Manual Pages for UNIX Operating System command usage for man pm_trans_check

Kernel Functions for Drivers                   pm_trans_check(9F)



NAME
     pm_trans_check - Device power cycle advisory check

SYNOPSIS
     #include 

     int pm_trans_check(struct pm_trans_data *datap, time_t *intervalp);


INTERFACE LEVEL
     Solaris DDI specific (Solaris DDI)

PARAMETERS
     datap    Pointer to a pm_trans_data structure


     intervalp    Pointer to  time  difference  when  next  power
                  cycle will be advised


DESCRIPTION
     The pm_trans_check() function checks  if  a  power-cycle  is
     currently advised based on data in the pm_trans_data  struc-
     ture. This function is provided to prevent damage to devices
     from  excess power cycles; drivers for devices that are sen-
     sitive  to  the  number  of   power   cycles   should   call
     pm_trans_check()   from   their  power(9E)  function  before
     powering-off a device. If  pm_trans_check()  indicates  that
     the device should not be power cycled, the driver should not
     attempt to power cycle the device and should fail  the  call
     to power(9E) entry point.


     If pm_trans_check() returns that it is not advised to  power
     cycle  the  device,  it attempts to calculate when the  next
     power cycle is advised, based on the supplied parameters. In
     such   case,  intervalp  returns  the  time  difference  (in
     seconds) from the current time to when the next power  cycle
     is  advised.  If the time for the next power cycle cannot be
     determined, intervalp indicates 0.


     To avoid excessive calls to the power(9E) entry point during
     a  period  when  power  cycling  is  not advised, the driver
     should mark the corresponding device component busy for  the
     intervalp  time period (if interval is not 0). Conveniently,
     the  driver   can   utilize   the   fact   that   calls   to
     pm_busy_component(9F)  are  stacked. If power cycling is not
     advised, the  driver  can  call  pm_busy_component(9F)   and
     issue  a  timeout(9F)  for the intervalp time. The timeout()
     handler can issue  the  corresponding  pm_idle_component(9F)
     call.



SunOS 5.11          Last change: 16 Jul 2009                    1






Kernel Functions for Drivers                   pm_trans_check(9F)



     The   format   field   of   pm_trans_data   accepts   either
     DC_SCSI_FORMAT  or  DC_SMART_FORMAT.  If the caller provides
     information from a SCSI Log Page, it should set  the  format
     field   to   DC_SCSI_FORMAT,  and  provide   valid  data  in
     svc_date[], lifemax, ncycles and flag in the  pm_scsi_cycles
     structure.  If  the caller provides information from a SMART
     feature  attribute,  it  should  set  the  format  field  to
     DC_SMART_FORMAT  and  provide  valid data in allowed, usedup
     and flag in  the  pm_smart_count  structure,  where  allowed
     indicates  the  normalized  cycle  count before reaching the
     borderline threshold cycle count, and usedup  indicates  the
     normalized consumed cycle count.


     The flag field in  both  pm_scsi_cycles  and  pm_smart_count
     structures is reserved for future use and must be set to 0.

       struct pm_trans_data {
              int format;            /* data format */
              union {
                    struct pm_scsi_cycles scsi_cycles;
                    struct pm_smart_count smart_count;
              } un;
       };


RETURN VALUES
     1     Power cycle is advised.


     0     Power cycle is not advised.


     -1    Error due to invalid argument.


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



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


SEE ALSO
     power.conf(4), attributes(5), power(9E)




SunOS 5.11          Last change: 16 Jul 2009                    2






Kernel Functions for Drivers                   pm_trans_check(9F)



     Writing Device Drivers


     Using Power Management



















































SunOS 5.11          Last change: 16 Jul 2009                    3