xref: /linux/Documentation/ABI/testing/sysfs-class-devlink (revision 62137364e3e8afcc745846c5c67cacf943149073)
1What:		/sys/class/devlink/.../
2Date:		May 2020
3Contact:	Saravana Kannan <saravanak@google.com>
4Description:
5		Provide a place in sysfs for the device link objects in the
6		kernel at any given time.  The name of a device link directory,
7		denoted as ... above, is of the form <supplier>--<consumer>
8		where <supplier> is the supplier bus:device name and <consumer>
9		is the consumer bus:device name.
10
11What:		/sys/class/devlink/.../auto_remove_on
12Date:		May 2020
13Contact:	Saravana Kannan <saravanak@google.com>
14Description:
15		This file indicates if the device link will ever be
16		automatically removed by the driver core when the consumer and
17		supplier devices themselves are still present.
18
19		This will be one of the following strings:
20
21		- 'consumer unbind'
22		- 'supplier unbind'
23		- 'never'
24
25		'consumer unbind' means the device link will be removed when
26		the consumer's driver is unbound from the consumer device.
27
28		'supplier unbind' means the device link will be removed when
29		the supplier's driver is unbound from the supplier device.
30
31		'never' means the device link will not be automatically removed
32		when as long as the supplier and consumer devices themselves
33		are still present.
34
35What:		/sys/class/devlink/.../consumer
36Date:		May 2020
37Contact:	Saravana Kannan <saravanak@google.com>
38Description:
39		This file is a symlink to the consumer device's sysfs directory.
40
41What:		/sys/class/devlink/.../runtime_pm
42Date:		May 2020
43Contact:	Saravana Kannan <saravanak@google.com>
44Description:
45		This file indicates if the device link has any impact on the
46		runtime power management behavior of the consumer and supplier
47		devices. For example: Making sure the supplier doesn't enter
48		runtime suspend while the consumer is active.
49
50		This will be one of the following strings:
51
52		===   ========================================
53		'0'   Does not affect runtime power management
54		'1'   Affects runtime power management
55		===   ========================================
56
57What:		/sys/class/devlink/.../status
58Date:		May 2020
59Contact:	Saravana Kannan <saravanak@google.com>
60Description:
61		This file indicates the status of the device link. The status
62		of a device link is affected by whether the supplier and
63		consumer devices have been bound to their corresponding
64		drivers. The status of a device link also affects the binding
65		and unbinding of the supplier and consumer devices with their
66		drivers and also affects whether the software state of the
67		supplier device is synced with the hardware state of the
68		supplier device after boot up.
69		See also: sysfs-devices-state_synced.
70
71		This will be one of the following strings:
72
73		- 'not tracked'
74		- 'dormant'
75		- 'available'
76		- 'consumer probing'
77		- 'active'
78		- 'supplier unbinding'
79		- 'unknown'
80
81		'not tracked' means this device link does not track the status
82		and has no impact on the binding, unbinding and syncing the
83		hardware and software device state.
84
85		'dormant' means the supplier and the consumer devices have not
86		bound to their driver.
87
88		'available' means the supplier has bound to its driver and is
89		available to supply resources to the consumer device.
90
91		'consumer probing' means the consumer device is currently
92		trying to bind to its driver.
93
94		'active' means the supplier and consumer devices have both
95		bound successfully to their drivers.
96
97		'supplier unbinding' means the supplier devices is currently in
98		the process of unbinding from its driver.
99
100		'unknown' means the state of the device link is not any of the
101		above. If this is ever the value, there's a bug in the kernel.
102
103What:		/sys/class/devlink/.../supplier
104Date:		May 2020
105Contact:	Saravana Kannan <saravanak@google.com>
106Description:
107		This file is a symlink to the supplier device's sysfs directory.
108
109What:		/sys/class/devlink/.../sync_state_only
110Date:		May 2020
111Contact:	Saravana Kannan <saravanak@google.com>
112Description:
113		This file indicates if the device link is limited to only
114		affecting the syncing of the hardware and software state of the
115		supplier device.
116
117		This will be one of the following strings:
118
119		===  ================================
120		'0'
121		'1'  Affects runtime power management
122		===  ================================
123
124		'0' means the device link can affect other device behaviors
125		like binding/unbinding, suspend/resume, runtime power
126		management, etc.
127
128		'1' means the device link will only affect the syncing of
129		hardware and software state of the supplier device after boot
130		up and doesn't not affect other behaviors of the devices.
131