Kernel Functions for Drivers               ddiremovingpower(9F)



NAME
     ddiremovingpower - check whether DISUSPEND might  result
     in power being removed from a device

SYNOPSIS
     #include 
     #include 



     int ddiremovingpower(devinfot *dip);


INTERFACE LEVEL
     Solaris DI specific (Solaris DI)

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


     ddiremovingpower() 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 ddiremovingpower()  function  supports  the  following
     parameter:

     dip    pointer to the device's devinfo structure


RETURN VALUES
     The ddiremovingpower() function returns:

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


     0    Power will not be removed by the framework as a  result
          of the pending DISUSPEND 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               ddiremovingpower(9F)



       int
            xxdetach(devinfot *dip, ddidetachcmdt cmd)
            {

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


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



     
           ATRIBUTE TYPE               ATRIBUTE 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