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: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index c196333..432c35a 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -62,7 +62,8 @@
/* 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 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 @@
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 @@
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 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 @@
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 @@
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) {
@@ -1088,8 +1123,11 @@
{
struct sbp2_device *sd = unit->device.driver_data;
- scsi_remove_host(sd->scsi_host);
- scsi_host_put(sd->scsi_host);
+ 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>");