Documentation/ABI/testing/sysfs-devices-state_synced
Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-devices-state_synced
File Facts
- System
- Linux kernel
- Corpus path
Documentation/ABI/testing/sysfs-devices-state_synced- Extension
[no extension]- Size
- 1374 bytes
- Lines
- 30
- 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/.../state_synced
Date: May 2020
Contact: Saravana Kannan <saravanak@google.com>
Description:
The /sys/devices/.../state_synced attribute is only present for
devices whose bus types or driver provides the .sync_state()
callback. The number read from it (0 or 1) reflects the value
of the device's 'state_synced' field. A value of 0 means the
.sync_state() callback hasn't been called yet. A value of 1
means the .sync_state() callback has been called.
Generally, if a device has sync_state() support and has some of
the resources it provides enabled at the time the kernel starts
(Eg: enabled by hardware reset or bootloader or anything that
run before the kernel starts), then it'll keep those resources
enabled and in a state that's compatible with the state they
were in at the start of the kernel. The device will stop doing
this only when the sync_state() callback has been called --
which happens only when all its consumer devices are registered
and have probed successfully. Resources that were left disabled
at the time the kernel starts are not affected or limited in
any way by sync_state() callbacks.
Writing "1" to this file will force a call to the device's
sync_state() function if it hasn't been called already. The
sync_state() call happens independent of the state of the
consumer devices.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.