1 What:		/sys/devices/.../state_synced
2 Date:		May 2020
3 Contact:	Saravana Kannan <saravanak@google.com>
4 Description:
5 		The /sys/devices/.../state_synced attribute is only present for
6 		devices whose bus types or driver provides the .sync_state()
7 		callback. The number read from it (0 or 1) reflects the value
8 		of the device's 'state_synced' field. A value of 0 means the
9 		.sync_state() callback hasn't been called yet. A value of 1
10 		means the .sync_state() callback has been called.
11 
12 		Generally, if a device has sync_state() support and has some of
13 		the resources it provides enabled at the time the kernel starts
14 		(Eg: enabled by hardware reset or bootloader or anything that
15 		run before the kernel starts), then it'll keep those resources
16 		enabled and in a state that's compatible with the state they
17 		were in at the start of the kernel. The device will stop doing
18 		this only when the sync_state() callback has been called --
19 		which happens only when all its consumer devices are registered
20 		and have probed successfully. Resources that were left disabled
21 		at the time the kernel starts are not affected or limited in
22 		any way by sync_state() callbacks.
23 
24 		Writing "1" to this file will force a call to the device's
25 		sync_state() function if it hasn't been called already. The
26 		sync_state() call happens independent of the state of the
27 		consumer devices.
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