en Copyright 2015 Java http://172.16.0.5:8080/history/linux-6.15/Documentation/ABI/testing/sysfs-devices-online#ebab9426 Documentation/ABI: Fix typosFix typos in Documentation/ABI. The changes are in descriptions orcomments where they shouldn't affect use of the ABIs.Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>Reviewed-by: Randy Dunlap <rdunlap@infradead.org>Link: https://lore.kernel.org/r/20230814212822.193684-2-helgaas@kernel.orgSigned-off-by: Jonathan Corbet <corbet@lwn.net> List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-online Mon, 14 Aug 2023 21:28:20 +0000 Bjorn Helgaas <bhelgaas@google.com> http://172.16.0.5:8080/history/linux-6.15/Documentation/ABI/testing/sysfs-devices-online#4f3549d7 Driver core: Add offline/online device operationsIn some cases, graceful hot-removal of devices is not possible,although in principle the devices in question support hotplug.For example, that may happen for the last CPU in the system orfor memory modules holding kernel memory.In those cases it is nice to be able to check if the given devicecan be gracefully hot-removed before triggering a removal procedurethat cannot be aborted or reversed. Unfortunately, however, thekernel currently doesn't provide any support for that.To address that deficiency, introduce support for offline andonline operations that can be performed on devices, respectively,before a hot-removal and in case when it is necessary (or convenient)to put a device back online after a successful offline (that has notbeen followed by removal). The idea is that the offline will failwhenever the given device cannot be gracefully removed from thesystem and it will not be allowed to use the device after asuccessful offline (until a subsequent online) in analogy with theexisting CPU offline/online mechanism.For now, the offline and online operations are introduced at thebus type level, as that should be sufficient for the most urgent usecases (CPUs and memory modules). In the future, however, theapproach may be extended to cover some more complicated deviceoffline/online scenarios involving device drivers etc.The lock_device_hotplug() and unlock_device_hotplug() functions areintroduced because subsequent patches need to put larger pieces ofcode under device_hotplug_lock to prevent race conditions betweendevice offline and removal from happening.Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>Reviewed-by: Toshi Kani <toshi.kani@hp.com> List of files: /linux-6.15/Documentation/ABI/testing/sysfs-devices-online Thu, 02 May 2013 20:15:29 +0000 Rafael J. Wysocki <rafael.j.wysocki@intel.com>