xref: /freebsd/share/man/man9/device_get_state.9 (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
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29.Dd June 16, 1998
30.Dt DEVICE_GET_STATE 9
31.Os
32.Sh NAME
33.Nm device_get_state ,
34.Nm device_busy ,
35.Nm device_unbusy ,
36.Nm device_is_alive ,
37.Nm device_is_attached
38.Nd manipulate device state
39.Sh SYNOPSIS
40.In sys/param.h
41.In sys/bus.h
42.Ft device_state_t
43.Fn device_get_state "device_t dev"
44.Ft void
45.Fn device_busy "device_t dev"
46.Ft void
47.Fn device_unbusy "device_t dev"
48.Ft int
49.Fn device_is_alive "device_t dev"
50.Ft int
51.Fn device_is_attached "device_t dev"
52.Sh DESCRIPTION
53The current state of a device is accessed by calling
54.Fn device_get_state
55which returns
56.Dv DS_NOTPRESENT ,
57.Dv DS_ALIVE ,
58.Dv DS_ATTACHED
59or
60.Dv DS_BUSY
61(described in
62.Xr device 9 ) .
63To test see if a device was successfully probed, call
64.Fn device_is_alive
65which simply returns if the state is greater or equal to
66.Dv DS_ALIVE .
67To test see if a device was successfully attached, call
68.Fn device_is_attached
69which simply returns if the state is greater or equal to
70.Dv DS_ATTACHED .
71.Pp
72Each device has a busy count which is incremented when
73.Fn device_busy
74is called and decremented when
75.Fn device_unbusy
76is called.
77Both routines return an error if the device state is less than
78.Dv DS_ATTACHED .
79.Pp
80When
81.Fn device_busy
82is called on a device in the
83.Dv DS_ATTACHED
84state, the device changes to the
85.Dv DS_BUSY
86state.
87When
88.Fn device_unbusy
89is called and after decrementing, the busy count for the device is
90zero, the device changes to the
91.Dv DS_ATTACHED
92state.
93.Sh SEE ALSO
94.Xr device 9
95.Sh AUTHORS
96This manual page was written by
97.An Doug Rabson .
98