Manual Pages for UNIX Operating System command usage for man ddi_removing_power

Kernel Functions for Drivers               ddi_removing_power(9F)



NAME
     ddi_removing_power - check whether DDI_SUSPEND might  result
     in power being removed from a device

SYNOPSIS
     #include 
     #include 



     int ddi_removing_power(dev_info_t *dip);


INTERFACE LEVEL
     Solaris DDI specific (Solaris DDI)

DESCRIPTION
     The  ddi_removing_power()  function  indicates   whether   a
     currently  pending  call  into  a  driver's detach(9E) entry
     point with a command of DDI_SUSPEND is likely to  result  in
     power being removed from the device.


     ddi_removing_power() can return true and power still not  be
     removed  from  the  device  due  to a failure to suspend and
     power off the system.

PARAMETERS
     The ddi_removing_power()  function  supports  the  following
     parameter:

     dip    pointer to the device's dev_info structure


RETURN VALUES
     The ddi_removing_power() function returns:

     1    Power might be removed by the framework as a result  of
          the pending DDI_SUSPEND call.


     0    Power will not be removed by the framework as a  result
          of the pending DDI_SUSPEND call.


EXAMPLES
     Example 1 Protecting a Tape from Abrupt Power Removal


     A tape driver that has hardware that would damage  the  tape
     if   power  is  removed  might  include  this  code  in  its
     detach(9E) code:



SunOS 5.11         Last change: 14 March 2001                   1






Kernel Functions for Drivers               ddi_removing_power(9F)



       int
            xxdetach(dev_info_t *dip, ddi_detach_cmd_t cmd)
            {

            ...
                 case DDI_SUSPEND:
                 /*
                  * We do not allow DDI_SUSPEND if power will be removed and
                  * we have a device that damages tape when power is removed
                  * We do support DDI_SUSPEND for Device Reconfiguration,
                  * however.
                  */
                    if (ddi_removing_power(dip) && xxdamages_tape(dip))
                       return (DDI_FAILURE);
                 ...


ATTRIBUTES
     See attributes(5) for descriptions of the  following  attri-
     butes:



     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|


SEE ALSO
     attributes(5), cpr(7), attach(9E), detach(9E)


     Writing Device Drivers




















SunOS 5.11         Last change: 14 March 2001                   2