From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- .../ABI/testing/sysfs-devices-state_synced | 29 ++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-devices-state_synced (limited to 'Documentation/ABI/testing/sysfs-devices-state_synced') diff --git a/Documentation/ABI/testing/sysfs-devices-state_synced b/Documentation/ABI/testing/sysfs-devices-state_synced new file mode 100644 index 0000000000..c64636ddac --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-state_synced @@ -0,0 +1,29 @@ +What: /sys/devices/.../state_synced +Date: May 2020 +Contact: Saravana Kannan +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. + + -- cgit v1.2.3