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A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Kernel Functions for Drivers

pci_save_config_regs(9F)

INTERFACE LEVEL
ARGUMENTS
DESCRIPTION
RETURN VALUES
CONTEXT
EXAMPLES
ATTRIBUTES
SEE ALSO

NAME

pci_save_config_regs, pci_restore_config_regs - save and restore the PCI configuration registers

SYNOPSIS

#include <sys/ddi.h> #include <sys/sunddi.h> int pci_save_config_regs(dev_info_t *dip);

int pci_restore_config_regs(dev_info_t *dip);

ARGUMENTS

dip: Pointer to the device's dev_info structure.

DESCRIPTION

pci_save_config_regs() saves the current configuration registers on persistent system memory. pci_restore_config_regs() restores configuration registers previously saved by pci_save_config_regs().

pci_save_config_regs() should be called by the driver's power() entry point before powering a device off (to PCI state D3). Likewise, pci_restore_config_regs() should be called after powering a device on (from PCI state D3), but before accessing the device. See power(9E).

RETURN VALUES

pci_save_config_regs() and pci_restore_config_regs() return:

DDI_SUCCESS: Operation completed successfully.
DDI_FAILURE: Operation failed to complete successfully.

CONTEXT

Both these functions can be called from user or kernel context.

EXAMPLES

Example 1. Invoking the save and restore functions

static int
xx_power(dev_info_t *dip, int component, int level) {
   struct xx *xx;
   int rval = DDI_SUCCESS;

   xx = ddi_get_soft_state(xx_softstate, ddi_get_instance(dip));
   if (xx == NULL) {
       return (DDI_FAILURE);
   }

   mutex_enter(&xx->x_mutex);

   switch (level) {
   case PM_LEVEL_D0:
       XX_POWER_ON(xx);
       if (pci_restore_config_regs(dip) == DDI_FAILURE) {
           /*
            * appropriate error path handling here
            */
           ...
           rval = DDI_FAILURE;
           }
       break;

   case PM_LEVEL_D3:
       if (pci_save_config_regs(dip) == DDI_FAILURE) {
            /*
             * appropriate error path handling here
             */
            ...
            rval = DDI_FAILURE;
            } 
        else {
            XX_POWER_OFF(xx);
        }
        break;
       
    default:
          rval = DDI_FAILURE;
          break;
    }

    mutex_exit(&xx->x_mutex);
    return (rval);
}

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE	ATTRIBUTE VALUE
Interface Stability	Evolving