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Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved.
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
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Copyright (c) 2002, Sun Microsystems, Inc. All Rights Reserved.
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
DDI_REMOVING_POWER 9F "Mar 14, 2001"
NAME
ddi_removing_power - check whether DDI_SUSPEND might result in power
being removed from a device
SYNOPSIS
#include <sys/ddi.h> #include <sys/sunddi.h> int ddi_removing_power(dev_info_t *dip);
INTERFACE LEVEL
illumos DDI specific (illumos 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.
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:
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 attributes:
| ATTRIBUTE TYPE ATTRIBUTE VALUE |
| Interface Stability Committed |
SEE ALSO
attributes(5), cpr(7), attach(9E), detach(9E)
Writing Device Drivers