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#include <sys/ddi.h> #include <sys/sunddi.h> int ddi_removing_power(dev_info_t *dip);
Solaris DDI specific (Solaris DDI)
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.
The ddi_removing_power() function supports the following parameter:
dip
pointer to the device's dev_info structure
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.
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:
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);
...
See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Interface Stability | Committed |
attributes(5), cpr(7), attach(9E), detach(9E)
Writing Device Drivers