Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  firewire: fix NULL pointer deref. and resource leak
  Documentation: correction to debugging-via-ohci1394
  ieee1394: sbp2: fix rescan-scsi-bus
  firewire: fw-sbp2: fix NULL pointer deref. in scsi_remove_device
  firewire: fw-sbp2: fix NULL pointer deref. in slave_alloc
  firewire: fw-sbp2: (try to) avoid I/O errors during reconnect
  firewire: fw-sbp2: enforce a retry of __scsi_add_device if bus generation changed
  firewire: fw-sbp2: sort includes
  firewire: fw-sbp2: logout and login after failed reconnect
  firewire: fw-sbp2: don't add scsi_device twice
  firewire: fw-sbp2: log bus_id at management request failures
  firewire: fw-sbp2: wait for completion of fetch agent reset
  ieee1394: sbp2: add INQUIRY delay workaround
  firewire: fw-sbp2: add INQUIRY delay workaround
  firewire: log GUID of new devices
  firewire: fw-sbp2: don't retry login or reconnect after unplug
  firewire: fix "kobject_add failed for fw* with -EEXIST"
  firewire: fw-sbp2: fix logout before login retry
  firewire: fw-sbp2: unsigned int vs. unsigned

7 files changed, 350 insertions, 109 deletions

diff --git a/Documentation/debugging-via-ohci1394.txt b/Documentation/debugging-via-ohci1394.txt
index de4804e..c360d4e 100644
--- a/Documentation/debugging-via-ohci1394.txt
+++ b/Documentation/debugging-via-ohci1394.txt
@@ -36,14 +36,15 @@ available (notebooks) or too slow for extensive debug information (like ACPI).
 Drivers
 -------
 
-The OHCI-1394 drivers in drivers/firewire and drivers/ieee1394 initialize
-the OHCI-1394 controllers to a working state and can be used to enable
-physical DMA. By default you only have to load the driver, and physical
-DMA access will be granted to all remote nodes, but it can be turned off
-when using the ohci1394 driver.
-
-Because these drivers depend on the PCI enumeration to be completed, an
-initialization routine which can runs pretty early (long before console_init(),
+The ohci1394 driver in drivers/ieee1394 initializes the OHCI-1394 controllers
+to a working state and enables physical DMA by default for all remote nodes.
+This can be turned off by ohci1394's module parameter phys_dma=0.
+
+The alternative firewire-ohci driver in drivers/firewire uses filtered physical
+DMA, hence is not yet suitable for remote debugging.
+
+Because ohci1394 depends on the PCI enumeration to be completed, an
+initialization routine which runs pretty early (long before console_init()
 which makes the printk buffer appear on the console can be called) was written.
 
 To activate it, enable CONFIG_PROVIDE_OHCI1394_DMA_INIT (Kernel hacking menu:
diff --git a/drivers/firewire/fw-cdev.c b/drivers/firewire/fw-cdev.c
index 7e73cba..46bc197 100644
--- a/drivers/firewire/fw-cdev.c
+++ b/drivers/firewire/fw-cdev.c
@@ -109,15 +109,17 @@ static int fw_device_op_open(struct inode *inode, struct file *file)
 	struct client *client;
 	unsigned long flags;
 
-	device = fw_device_from_devt(inode->i_rdev);
+	device = fw_device_get_by_devt(inode->i_rdev);
 	if (device == NULL)
 		return -ENODEV;
 
 	client = kzalloc(sizeof(*client), GFP_KERNEL);
-	if (client == NULL)
+	if (client == NULL) {
+		fw_device_put(device);
 		return -ENOMEM;
+	}
 
-	client->device = fw_device_get(device);
+	client->device = device;
 	INIT_LIST_HEAD(&client->event_list);
 	INIT_LIST_HEAD(&client->resource_list);
 	spin_lock_init(&client->lock);
@@ -644,6 +646,10 @@ static int ioctl_create_iso_context(struct client *client, void *buffer)
 	struct fw_cdev_create_iso_context *request = buffer;
 	struct fw_iso_context *context;
 
+	/* We only support one context at this time. */
+	if (client->iso_context != NULL)
+		return -EBUSY;
+
 	if (request->channel > 63)
 		return -EINVAL;
 
@@ -790,8 +796,9 @@ static int ioctl_start_iso(struct client *client, void *buffer)
 {
 	struct fw_cdev_start_iso *request = buffer;
 
-	if (request->handle != 0)
+	if (client->iso_context == NULL || request->handle != 0)
 		return -EINVAL;
+
 	if (client->iso_context->type == FW_ISO_CONTEXT_RECEIVE) {
 		if (request->tags == 0 || request->tags > 15)
 			return -EINVAL;
@@ -808,7 +815,7 @@ static int ioctl_stop_iso(struct client *client, void *buffer)
 {
 	struct fw_cdev_stop_iso *request = buffer;
 
-	if (request->handle != 0)
+	if (client->iso_context == NULL || request->handle != 0)
 		return -EINVAL;
 
 	return fw_iso_context_stop(client->iso_context);
diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c
index de9066e..2ab13e0 100644
--- a/drivers/firewire/fw-device.c
+++ b/drivers/firewire/fw-device.c
@@ -358,12 +358,9 @@ static ssize_t
 guid_show(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct fw_device *device = fw_device(dev);
-	u64 guid;
 
-	guid = ((u64)device->config_rom[3] << 32) | device->config_rom[4];
-
-	return snprintf(buf, PAGE_SIZE, "0x%016llx\n",
-			(unsigned long long)guid);
+	return snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
+			device->config_rom[3], device->config_rom[4]);
 }
 
 static struct device_attribute fw_device_attributes[] = {
@@ -610,12 +607,14 @@ static DECLARE_RWSEM(idr_rwsem);
 static DEFINE_IDR(fw_device_idr);
 int fw_cdev_major;
 
-struct fw_device *fw_device_from_devt(dev_t devt)
+struct fw_device *fw_device_get_by_devt(dev_t devt)
 {
 	struct fw_device *device;
 
 	down_read(&idr_rwsem);
 	device = idr_find(&fw_device_idr, MINOR(devt));
+	if (device)
+		fw_device_get(device);
 	up_read(&idr_rwsem);
 
 	return device;
@@ -627,13 +626,14 @@ static void fw_device_shutdown(struct work_struct *work)
 		container_of(work, struct fw_device, work.work);
 	int minor = MINOR(device->device.devt);
 
-	down_write(&idr_rwsem);
-	idr_remove(&fw_device_idr, minor);
-	up_write(&idr_rwsem);
-
 	fw_device_cdev_remove(device);
 	device_for_each_child(&device->device, NULL, shutdown_unit);
 	device_unregister(&device->device);
+
+	down_write(&idr_rwsem);
+	idr_remove(&fw_device_idr, minor);
+	up_write(&idr_rwsem);
+	fw_device_put(device);
 }
 
 static struct device_type fw_device_type = {
@@ -682,10 +682,13 @@ static void fw_device_init(struct work_struct *work)
 	}
 
 	err = -ENOMEM;
+
+	fw_device_get(device);
 	down_write(&idr_rwsem);
 	if (idr_pre_get(&fw_device_idr, GFP_KERNEL))
 		err = idr_get_new(&fw_device_idr, device, &minor);
 	up_write(&idr_rwsem);
+
 	if (err < 0)
 		goto error;
 
@@ -717,13 +720,22 @@ static void fw_device_init(struct work_struct *work)
 	 */
 	if (atomic_cmpxchg(&device->state,
 		    FW_DEVICE_INITIALIZING,
-		    FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN)
+		    FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN) {
 		fw_device_shutdown(&device->work.work);
-	else
-		fw_notify("created new fw device %s "
-			  "(%d config rom retries, S%d00)\n",
-			  device->device.bus_id, device->config_rom_retries,
-			  1 << device->max_speed);
+	} else {
+		if (device->config_rom_retries)
+			fw_notify("created device %s: GUID %08x%08x, S%d00, "
+				  "%d config ROM retries\n",
+				  device->device.bus_id,
+				  device->config_rom[3], device->config_rom[4],
+				  1 << device->max_speed,
+				  device->config_rom_retries);
+		else
+			fw_notify("created device %s: GUID %08x%08x, S%d00\n",
+				  device->device.bus_id,
+				  device->config_rom[3], device->config_rom[4],
+				  1 << device->max_speed);
+	}
 
 	/*
 	 * Reschedule the IRM work if we just finished reading the
@@ -741,7 +753,9 @@ static void fw_device_init(struct work_struct *work)
 	idr_remove(&fw_device_idr, minor);
 	up_write(&idr_rwsem);
  error:
-	put_device(&device->device);
+	fw_device_put(device);		/* fw_device_idr's reference */
+
+	put_device(&device->device);	/* our reference */
 }
 
 static int update_unit(struct device *dev, void *data)
diff --git a/drivers/firewire/fw-device.h b/drivers/firewire/fw-device.h
index 0854fe2..43808c0 100644
--- a/drivers/firewire/fw-device.h
+++ b/drivers/firewire/fw-device.h
@@ -77,13 +77,13 @@ fw_device_is_shutdown(struct fw_device *device)
 }
 
 struct fw_device *fw_device_get(struct fw_device *device);
+struct fw_device *fw_device_get_by_devt(dev_t devt);
 void fw_device_put(struct fw_device *device);
 int fw_device_enable_phys_dma(struct fw_device *device);
 
 void fw_device_cdev_update(struct fw_device *device);
 void fw_device_cdev_remove(struct fw_device *device);
 
-struct fw_device *fw_device_from_devt(dev_t devt);
 extern int fw_cdev_major;
 
 struct fw_unit {
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index 19ece9b..5259491 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -28,14 +28,15 @@
  * and many others.
  */
 
+#include <linux/blkdev.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
 #include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
-#include <linux/mod_devicetable.h>
-#include <linux/device.h>
 #include <linux/scatterlist.h>
-#include <linux/dma-mapping.h>
-#include <linux/blkdev.h>
 #include <linux/string.h>
 #include <linux/stringify.h>
 #include <linux/timer.h>
@@ -47,9 +48,9 @@
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_host.h>
 
-#include "fw-transaction.h"
-#include "fw-topology.h"
 #include "fw-device.h"
+#include "fw-topology.h"
+#include "fw-transaction.h"
 
 /*
  * So far only bridges from Oxford Semiconductor are known to support
@@ -82,6 +83,9 @@ MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
  *   Don't use this with devices which don't have this bug.
  *
+ * - delay inquiry
+ *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
+ *
  * - override internal blacklist
  *   Instead of adding to the built-in blacklist, use only the workarounds
  *   specified in the module load parameter.
@@ -91,6 +95,8 @@ MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
 #define SBP2_WORKAROUND_INQUIRY_36	0x2
 #define SBP2_WORKAROUND_MODE_SENSE_8	0x4
 #define SBP2_WORKAROUND_FIX_CAPACITY	0x8
+#define SBP2_WORKAROUND_DELAY_INQUIRY	0x10
+#define SBP2_INQUIRY_DELAY		12
 #define SBP2_WORKAROUND_OVERRIDE	0x100
 
 static int sbp2_param_workarounds;
@@ -100,6 +106,7 @@ MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
 	", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
 	", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
 	", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
+	", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
 	", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
 	", or a combination)");
 
@@ -132,6 +139,7 @@ struct sbp2_logical_unit {
 	int generation;
 	int retries;
 	struct delayed_work work;
+	bool blocked;
 };
 
 /*
@@ -141,16 +149,18 @@ struct sbp2_logical_unit {
 struct sbp2_target {
 	struct kref kref;
 	struct fw_unit *unit;
+	const char *bus_id;
+	struct list_head lu_list;
 
 	u64 management_agent_address;
 	int directory_id;
 	int node_id;
 	int address_high;
-
-	unsigned workarounds;
-	struct list_head lu_list;
-
+	unsigned int workarounds;
 	unsigned int mgt_orb_timeout;
+
+	int dont_block;	/* counter for each logical unit */
+	int blocked;	/* ditto */
 };
 
 /*
@@ -160,7 +170,7 @@ struct sbp2_target {
  */
 #define SBP2_MIN_LOGIN_ORB_TIMEOUT	5000U	/* Timeout in ms */
 #define SBP2_MAX_LOGIN_ORB_TIMEOUT	40000U	/* Timeout in ms */
-#define SBP2_ORB_TIMEOUT		2000	/* Timeout in ms */
+#define SBP2_ORB_TIMEOUT		2000U	/* Timeout in ms */
 #define SBP2_ORB_NULL			0x80000000
 #define SBP2_MAX_SG_ELEMENT_LENGTH	0xf000
 
@@ -297,7 +307,7 @@ struct sbp2_command_orb {
 static const struct {
 	u32 firmware_revision;
 	u32 model;
-	unsigned workarounds;
+	unsigned int workarounds;
 } sbp2_workarounds_table[] = {
 	/* DViCO Momobay CX-1 with TSB42AA9 bridge */ {
 		.firmware_revision	= 0x002800,
@@ -305,6 +315,11 @@ static const struct {
 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
 					  SBP2_WORKAROUND_MODE_SENSE_8,
 	},
+	/* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
+		.firmware_revision	= 0x002800,
+		.model			= 0x000000,
+		.workarounds		= SBP2_WORKAROUND_DELAY_INQUIRY,
+	},
 	/* Initio bridges, actually only needed for some older ones */ {
 		.firmware_revision	= 0x000200,
 		.model			= ~0,
@@ -501,6 +516,9 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 	unsigned int timeout;
 	int retval = -ENOMEM;
 
+	if (function == SBP2_LOGOUT_REQUEST && fw_device_is_shutdown(device))
+		return 0;
+
 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
 	if (orb == NULL)
 		return -ENOMEM;
@@ -553,20 +571,20 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 
 	retval = -EIO;
 	if (sbp2_cancel_orbs(lu) == 0) {
-		fw_error("orb reply timed out, rcode=0x%02x\n",
-			 orb->base.rcode);
+		fw_error("%s: orb reply timed out, rcode=0x%02x\n",
+			 lu->tgt->bus_id, orb->base.rcode);
 		goto out;
 	}
 
 	if (orb->base.rcode != RCODE_COMPLETE) {
-		fw_error("management write failed, rcode 0x%02x\n",
-			 orb->base.rcode);
+		fw_error("%s: management write failed, rcode 0x%02x\n",
+			 lu->tgt->bus_id, orb->base.rcode);
 		goto out;
 	}
 
 	if (STATUS_GET_RESPONSE(orb->status) != 0 ||
 	    STATUS_GET_SBP_STATUS(orb->status) != 0) {
-		fw_error("error status: %d:%d\n",
+		fw_error("%s: error status: %d:%d\n", lu->tgt->bus_id,
 			 STATUS_GET_RESPONSE(orb->status),
 			 STATUS_GET_SBP_STATUS(orb->status));
 		goto out;
@@ -590,29 +608,147 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 
 static void
 complete_agent_reset_write(struct fw_card *card, int rcode,
-			   void *payload, size_t length, void *data)
+			   void *payload, size_t length, void *done)
+{
+	complete(done);
+}
+
+static void sbp2_agent_reset(struct sbp2_logical_unit *lu)
 {
-	struct fw_transaction *t = data;
+	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
+	DECLARE_COMPLETION_ONSTACK(done);
+	struct fw_transaction t;
+	static u32 z;
+
+	fw_send_request(device->card, &t, TCODE_WRITE_QUADLET_REQUEST,
+			lu->tgt->node_id, lu->generation, device->max_speed,
+			lu->command_block_agent_address + SBP2_AGENT_RESET,
+			&z, sizeof(z), complete_agent_reset_write, &done);
+	wait_for_completion(&done);
+}
 
-	kfree(t);
+static void
+complete_agent_reset_write_no_wait(struct fw_card *card, int rcode,
+				   void *payload, size_t length, void *data)
+{
+	kfree(data);
 }
 
-static int sbp2_agent_reset(struct sbp2_logical_unit *lu)
+static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
 {
 	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 	struct fw_transaction *t;
-	static u32 zero;
+	static u32 z;
 
-	t = kzalloc(sizeof(*t), GFP_ATOMIC);
+	t = kmalloc(sizeof(*t), GFP_ATOMIC);
 	if (t == NULL)
-		return -ENOMEM;
+		return;
 
 	fw_send_request(device->card, t, TCODE_WRITE_QUADLET_REQUEST,
 			lu->tgt->node_id, lu->generation, device->max_speed,
 			lu->command_block_agent_address + SBP2_AGENT_RESET,
-			&zero, sizeof(zero), complete_agent_reset_write, t);
+			&z, sizeof(z), complete_agent_reset_write_no_wait, t);
+}
 
-	return 0;
+static void sbp2_set_generation(struct sbp2_logical_unit *lu, int generation)
+{
+	struct fw_card *card = fw_device(lu->tgt->unit->device.parent)->card;
+	unsigned long flags;
+
+	/* serialize with comparisons of lu->generation and card->generation */
+	spin_lock_irqsave(&card->lock, flags);
+	lu->generation = generation;
+	spin_unlock_irqrestore(&card->lock, flags);
+}
+
+static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
+{
+	/*
+	 * We may access dont_block without taking card->lock here:
+	 * All callers of sbp2_allow_block() and all callers of sbp2_unblock()
+	 * are currently serialized against each other.
+	 * And a wrong result in sbp2_conditionally_block()'s access of
+	 * dont_block is rather harmless, it simply misses its first chance.
+	 */
+	--lu->tgt->dont_block;
+}
+
+/*
+ * Blocks lu->tgt if all of the following conditions are met:
+ *   - Login, INQUIRY, and high-level SCSI setup of all of the target's
+ *     logical units have been finished (indicated by dont_block == 0).
+ *   - lu->generation is stale.
+ *
+ * Note, scsi_block_requests() must be called while holding card->lock,
+ * otherwise it might foil sbp2_[conditionally_]unblock()'s attempt to
+ * unblock the target.
+ */
+static void sbp2_conditionally_block(struct sbp2_logical_unit *lu)
+{
+	struct sbp2_target *tgt = lu->tgt;
+	struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
+	struct Scsi_Host *shost =
+		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->lock, flags);
+	if (!tgt->dont_block && !lu->blocked &&
+	    lu->generation != card->generation) {
+		lu->blocked = true;
+		if (++tgt->blocked == 1) {
+			scsi_block_requests(shost);
+			fw_notify("blocked %s\n", lu->tgt->bus_id);
+		}
+	}
+	spin_unlock_irqrestore(&card->lock, flags);
+}
+
+/*
+ * Unblocks lu->tgt as soon as all its logical units can be unblocked.
+ * Note, it is harmless to run scsi_unblock_requests() outside the
+ * card->lock protected section.  On the other hand, running it inside
+ * the section might clash with shost->host_lock.
+ */
+static void sbp2_conditionally_unblock(struct sbp2_logical_unit *lu)
+{
+	struct sbp2_target *tgt = lu->tgt;
+	struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
+	struct Scsi_Host *shost =
+		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+	unsigned long flags;
+	bool unblock = false;
+
+	spin_lock_irqsave(&card->lock, flags);
+	if (lu->blocked && lu->generation == card->generation) {
+		lu->blocked = false;
+		unblock = --tgt->blocked == 0;
+	}
+	spin_unlock_irqrestore(&card->lock, flags);
+
+	if (unblock) {
+		scsi_unblock_requests(shost);
+		fw_notify("unblocked %s\n", lu->tgt->bus_id);
+	}
+}
+
+/*
+ * Prevents future blocking of tgt and unblocks it.
+ * Note, it is harmless to run scsi_unblock_requests() outside the
+ * card->lock protected section.  On the other hand, running it inside
+ * the section might clash with shost->host_lock.
+ */
+static void sbp2_unblock(struct sbp2_target *tgt)
+{
+	struct fw_card *card = fw_device(tgt->unit->device.parent)->card;
+	struct Scsi_Host *shost =
+		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
+	unsigned long flags;
+
+	spin_lock_irqsave(&card->lock, flags);
+	++tgt->dont_block;
+	spin_unlock_irqrestore(&card->lock, flags);
+
+	scsi_unblock_requests(shost);
 }
 
 static void sbp2_release_target(struct kref *kref)
@@ -621,23 +757,24 @@ static void sbp2_release_target(struct kref *kref)
 	struct sbp2_logical_unit *lu, *next;
 	struct Scsi_Host *shost =
 		container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
-	struct fw_device *device = fw_device(tgt->unit->device.parent);
+
+	/* prevent deadlocks */
+	sbp2_unblock(tgt);
 
 	list_for_each_entry_safe(lu, next, &tgt->lu_list, link) {
-		if (lu->sdev)
+		if (lu->sdev) {
 			scsi_remove_device(lu->sdev);
-
-		if (!fw_device_is_shutdown(device))
-			sbp2_send_management_orb(lu, tgt->node_id,
-					lu->generation, SBP2_LOGOUT_REQUEST,
-					lu->login_id, NULL);
+			scsi_device_put(lu->sdev);
+		}
+		sbp2_send_management_orb(lu, tgt->node_id, lu->generation,
+				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
 
 		fw_core_remove_address_handler(&lu->address_handler);
 		list_del(&lu->link);
 		kfree(lu);
 	}
 	scsi_remove_host(shost);
-	fw_notify("released %s\n", tgt->unit->device.bus_id);
+	fw_notify("released %s\n", tgt->bus_id);
 
 	put_device(&tgt->unit->device);
 	scsi_host_put(shost);
@@ -666,33 +803,43 @@ static void sbp2_login(struct work_struct *work)
 {
 	struct sbp2_logical_unit *lu =
 		container_of(work, struct sbp2_logical_unit, work.work);
-	struct Scsi_Host *shost =
-		container_of((void *)lu->tgt, struct Scsi_Host, hostdata[0]);
+	struct sbp2_target *tgt = lu->tgt;
+	struct fw_device *device = fw_device(tgt->unit->device.parent);
+	struct Scsi_Host *shost;
 	struct scsi_device *sdev;
 	struct scsi_lun eight_bytes_lun;
-	struct fw_unit *unit = lu->tgt->unit;
-	struct fw_device *device = fw_device(unit->device.parent);
 	struct sbp2_login_response response;
 	int generation, node_id, local_node_id;
 
+	if (fw_device_is_shutdown(device))
+		goto out;
+
 	generation    = device->generation;
 	smp_rmb();    /* node_id must not be older than generation */
 	node_id       = device->node_id;
 	local_node_id = device->card->node_id;
 
+	/* If this is a re-login attempt, log out, or we might be rejected. */
+	if (lu->sdev)
+		sbp2_send_management_orb(lu, device->node_id, generation,
+				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
+
 	if (sbp2_send_management_orb(lu, node_id, generation,
 				SBP2_LOGIN_REQUEST, lu->lun, &response) < 0) {
-		if (lu->retries++ < 5)
+		if (lu->retries++ < 5) {
 			sbp2_queue_work(lu, DIV_ROUND_UP(HZ, 5));
-		else
-			fw_error("failed to login to %s LUN %04x\n",
-				 unit->device.bus_id, lu->lun);
+		} else {
+			fw_error("%s: failed to login to LUN %04x\n",
+				 tgt->bus_id, lu->lun);
+			/* Let any waiting I/O fail from now on. */
+			sbp2_unblock(lu->tgt);
+		}
 		goto out;
 	}
 
-	lu->generation        = generation;
-	lu->tgt->node_id      = node_id;
-	lu->tgt->address_high = local_node_id << 16;
+	tgt->node_id	  = node_id;
+	tgt->address_high = local_node_id << 16;
+	sbp2_set_generation(lu, generation);
 
 	/* Get command block agent offset and login id. */
 	lu->command_block_agent_address =
@@ -700,8 +847,8 @@ static void sbp2_login(struct work_struct *work)
 		response.command_block_agent.low;
 	lu->login_id = LOGIN_RESPONSE_GET_LOGIN_ID(response);
 
-	fw_notify("logged in to %s LUN %04x (%d retries)\n",
-		  unit->device.bus_id, lu->lun, lu->retries);
+	fw_notify("%s: logged in to LUN %04x (%d retries)\n",
+		  tgt->bus_id, lu->lun, lu->retries);
 
 #if 0
 	/* FIXME: The linux1394 sbp2 does this last step. */
@@ -711,26 +858,62 @@ static void sbp2_login(struct work_struct *work)
 	PREPARE_DELAYED_WORK(&lu->work, sbp2_reconnect);
 	sbp2_agent_reset(lu);
 
+	/* This was a re-login. */
+	if (lu->sdev) {
+		sbp2_cancel_orbs(lu);
+		sbp2_conditionally_unblock(lu);
+		goto out;
+	}
+
+	if (lu->tgt->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
+		ssleep(SBP2_INQUIRY_DELAY);
+
 	memset(&eight_bytes_lun, 0, sizeof(eight_bytes_lun));
 	eight_bytes_lun.scsi_lun[0] = (lu->lun >> 8) & 0xff;
 	eight_bytes_lun.scsi_lun[1] = lu->lun & 0xff;
+	shost = container_of((void *)tgt, struct Scsi_Host, hostdata[0]);
 
 	sdev = __scsi_add_device(shost, 0, 0,
 				 scsilun_to_int(&eight_bytes_lun), lu);
-	if (IS_ERR(sdev)) {
-		sbp2_send_management_orb(lu, node_id, generation,
-				SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
-		/*
-		 * Set this back to sbp2_login so we fall back and
-		 * retry login on bus reset.
-		 */
-		PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
-	} else {
-		lu->sdev = sdev;
+	/*
+	 * FIXME:  We are unable to perform reconnects while in sbp2_login().
+	 * Therefore __scsi_add_device() will get into trouble if a bus reset
+	 * happens in parallel.  It will either fail or leave us with an
+	 * unusable sdev.  As a workaround we check for this and retry the
+	 * whole login and SCSI probing.
+	 */
+
+	/* Reported error during __scsi_add_device() */
+	if (IS_ERR(sdev))
+		goto out_logout_login;
+
+	/* Unreported error during __scsi_add_device() */
+	smp_rmb(); /* get current card generation */
+	if (generation != device->card->generation) {
+		scsi_remove_device(sdev);
 		scsi_device_put(sdev);
+		goto out_logout_login;
 	}
+
+	/* No error during __scsi_add_device() */
+	lu->sdev = sdev;
+	sbp2_allow_block(lu);
+	goto out;
+
+ out_logout_login:
+	smp_rmb(); /* generation may have changed */
+	generation = device->generation;
+	smp_rmb(); /* node_id must not be older than generation */
+
+	sbp2_send_management_orb(lu, device->node_id, generation,
+				 SBP2_LOGOUT_REQUEST, lu->login_id, NULL);
+	/*
+	 * If a bus reset happened, sbp2_update will have requeued
+	 * lu->work already.  Reset the work from reconnect to login.
+	 */
+	PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
  out:
-	sbp2_target_put(lu->tgt);
+	sbp2_target_put(tgt);
 }
 
 static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
@@ -755,6 +938,8 @@ static int sbp2_add_logical_unit(struct sbp2_target *tgt, int lun_entry)
 	lu->sdev = NULL;
 	lu->lun  = lun_entry & 0xffff;
 	lu->retries = 0;
+	lu->blocked = false;
+	++tgt->dont_block;
 	INIT_LIST_HEAD(&lu->orb_list);
 	INIT_DELAYED_WORK(&lu->work, sbp2_login);
 
@@ -813,7 +998,7 @@ static int sbp2_scan_unit_dir(struct sbp2_target *tgt, u32 *directory,
 			if (timeout > tgt->mgt_orb_timeout)
 				fw_notify("%s: config rom contains %ds "
 					  "management ORB timeout, limiting "
-					  "to %ds\n", tgt->unit->device.bus_id,
+					  "to %ds\n", tgt->bus_id,
 					  timeout / 1000,
 					  tgt->mgt_orb_timeout / 1000);
 			break;
@@ -836,12 +1021,12 @@ static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
 				  u32 firmware_revision)
 {
 	int i;
-	unsigned w = sbp2_param_workarounds;
+	unsigned int w = sbp2_param_workarounds;
 
 	if (w)
 		fw_notify("Please notify linux1394-devel@lists.sourceforge.net "
 			  "if you need the workarounds parameter for %s\n",
-			  tgt->unit->device.bus_id);
+			  tgt->bus_id);
 
 	if (w & SBP2_WORKAROUND_OVERRIDE)
 		goto out;
@@ -863,8 +1048,7 @@ static void sbp2_init_workarounds(struct sbp2_target *tgt, u32 model,
 	if (w)
 		fw_notify("Workarounds for %s: 0x%x "
 			  "(firmware_revision 0x%06x, model_id 0x%06x)\n",
-			  tgt->unit->device.bus_id,
-			  w, firmware_revision, model);
+			  tgt->bus_id, w, firmware_revision, model);
 	tgt->workarounds = w;
 }
 
@@ -888,6 +1072,7 @@ static int sbp2_probe(struct device *dev)
 	tgt->unit = unit;
 	kref_init(&tgt->kref);
 	INIT_LIST_HEAD(&tgt->lu_list);
+	tgt->bus_id = unit->device.bus_id;
 
 	if (fw_device_enable_phys_dma(device) < 0)
 		goto fail_shost_put;
@@ -938,10 +1123,13 @@ static void sbp2_reconnect(struct work_struct *work)
 {
 	struct sbp2_logical_unit *lu =
 		container_of(work, struct sbp2_logical_unit, work.work);
-	struct fw_unit *unit = lu->tgt->unit;
-	struct fw_device *device = fw_device(unit->device.parent);
+	struct sbp2_target *tgt = lu->tgt;
+	struct fw_device *device = fw_device(tgt->unit->device.parent);
 	int generation, node_id, local_node_id;
 
+	if (fw_device_is_shutdown(device))
+		goto out;
+
 	generation    = device->generation;
 	smp_rmb();    /* node_id must not be older than generation */
 	node_id       = device->node_id;
@@ -950,10 +1138,17 @@ static void sbp2_reconnect(struct work_struct *work)
 	if (sbp2_send_management_orb(lu, node_id, generation,
 				     SBP2_RECONNECT_REQUEST,
 				     lu->login_id, NULL) < 0) {
-		if (lu->retries++ >= 5) {
-			fw_error("failed to reconnect to %s\n",
-				 unit->device.bus_id);
-			/* Fall back and try to log in again. */
+		/*
+		 * If reconnect was impossible even though we are in the
+		 * current generation, fall back and try to log in again.
+		 *
+		 * We could check for "Function rejected" status, but
+		 * looking at the bus generation as simpler and more general.
+		 */
+		smp_rmb(); /* get current card generation */
+		if (generation == device->card->generation ||
+		    lu->retries++ >= 5) {
+			fw_error("%s: failed to reconnect\n", tgt->bus_id);
 			lu->retries = 0;
 			PREPARE_DELAYED_WORK(&lu->work, sbp2_login);
 		}
@@ -961,17 +1156,18 @@ static void sbp2_reconnect(struct work_struct *work)
 		goto out;
 	}
 
-	lu->generation        = generation;
-	lu->tgt->node_id      = node_id;
-	lu->tgt->address_high = local_node_id << 16;
+	tgt->node_id      = node_id;
+	tgt->address_high = local_node_id << 16;
+	sbp2_set_generation(lu, generation);
 
-	fw_notify("reconnected to %s LUN %04x (%d retries)\n",
-		  unit->device.bus_id, lu->lun, lu->retries);
+	fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
+		  tgt->bus_id, lu->lun, lu->retries);
 
 	sbp2_agent_reset(lu);
 	sbp2_cancel_orbs(lu);
+	sbp2_conditionally_unblock(lu);
  out:
-	sbp2_target_put(lu->tgt);
+	sbp2_target_put(tgt);
 }
 
 static void sbp2_update(struct fw_unit *unit)
@@ -986,6 +1182,7 @@ static void sbp2_update(struct fw_unit *unit)
 	 * Iteration over tgt->lu_list is therefore safe here.
 	 */
 	list_for_each_entry(lu, &tgt->lu_list, link) {
+		sbp2_conditionally_block(lu);
 		lu->retries = 0;
 		sbp2_queue_work(lu, 0);
 	}
@@ -1063,7 +1260,7 @@ complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
 
 	if (status != NULL) {
 		if (STATUS_GET_DEAD(*status))
-			sbp2_agent_reset(orb->lu);
+			sbp2_agent_reset_no_wait(orb->lu);
 
 		switch (STATUS_GET_RESPONSE(*status)) {
 		case SBP2_STATUS_REQUEST_COMPLETE:
@@ -1089,6 +1286,7 @@ complete_command_orb(struct sbp2_orb *base_orb, struct sbp2_status *status)
 		 * or when sending the write (less likely).
 		 */
 		result = DID_BUS_BUSY << 16;
+		sbp2_conditionally_block(orb->lu);
 	}
 
 	dma_unmap_single(device->card->device, orb->base.request_bus,
@@ -1197,7 +1395,7 @@ static int sbp2_scsi_queuecommand(struct scsi_cmnd *cmd, scsi_done_fn_t done)
 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
 	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 	struct sbp2_command_orb *orb;
-	unsigned max_payload;
+	unsigned int max_payload;
 	int retval = SCSI_MLQUEUE_HOST_BUSY;
 
 	/*
@@ -1275,6 +1473,10 @@ static int sbp2_scsi_slave_alloc(struct scsi_device *sdev)
 {
 	struct sbp2_logical_unit *lu = sdev->hostdata;
 
+	/* (Re-)Adding logical units via the SCSI stack is not supported. */
+	if (!lu)
+		return -ENOSYS;
+
 	sdev->allow_restart = 1;
 
 	/*
@@ -1319,7 +1521,7 @@ static int sbp2_scsi_abort(struct scsi_cmnd *cmd)
 {
 	struct sbp2_logical_unit *lu = cmd->device->hostdata;
 
-	fw_notify("sbp2_scsi_abort\n");
+	fw_notify("%s: sbp2_scsi_abort\n", lu->tgt->bus_id);
 	sbp2_agent_reset(lu);
 	sbp2_cancel_orbs(lu);
 
diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index 28e155a..9e2b1964 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -183,6 +183,9 @@ MODULE_PARM_DESC(exclusive_login, "Exclusive login to sbp2 device "
  *   Avoids access beyond actual disk limits on devices with an off-by-one bug.
  *   Don't use this with devices which don't have this bug.
  *
+ * - delay inquiry
+ *   Wait extra SBP2_INQUIRY_DELAY seconds after login before SCSI inquiry.
+ *
  * - override internal blacklist
  *   Instead of adding to the built-in blacklist, use only the workarounds
  *   specified in the module load parameter.
@@ -195,6 +198,7 @@ MODULE_PARM_DESC(workarounds, "Work around device bugs (default = 0"
 	", 36 byte inquiry = "    __stringify(SBP2_WORKAROUND_INQUIRY_36)
 	", skip mode page 8 = "   __stringify(SBP2_WORKAROUND_MODE_SENSE_8)
 	", fix capacity = "       __stringify(SBP2_WORKAROUND_FIX_CAPACITY)
+	", delay inquiry = "      __stringify(SBP2_WORKAROUND_DELAY_INQUIRY)
 	", override internal blacklist = " __stringify(SBP2_WORKAROUND_OVERRIDE)
 	", or a combination)");
 
@@ -357,6 +361,11 @@ static const struct {
 		.workarounds		= SBP2_WORKAROUND_INQUIRY_36 |
 					  SBP2_WORKAROUND_MODE_SENSE_8,
 	},
+	/* DViCO Momobay FX-3A with TSB42AA9A bridge */ {
+		.firmware_revision	= 0x002800,
+		.model_id		= 0x000000,
+		.workarounds		= SBP2_WORKAROUND_DELAY_INQUIRY,
+	},
 	/* Initio bridges, actually only needed for some older ones */ {
 		.firmware_revision	= 0x000200,
 		.model_id		= SBP2_ROM_VALUE_WILDCARD,
@@ -914,6 +923,9 @@ static int sbp2_start_device(struct sbp2_lu *lu)
 	sbp2_agent_reset(lu, 1);
 	sbp2_max_speed_and_size(lu);
 
+	if (lu->workarounds & SBP2_WORKAROUND_DELAY_INQUIRY)
+		ssleep(SBP2_INQUIRY_DELAY);
+
 	error = scsi_add_device(lu->shost, 0, lu->ud->id, 0);
 	if (error) {
 		SBP2_ERR("scsi_add_device failed");
@@ -1962,6 +1974,9 @@ static int sbp2scsi_slave_alloc(struct scsi_device *sdev)
 {
 	struct sbp2_lu *lu = (struct sbp2_lu *)sdev->host->hostdata[0];
 
+	if (sdev->lun != 0 || sdev->id != lu->ud->id || sdev->channel != 0)
+		return -ENODEV;
+
 	lu->sdev = sdev;
 	sdev->allow_restart = 1;
 
diff --git a/drivers/ieee1394/sbp2.h b/drivers/ieee1394/sbp2.h
index d2ecb0d..80d8e09 100644
--- a/drivers/ieee1394/sbp2.h
+++ b/drivers/ieee1394/sbp2.h
@@ -343,6 +343,8 @@ enum sbp2lu_state_types {
 #define SBP2_WORKAROUND_INQUIRY_36	0x2
 #define SBP2_WORKAROUND_MODE_SENSE_8	0x4
 #define SBP2_WORKAROUND_FIX_CAPACITY	0x8
+#define SBP2_WORKAROUND_DELAY_INQUIRY	0x10
+#define SBP2_INQUIRY_DELAY		12
 #define SBP2_WORKAROUND_OVERRIDE	0x100
 
 #endif /* SBP2_H */