __device_release_driver(), which is necessary, because the
@@ -656,7 +654,7 @@ out the following operations:
     __pm_runtime_disable() with 'false' as the second argument for every device
     right before executing the subsystem-level .suspend_late() callback for it.
 
-  * During system resume it calls pm_runtime_enable() and pm_runtime_put_sync()
+  * During system resume it calls pm_runtime_enable() and pm_runtime_put()
     for every device right after executing the subsystem-level .resume_early()
     callback and right after executing the subsystem-level .resume() callback
     for it, respectively.