Documentation/ABI/testing/sysfs-devices-online
Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-devices-online
File Facts
- System
- Linux kernel
- Corpus path
Documentation/ABI/testing/sysfs-devices-online- Extension
[no extension]- Size
- 1008 bytes
- Lines
- 21
- Domain
- Support Tooling And Documentation
- Bucket
- Documentation
- Inferred role
- Support Tooling And Documentation: Documentation
- Status
- atlas-only
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
Dependency Surface
- No C-style include directives detected by the generator.
Detected Declarations
- No top-level syscall, struct, function, initcall, or export declaration detected by the generator.
Annotated Snippet
What: /sys/devices/.../online
Date: April 2013
Contact: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Description:
The /sys/devices/.../online attribute is only present for
devices whose bus types provide .online() and .offline()
callbacks. The number read from it (0 or 1) reflects the value
of the device's 'offline' field. If that number is 1 and '0'
(or 'n', or 'N') is written to this file, the device bus type's
.offline() callback is executed for the device and (if
successful) its 'offline' field is updated accordingly. In
turn, if that number is 0 and '1' (or 'y', or 'Y') is written to
this file, the device bus type's .online() callback is executed
for the device and (if successful) its 'offline' field is
updated as appropriate.
After a successful execution of the bus type's .offline()
callback the device cannot be used for any purpose until either
it is removed (i.e. device_del() is called for it), or its bus
type's .online() is executed successfully.
Annotation
- Atlas domain: Support Tooling And Documentation / Documentation.
- Implementation status: atlas-only.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.