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Commit 7f37c426 authored by Kristian Høgsberg's avatar Kristian Høgsberg Committed by Stefan Richter
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firewire: Introduce a retry mechanism for reconnects and logins. 



Sometimes we reconnect too soon, sometimes too late.  Adding a retry
mechanism make the reconnect step much more robust.

Signed-off-by: default avatarKristian Høgsberg <krh@redhat.com>
Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 1d3d52c5

drivers/firewire/fw-sbp2.c

+109 −71
Original line number Diff line number Diff line
@@ -62,7 +62,8 @@ struct sbp2_device { 
	/* Timer for flushing ORBs. */

	struct timer_list orb_timer;



	struct work_struct work;

	int retries;

	struct delayed_work work;

	struct Scsi_Host *scsi_host;

};
@@ -511,6 +512,75 @@ static int sbp2_agent_reset(struct fw_unit *unit) 


static int add_scsi_devices(struct fw_unit *unit);

static void remove_scsi_devices(struct fw_unit *unit);

static void sbp2_reconnect(struct work_struct *work);



static void sbp2_login(struct work_struct *work)

{

	struct sbp2_device *sd =

		container_of(work, struct sbp2_device, work.work);

	struct fw_unit *unit = sd->unit;

	struct fw_device *device = fw_device(unit->device.parent);

	struct sbp2_login_response response;

	int generation, node_id, local_node_id, lun, retval;



	/* FIXME: Make this work for multi-lun devices. */

	lun = 0;



	generation    = device->card->generation;

	node_id       = device->node->node_id;

	local_node_id = device->card->local_node->node_id;



	if (sbp2_send_management_orb(unit, node_id, generation,

				     SBP2_LOGIN_REQUEST, lun, &response) < 0) {

		if (sd->retries++ < 5) {

			fw_error("login attempt %d for %s failed, "

				 "rescheduling\n",

				 sd->retries, unit->device.bus_id);

			schedule_delayed_work(&sd->work, DIV_ROUND_UP(HZ, 5));

		} else {

			fw_error("failed to login to %s\n",

				 unit->device.bus_id);

			remove_scsi_devices(unit);

		}

		return;

	}



	sd->generation   = generation;

	sd->node_id      = node_id;

	sd->address_high = local_node_id << 16;



	/* Get command block agent offset and login id. */

	sd->command_block_agent_address =

		((u64) response.command_block_agent.high << 32) |

		response.command_block_agent.low;

	sd->login_id = login_response_get_login_id(response);



	fw_notify("logged in to sbp2 unit %s\n", unit->device.bus_id);

	fw_notify(" - management_agent_address: 0x%012llx\n",

		  (unsigned long long) sd->management_agent_address);

	fw_notify(" - command_block_agent_address: 0x%012llx\n",

		  (unsigned long long) sd->command_block_agent_address);

	fw_notify(" - status write address: 0x%012llx\n",

		  (unsigned long long) sd->address_handler.offset);



#if 0

	/* FIXME: The linux1394 sbp2 does this last step. */

	sbp2_set_busy_timeout(scsi_id);

#endif



	INIT_DELAYED_WORK(&sd->work, sbp2_reconnect);

	sbp2_agent_reset(unit);



	retval = add_scsi_devices(unit);

	if (retval < 0) {

		sbp2_send_management_orb(unit, sd->node_id, sd->generation,

					 SBP2_LOGOUT_REQUEST, sd->login_id,

					 NULL);

		/* Set this back to sbp2_login so we fall back and

		 * retry login on bus reset. */

		INIT_DELAYED_WORK(&sd->work, sbp2_login);

	}

}



static int sbp2_probe(struct device *dev)

{
@@ -518,9 +588,7 @@ static int sbp2_probe(struct device *dev) 
	struct fw_device *device = fw_device(unit->device.parent);

	struct sbp2_device *sd;

	struct fw_csr_iterator ci;

	int i, key, value, lun, retval;

	int node_id, generation, local_node_id;

	struct sbp2_login_response response;

	int i, key, value;

	u32 model, firmware_revision;



	sd = kzalloc(sizeof *sd, GFP_KERNEL);
@@ -586,58 +654,10 @@ static int sbp2_probe(struct device *dev) 
			  unit->device.bus_id,

			  sd->workarounds, firmware_revision, model);



	/* FIXME: Make this work for multi-lun devices. */

	lun = 0;



	generation    = device->card->generation;

	node_id       = device->node->node_id;

	local_node_id = device->card->local_node->node_id;



	/* FIXME: We should probably do this from a keventd callback

	 * and handle retries by rescheduling the work. */

	if (sbp2_send_management_orb(unit, node_id, generation,

				     SBP2_LOGIN_REQUEST, lun, &response) < 0) {

		fw_core_remove_address_handler(&sd->address_handler);

		del_timer_sync(&sd->orb_timer);

		kfree(sd);

		return -EBUSY;

	}



	sd->generation   = generation;

	sd->node_id      = node_id;

	sd->address_high = local_node_id << 16;



	/* Get command block agent offset and login id. */

	sd->command_block_agent_address =

		((u64) response.command_block_agent.high << 32) |

		response.command_block_agent.low;

	sd->login_id = login_response_get_login_id(response);



	fw_notify("logged in to sbp2 unit %s\n", unit->device.bus_id);

	fw_notify(" - management_agent_address: 0x%012llx\n",

		  (unsigned long long) sd->management_agent_address);

	fw_notify(" - command_block_agent_address: 0x%012llx\n",

		  (unsigned long long) sd->command_block_agent_address);

	fw_notify(" - status write address: 0x%012llx\n",

		  (unsigned long long) sd->address_handler.offset);



#if 0

	/* FIXME: The linux1394 sbp2 does this last step. */

	sbp2_set_busy_timeout(scsi_id);

#endif



	sbp2_agent_reset(unit);



	retval = add_scsi_devices(unit);

	if (retval < 0) {

		sbp2_send_management_orb(unit, sd->node_id, sd->generation,

					 SBP2_LOGOUT_REQUEST, sd->login_id,

					 NULL);

		fw_core_remove_address_handler(&sd->address_handler);

		del_timer_sync(&sd->orb_timer);

		kfree(sd);

		return retval;

	}

	/* We schedule work to do the login so we can easily

	 * reschedule retries. */

	INIT_DELAYED_WORK(&sd->work, sbp2_login);

	schedule_delayed_work(&sd->work, 0);



	return 0;

}
@@ -663,28 +683,41 @@ static int sbp2_remove(struct device *dev) 


static void sbp2_reconnect(struct work_struct *work)

{

	struct sbp2_device *sd = container_of(work, struct sbp2_device, work);

	struct sbp2_device *sd =

		container_of(work, struct sbp2_device, work.work);

	struct fw_unit *unit = sd->unit;

	struct fw_device *device = fw_device(unit->device.parent);

	int generation, node_id, local_node_id;



	fw_notify("in sbp2_reconnect, reconnecting to unit %s\n",

		  unit->device.bus_id);



	generation    = device->card->generation;

	node_id       = device->node->node_id;

	local_node_id = device->card->local_node->node_id;



	sbp2_send_management_orb(unit, node_id, generation,

				 SBP2_RECONNECT_REQUEST, sd->login_id, NULL);



	/* FIXME: handle reconnect failures. */



	sbp2_cancel_orbs(unit);

	if (sbp2_send_management_orb(unit, node_id, generation,

				     SBP2_RECONNECT_REQUEST,

				     sd->login_id, NULL) < 0) {

		if (sd->retries++ < 5) {

			fw_error("reconnect attempt %d for %s failed, "

				 "rescheduling\n",

				 sd->retries, unit->device.bus_id);

		} else {

			fw_error("failed to reconnect to %s\n",

				 unit->device.bus_id);

			/* Fall back and try to log in again. */

			sd->retries = 0;

			INIT_DELAYED_WORK(&sd->work, sbp2_login);

		}

		schedule_delayed_work(&sd->work, DIV_ROUND_UP(HZ, 5));

		return;

	}



	sd->generation   = generation;

	sd->node_id      = node_id;

	sd->address_high = local_node_id << 16;



	fw_notify("reconnected to unit %s\n", unit->device.bus_id);

	sbp2_agent_reset(unit);

	sbp2_cancel_orbs(unit);

}



static void sbp2_update(struct fw_unit *unit)
@@ -692,10 +725,9 @@ static void sbp2_update(struct fw_unit *unit) 
	struct fw_device *device = fw_device(unit->device.parent);

	struct sbp2_device *sd = unit->device.driver_data;



	sd->retries = 0;

	fw_device_enable_phys_dma(device);



	INIT_WORK(&sd->work, sbp2_reconnect);

	schedule_work(&sd->work);

	schedule_delayed_work(&sd->work, 0);

}



#define SBP2_UNIT_SPEC_ID_ENTRY	0x0000609e
@@ -1056,6 +1088,9 @@ static int add_scsi_devices(struct fw_unit *unit) 
	struct sbp2_device *sd = unit->device.driver_data;

	int retval, lun;



	if (sd->scsi_host != NULL)

		return 0;



	sd->scsi_host = scsi_host_alloc(&scsi_driver_template,

					sizeof(unsigned long));

	if (sd->scsi_host == NULL) {
@@ -1088,9 +1123,12 @@ static void remove_scsi_devices(struct fw_unit *unit) 
{

	struct sbp2_device *sd = unit->device.driver_data;



	if (sd->scsi_host != NULL) {

		scsi_remove_host(sd->scsi_host);

		scsi_host_put(sd->scsi_host);

	}

	sd->scsi_host = NULL;

}



MODULE_AUTHOR("Kristian Hoegsberg <krh@bitplanet.net>");

MODULE_DESCRIPTION("SCSI over IEEE1394");