Commit 18606557 authored by Dan Williams's avatar Dan Williams
Browse files

isci: unify remote_device start_io_handlers 



Implement all states in scic_sds_remote_device_start_io() and delete the
state handler.

Reported-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
parent 81515182

drivers/scsi/isci/remote_device.c

+125 −209
Original line number Diff line number Diff line
@@ -305,22 +305,132 @@ enum sci_status scic_sds_remote_device_event_handler( 
	return sci_dev->state_handlers->event_handler(sci_dev, event_code);

}



/**

 *

 * @controller: The controller that is starting the io request.

 * @sci_dev: The remote device for which the start io handling is being

 *    requested.

 * @io_request: The io request that is being started.

 *

 * This method invokes the remote device start io handler. enum sci_status

 */

enum sci_status scic_sds_remote_device_start_io(

	struct scic_sds_controller *controller,

static void scic_sds_remote_device_start_request(struct scic_sds_remote_device *sci_dev,

						 struct scic_sds_request *sci_req,

						 enum sci_status status)

{

	struct scic_sds_port *sci_port = sci_dev->owning_port;



	/* cleanup requests that failed after starting on the port */

	if (status != SCI_SUCCESS)

		scic_sds_port_complete_io(sci_port, sci_dev, sci_req);

	else

		scic_sds_remote_device_increment_request_count(sci_dev);

}



enum sci_status scic_sds_remote_device_start_io(struct scic_sds_controller *scic,

						struct scic_sds_remote_device *sci_dev,

	struct scic_sds_request *io_request)

						struct scic_sds_request *sci_req)

{

	return sci_dev->state_handlers->start_io_handler(

		       sci_dev, io_request);

	struct sci_base_state_machine *sm = &sci_dev->state_machine;

	enum scic_sds_remote_device_states state = sm->current_state_id;

	struct scic_sds_port *sci_port = sci_dev->owning_port;

	enum sci_status status;



	switch (state) {

	case SCI_BASE_REMOTE_DEVICE_STATE_INITIAL:

	case SCI_BASE_REMOTE_DEVICE_STATE_STOPPED:

	case SCI_BASE_REMOTE_DEVICE_STATE_STARTING:

	case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR:

	case SCI_BASE_REMOTE_DEVICE_STATE_STOPPING:

	case SCI_BASE_REMOTE_DEVICE_STATE_FAILED:

	case SCI_BASE_REMOTE_DEVICE_STATE_RESETTING:

	case SCI_BASE_REMOTE_DEVICE_STATE_FINAL:

	default:

		dev_warn(scirdev_to_dev(sci_dev), "%s: in wrong state: %d\n",

			 __func__, state);

		return SCI_FAILURE_INVALID_STATE;

	case SCI_BASE_REMOTE_DEVICE_STATE_READY:

		/* attempt to start an io request for this device object. The remote

		 * device object will issue the start request for the io and if

		 * successful it will start the request for the port object then

		 * increment its own request count.

		 */

		status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);

		if (status != SCI_SUCCESS)

			return status;



		status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, sci_req);

		if (status != SCI_SUCCESS)

			break;



		status = scic_sds_request_start(sci_req);

		break;

	case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE: {

		/* handle the start io operation for a sata device that is in

		 * the command idle state. - Evalute the type of IO request to

		 * be started - If its an NCQ request change to NCQ substate -

		 * If its any other command change to the CMD substate

		 *

		 * If this is a softreset we may want to have a different

		 * substate.

		 */

		enum scic_sds_remote_device_states new_state;



		status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);

		if (status != SCI_SUCCESS)

			return status;



		status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, sci_req);

		if (status != SCI_SUCCESS)

			break;



		status = sci_req->state_handlers->start_handler(sci_req);

		if (status != SCI_SUCCESS)

			break;



		if (isci_sata_get_sat_protocol(sci_req->ireq) == SAT_PROTOCOL_FPDMA)

			new_state = SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ;

		else {

			sci_dev->working_request = sci_req;

			new_state = SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD;

		}

		sci_base_state_machine_change_state(sm, new_state);

		break;

	}

	case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ:

		if (isci_sata_get_sat_protocol(sci_req->ireq) == SAT_PROTOCOL_FPDMA) {

			status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);

			if (status != SCI_SUCCESS)

				return status;



			status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, sci_req);

			if (status != SCI_SUCCESS)

				break;



			status = sci_req->state_handlers->start_handler(sci_req);

		} else

			return SCI_FAILURE_INVALID_STATE;

		break;

	case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET:

		return SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED;

	case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE:

		status = scic_sds_port_start_io(sci_port, sci_dev, sci_req);

		if (status != SCI_SUCCESS)

			return status;



		status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, sci_req);

		if (status != SCI_SUCCESS)

			break;



		status = scic_sds_request_start(sci_req);

		if (status != SCI_SUCCESS)

			break;



		sci_dev->working_request = sci_req;

		sci_base_state_machine_change_state(&sci_dev->state_machine,

						    SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD);

		break;

	case SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD:

	case SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD:

		/* device is already handling a command it can not accept new commands

		 * until this one is complete.

		 */

		return SCI_FAILURE_INVALID_STATE;

	}



	scic_sds_remote_device_start_request(sci_dev, sci_req, status);

	return status;

}



/**
@@ -409,32 +519,6 @@ static void remote_device_resume_done(void *_dev) 
	}

}



/**

 *

 * @device: This parameter specifies the device for which the request is being

 *    started.

 * @request: This parameter specifies the request being started.

 * @status: This parameter specifies the current start operation status.

 *

 * This method will perform the STP request start processing common to IO

 * requests and task requests of all types. none

 */

static void scic_sds_remote_device_start_request(

	struct scic_sds_remote_device *sci_dev,

	struct scic_sds_request *sci_req,

	enum sci_status status)

{

	/* We still have a fault in starting the io complete it on the port */

	if (status == SCI_SUCCESS)

		scic_sds_remote_device_increment_request_count(sci_dev);

	else{

		sci_dev->owning_port->state_handlers->complete_io_handler(

			sci_dev->owning_port, sci_dev, sci_req

			);

	}

}





/**

 *

 * @request: This parameter specifies the request being continued.
@@ -699,35 +783,6 @@ static enum sci_status scic_sds_remote_device_ready_state_start_task_handler( 
	return result;

}



/*

 * This method will attempt to start an io request for this device object. The

 * remote device object will issue the start request for the io and if

 * successful it will start the request for the port object then increment its

 * own requet count. enum sci_status SCI_SUCCESS if the io request is started for

 * this device object. SCI_FAILURE_INSUFFICIENT_RESOURCES if the io request

 * object could not get the resources to start.

 */

static enum sci_status scic_sds_remote_device_ready_state_start_io_handler(

	struct scic_sds_remote_device *sci_dev,

	struct scic_sds_request *request)

{

	enum sci_status result;



	/* See if the port is in a state where we can start the IO request */

	result = scic_sds_port_start_io(

		scic_sds_remote_device_get_port(sci_dev), sci_dev, request);



	if (result == SCI_SUCCESS) {

		result = scic_sds_remote_node_context_start_io(&sci_dev->rnc, request);

		if (result == SCI_SUCCESS)

			result = scic_sds_request_start(request);



		scic_sds_remote_device_start_request(sci_dev, request, result);

	}



	return result;

}



/*

 * This method will complete the request for the remote device object.  The

 * method will call the completion handler for the request object and if
@@ -920,48 +975,6 @@ static enum sci_status scic_sds_stp_remote_device_ready_substate_start_request_h 
	return SCI_FAILURE_RESET_DEVICE_PARTIAL_SUCCESS;

}



/* handle the start io operation for a sata device that is in the command idle

 * state. - Evalute the type of IO request to be started - If its an NCQ

 * request change to NCQ substate - If its any other command change to the CMD

 * substate

 *

 * If this is a softreset we may want to have a different substate.

 */

static enum sci_status scic_sds_stp_remote_device_ready_idle_substate_start_io_handler(

	struct scic_sds_remote_device *sci_dev,

	struct scic_sds_request *request)

{

	enum sci_status status;

	struct isci_request *isci_request = request->ireq;

	enum scic_sds_remote_device_states new_state;



	/* Will the port allow the io request to start? */

	status = sci_dev->owning_port->state_handlers->start_io_handler(

			sci_dev->owning_port, sci_dev, request);

	if (status != SCI_SUCCESS)

		return status;



	status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, request);

	if (status != SCI_SUCCESS)

		goto out;



	status = request->state_handlers->start_handler(request);

	if (status != SCI_SUCCESS)

		goto out;



	if (isci_sata_get_sat_protocol(isci_request) == SAT_PROTOCOL_FPDMA)

		new_state = SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ;

	else {

		sci_dev->working_request = request;

		new_state = SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD;

	}

	sci_base_state_machine_change_state(&sci_dev->state_machine, new_state);

out:

	scic_sds_remote_device_start_request(sci_dev, request, status);

	return status;

}





static enum sci_status scic_sds_stp_remote_device_ready_idle_substate_event_handler(

	struct scic_sds_remote_device *sci_dev,

	u32 event_code)
@@ -982,31 +995,6 @@ static enum sci_status scic_sds_stp_remote_device_ready_idle_substate_event_hand 
	return status;

}



static enum sci_status scic_sds_stp_remote_device_ready_ncq_substate_start_io_handler(

	struct scic_sds_remote_device *sci_dev,

	struct scic_sds_request *request)

{

	enum sci_status status;

	struct isci_request *isci_request = request->ireq;

	scic_sds_port_io_request_handler_t start_io;



	if (isci_sata_get_sat_protocol(isci_request) == SAT_PROTOCOL_FPDMA) {

		start_io = sci_dev->owning_port->state_handlers->start_io_handler;

		status = start_io(sci_dev->owning_port, sci_dev, request);

		if (status != SCI_SUCCESS)

			return status;



		status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, request);

		if (status == SCI_SUCCESS)

			status = request->state_handlers->start_handler(request);



		scic_sds_remote_device_start_request(sci_dev, request, status);

	} else

		status = SCI_FAILURE_INVALID_STATE;



	return status;

}



static enum sci_status scic_sds_stp_remote_device_ready_ncq_substate_frame_handler(struct scic_sds_remote_device *sci_dev,

										   u32 frame_index)

{
@@ -1046,16 +1034,6 @@ static enum sci_status scic_sds_stp_remote_device_ready_ncq_substate_frame_handl 
	return status;

}



static enum sci_status scic_sds_stp_remote_device_ready_cmd_substate_start_io_handler(

	struct scic_sds_remote_device *device,

	struct scic_sds_request *request)

{

	/* device is already handling a command it can not accept new commands

	 * until this one is complete.

	 */

	return SCI_FAILURE_INVALID_STATE;

}



static enum sci_status scic_sds_stp_remote_device_ready_cmd_substate_suspend_handler(

	struct scic_sds_remote_device *sci_dev,

	u32 suspend_type)
@@ -1080,13 +1058,6 @@ static enum sci_status scic_sds_stp_remote_device_ready_cmd_substate_frame_handl 
						 frame_index);

}



static enum sci_status scic_sds_stp_remote_device_ready_await_reset_substate_start_io_handler(

	struct scic_sds_remote_device *device,

	struct scic_sds_request *request)

{

	return SCI_FAILURE_REMOTE_DEVICE_RESET_REQUIRED;

}



static enum sci_status scic_sds_stp_remote_device_ready_await_reset_substate_complete_request_handler(

	struct scic_sds_remote_device *device,

	struct scic_sds_request *request)
@@ -1126,46 +1097,6 @@ static void scic_sds_stp_remote_device_ready_idle_substate_resume_complete_handl 
		isci_remote_device_ready(scic->ihost, idev);

}



static enum sci_status scic_sds_smp_remote_device_ready_idle_substate_start_io_handler(

	struct scic_sds_remote_device *sci_dev,

	struct scic_sds_request *sci_req)

{

	enum sci_status status;



	/* Will the port allow the io request to start? */

	status = sci_dev->owning_port->state_handlers->start_io_handler(

			sci_dev->owning_port, sci_dev, sci_req);

	if (status != SCI_SUCCESS)

		return status;



	status = scic_sds_remote_node_context_start_io(&sci_dev->rnc, sci_req);

	if (status != SCI_SUCCESS)

		goto out;



	status = scic_sds_request_start(sci_req);

	if (status != SCI_SUCCESS)

		goto out;



	sci_dev->working_request = sci_req;

	sci_base_state_machine_change_state(&sci_dev->state_machine,

					    SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD);



 out:

	scic_sds_remote_device_start_request(sci_dev, sci_req, status);



	return status;

}



static enum sci_status scic_sds_smp_remote_device_ready_cmd_substate_start_io_handler(

	struct scic_sds_remote_device *device,

	struct scic_sds_request *request)

{

	/* device is already handling a command it can not accept new commands

	 * until this one is complete.

	 */

	return SCI_FAILURE_INVALID_STATE;

}



static enum sci_status

scic_sds_smp_remote_device_ready_cmd_substate_complete_io_handler(struct scic_sds_remote_device *sci_dev,

								  struct scic_sds_request *sci_req)
@@ -1213,7 +1144,6 @@ static enum sci_status scic_sds_smp_remote_device_ready_cmd_substate_frame_handl 


static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_state_handler_table[] = {

	[SCI_BASE_REMOTE_DEVICE_STATE_INITIAL] = {

		.start_io_handler	= scic_sds_remote_device_default_start_request_handler,

		.complete_io_handler	= scic_sds_remote_device_default_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_remote_device_default_start_request_handler,
@@ -1224,7 +1154,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler		= scic_sds_remote_device_default_frame_handler

	},

	[SCI_BASE_REMOTE_DEVICE_STATE_STOPPED] = {

		.start_io_handler	= scic_sds_remote_device_default_start_request_handler,

		.complete_io_handler	= scic_sds_remote_device_default_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_remote_device_default_start_request_handler,
@@ -1235,7 +1164,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler		= scic_sds_remote_device_default_frame_handler

	},

	[SCI_BASE_REMOTE_DEVICE_STATE_STARTING] = {

		.start_io_handler	= scic_sds_remote_device_default_start_request_handler,

		.complete_io_handler	= scic_sds_remote_device_default_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_remote_device_default_start_request_handler,
@@ -1246,7 +1174,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler		= scic_sds_remote_device_default_frame_handler

	},

	[SCI_BASE_REMOTE_DEVICE_STATE_READY] = {

		.start_io_handler	= scic_sds_remote_device_ready_state_start_io_handler,

		.complete_io_handler	= scic_sds_remote_device_ready_state_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_remote_device_ready_state_start_task_handler,
@@ -1257,7 +1184,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler		= scic_sds_remote_device_general_frame_handler,

	},

	[SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_IDLE] = {

		.start_io_handler	= scic_sds_stp_remote_device_ready_idle_substate_start_io_handler,

		.complete_io_handler	= scic_sds_remote_device_default_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_stp_remote_device_ready_substate_start_request_handler,
@@ -1268,7 +1194,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler			= scic_sds_remote_device_default_frame_handler

	},

	[SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_CMD] = {

		.start_io_handler	= scic_sds_stp_remote_device_ready_cmd_substate_start_io_handler,

		.complete_io_handler	= scic_sds_stp_remote_device_complete_request,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_stp_remote_device_ready_substate_start_request_handler,
@@ -1279,7 +1204,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler			= scic_sds_stp_remote_device_ready_cmd_substate_frame_handler

	},

	[SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ] = {

		.start_io_handler	= scic_sds_stp_remote_device_ready_ncq_substate_start_io_handler,

		.complete_io_handler	= scic_sds_stp_remote_device_complete_request,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_stp_remote_device_ready_substate_start_request_handler,
@@ -1290,7 +1214,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler			= scic_sds_stp_remote_device_ready_ncq_substate_frame_handler

	},

	[SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_NCQ_ERROR] = {

		.start_io_handler	= scic_sds_remote_device_default_start_request_handler,

		.complete_io_handler	= scic_sds_stp_remote_device_complete_request,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_stp_remote_device_ready_substate_start_request_handler,
@@ -1301,7 +1224,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler			= scic_sds_remote_device_general_frame_handler

	},

	[SCIC_SDS_STP_REMOTE_DEVICE_READY_SUBSTATE_AWAIT_RESET] = {

		.start_io_handler	= scic_sds_stp_remote_device_ready_await_reset_substate_start_io_handler,

		.complete_io_handler	= scic_sds_stp_remote_device_ready_await_reset_substate_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_stp_remote_device_ready_substate_start_request_handler,
@@ -1312,7 +1234,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler			= scic_sds_remote_device_general_frame_handler

	},

	[SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_IDLE] = {

		.start_io_handler	= scic_sds_smp_remote_device_ready_idle_substate_start_io_handler,

		.complete_io_handler	= scic_sds_remote_device_default_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_remote_device_default_start_request_handler,
@@ -1323,7 +1244,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler		= scic_sds_remote_device_default_frame_handler

	},

	[SCIC_SDS_SMP_REMOTE_DEVICE_READY_SUBSTATE_CMD] = {

		.start_io_handler	= scic_sds_smp_remote_device_ready_cmd_substate_start_io_handler,

		.complete_io_handler	= scic_sds_smp_remote_device_ready_cmd_substate_complete_io_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_remote_device_default_start_request_handler,
@@ -1334,7 +1254,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler		= scic_sds_smp_remote_device_ready_cmd_substate_frame_handler

	},

	[SCI_BASE_REMOTE_DEVICE_STATE_STOPPING] = {

		.start_io_handler	= scic_sds_remote_device_default_start_request_handler,

		.complete_io_handler	= scic_sds_remote_device_stopping_state_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_remote_device_default_start_request_handler,
@@ -1345,7 +1264,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler		= scic_sds_remote_device_general_frame_handler

	},

	[SCI_BASE_REMOTE_DEVICE_STATE_FAILED] = {

		.start_io_handler	= scic_sds_remote_device_default_start_request_handler,

		.complete_io_handler	= scic_sds_remote_device_default_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_remote_device_default_start_request_handler,
@@ -1356,7 +1274,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler		= scic_sds_remote_device_general_frame_handler

	},

	[SCI_BASE_REMOTE_DEVICE_STATE_RESETTING] = {

		.start_io_handler	= scic_sds_remote_device_default_start_request_handler,

		.complete_io_handler	= scic_sds_remote_device_resetting_state_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_remote_device_default_start_request_handler,
@@ -1367,7 +1284,6 @@ static const struct scic_sds_remote_device_state_handler scic_sds_remote_device_ 
		.frame_handler		= scic_sds_remote_device_general_frame_handler

	},

	[SCI_BASE_REMOTE_DEVICE_STATE_FINAL] = {

		.start_io_handler	= scic_sds_remote_device_default_start_request_handler,

		.complete_io_handler	= scic_sds_remote_device_default_complete_request_handler,

		.continue_io_handler	= scic_sds_remote_device_default_continue_request_handler,

		.start_task_handler	= scic_sds_remote_device_default_start_request_handler,

drivers/scsi/isci/remote_device.h

+0 −6
Original line number Diff line number Diff line
@@ -386,12 +386,6 @@ typedef void (*scic_sds_remote_device_ready_not_ready_handler_t)( 
 *

 */

struct scic_sds_remote_device_state_handler {

	/**

	 * The start_io_handler specifies the method invoked when a user

	 * attempts to start an IO request for a remote device.

	 */

	scic_sds_remote_device_request_handler_t start_io_handler;



	/**

	 * The complete_io_handler specifies the method invoked when a user

	 * attempts to complete an IO request for a remote device.