man pages section 9: DDI and DKI Kernel Functions

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Updated: July 2014



csx_RequestIRQ, csx_ReleaseIRQ - request or release IRQ resource


#include <sys/pccard.h>

int32_t csx_RequestIRQ(client_handle_t ch, irq_req_t *ir);
int32_t csx_ReleaseIRQ(client_handle_t ch, irq_req_t *ir);

Interface Level

Solaris DDI Specific (Solaris DDI)



Client handle returned from csx_RegisterClient(9F).


Pointer to an irq_req_t structure.


The function csx_RequestIRQ() requests an IRQ resource and registers the client's IRQ handler with Card Services.

If a client requires an IRQ, csx_RequestIRQ() must be called to request an IRQ resource as well as to register the client's IRQ handler with Card Services. The client will not receive callbacks at the IRQ callback handler until csx_RequestConfiguration(9F) or csx_ModifyConfiguration(9F) has successfully returned when either of these functions are called with the CONF_ENABLE_IRQ_STEERING bit set.

The function csx_ReleaseIRQ() releases a previously requested IRQ resource.

The Card Services IRQ resource list is adjusted by csx_ReleaseIRQ(). Depending on the adapter hardware, the host bus IRQ connection might also be disabled. Client IRQ handlers always run above lock level and so should take care to perform only Solaris operations that are appropriate for an above-lock-level IRQ handler.

csx_RequestIRQ() fails if it has already been called without a corresponding csx_ReleaseIRQ().

Structure Members

The structure members of irq_req_t are:

uint32_t                Socket;          /* socket number */
uint32_t                Attributes;      /* IRQ attribute flags */
csfunction_t            *irq_handler;    /* IRQ handler */
void                    *irq_handler_arg; /* IRQ handler argument */
ddi_iblock_cookie_t     *iblk_cookie;    /* IRQ interrupt 
                                         /*   block cookie */
ddi_idevice_cookie_t    *idev_cookie;    /* IRQ interrupt device 
                                         /*   cookie */

The fields are defined as follows:


Not used in Solaris, but for portability with other Card Services implementations, it should be set to the logical socket number.


This field is bit-mapped. It specifies details about the type of IRQ desired by the client. The following bits are defined:


IRQ is exclusive to this socket. This bit must be set. It indicates that the system IRQ is dedicated to this PC Card.


The client IRQ callback handler entry point is passed in the irq_handler field.


The client can use the irq_handler_arg field to pass client-specific data to the client IRQ callback handler.


These fields must be used by the client to set up mutexes that are used in the client's IRQ callback handler.

For a specific csx_ReleaseIRQ() call, the values in the irq_req_t structure must be the same as those returned from the previous csx_RequestIRQ() call; otherwise, CS_BAD_ARGS is returned and no changes are made to Card Services resources or the socket and adapter hardware.

Return Values


Successful operation.


IRQ description does not match allocation.


IRQ_TYPE_EXCLUSIVE not set, or an unsupported or reserved bit is set.


Client handle is invalid or csx_RequestConfiguration(9F) not done.


Unable to allocate IRQ resources.


csx_RequestIRQ() already done or a previous csx_RequestIRQ() has not been done for a corresponding csx_ReleaseIRQ().


csx_RequestConfiguration(9F) already done or csx_ReleaseConfiguration(9F) has not been done.


No PC Card in socket.


No PCMCIA hardware installed.


These functions may be called from user or kernel context.

See also

csx_ReleaseConfiguration(9F), csx_RequestConfiguration(9F)

PC Card Card 95 Standard, PCMCIA/JEIDA