Other Aliasdevice_busy, device_unbusy, device_is_alive, device_is_attached
SYNOPSISIn sys/param.h In sys/bus.h Ft device_state_t Fn device_get_state device_t dev Ft void Fn device_busy device_t dev Ft void Fn device_unbusy device_t dev Ft int Fn device_is_alive device_t dev Ft int Fn device_is_attached device_t dev
DESCRIPTIONThe current state of a device is accessed by calling Fn device_get_state which returns DS_NOTPRESENT DS_ALIVE DS_ATTACHED or DS_BUSY (described in device(9)). To test see if a device was successfully probed, call Fn device_is_alive which simply returns if the state is greater or equal to DS_ALIVE To test see if a device was successfully attached, call Fn device_is_attached which simply returns if the state is greater or equal to DS_ATTACHED
Each device has a busy count which is incremented when Fn device_busy is called and decremented when Fn device_unbusy is called. Both routines return an error if the device state is less than DS_ATTACHED
When Fn device_busy is called on a device in the DS_ATTACHED state, the device changes to the DS_BUSY state. When Fn device_unbusy is called and after decrementing, the busy count for the device is zero, the device changes to the DS_ATTACHED state.
AUTHORSThis manual page was written by An Doug Rabson .