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ACPI / hotplug: Use device offline/online for graceful hot-removal

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Modify the generic ACPI hotplug code to be able to check if devices
scheduled for hot-removal may be gracefully removed from the system
using the device offline/online mechanism introduced previously.

Namely, make acpi_scan_hot_remove() handling device hot-removal call
device_offline() for all physical companions of the ACPI device nodes
involved in the operation and check the results.  If any of the
device_offline() calls fails, the function will not progress to the
removal phase (which cannot be aborted), unless its (new) force
argument is set (in case of a failing offline it will put the devices
offlined by it back online).

In support of 'forced' device hot-removal, add a new sysfs attribute
'force_remove' that will reside under /sys/firmware/acpi/hotplug/.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
This commit is contained in:
Rafael J. Wysocki
2013-05-03 00:26:16 +02:00
parent 0902a9044f
commit 683058e315
5 changed files with 128 additions and 0 deletions
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10
Documentation/ABI/testing/sysfs-firmware-acpi
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@@ -44,6 +44,16 @@ Description:
or 0 (unset). Attempts to write any other values to it will
cause -EINVAL to be returned.
What: /sys/firmware/acpi/hotplug/force_remove
Date: May 2013
Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Description:
The number in this file (0 or 1) determines whether (1) or not
(0) the ACPI subsystem will allow devices to be hot-removed even
if they cannot be put offline gracefully (from the kernel's
viewpoint). That number can be changed by writing a boolean
value to this file.
What: /sys/firmware/acpi/interrupts/
Date: February 2008
Contact: Len Brown <lenb@kernel.org>