path: root/Documentation/power
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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/power
parente6d69a60b77a6ea8d5f9d41765c7571bb8d45531 (diff)
parented6a82546d2e8f6b5902269541733814d4adacc2 (diff)
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/power')
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.

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