X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fblock%2Fub.c;h=c688c25992e44b0a914624735c448e7e7abb1429;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=19c5e59bcfa826966d433c2edd6f921592a7f40f;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/drivers/block/ub.c b/drivers/block/ub.c
index 19c5e59bc..c688c2599 100644
--- a/drivers/block/ub.c
+++ b/drivers/block/ub.c
@@ -8,25 +8,25 @@
  * and is not licensed separately. See file COPYING for details.
  *
  * TODO (sorted by decreasing priority)
- *  -- Kill first_open (Al Viro fixed the block layer now)
- *  -- Do resets with usb_device_reset (needs a thread context, use khubd)
  *  -- set readonly flag for CDs, set removable flag for CF readers
  *  -- do inquiry and verify we got a disk and not a tape (for LUN mismatch)
  *  -- special case some senses, e.g. 3a/0 -> no media present, reduce retries
  *  -- verify the 13 conditions and do bulk resets
  *  -- kill last_pipe and simply do two-state clearing on both pipes
- *  -- verify protocol (bulk) from USB descriptors (maybe...)
- *  -- highmem and sg
+ *  -- highmem
  *  -- move top_sense and work_bcs into separate allocations (if they survive)
  *     for cache purists and esoteric architectures.
+ *  -- Allocate structure for LUN 0 before the first ub_sync_tur, avoid NULL. ?
  *  -- prune comments, they are too volumnous
  *  -- Exterminate P3 printks
  *  -- Resove XXX's
  *  -- Redo "benh's retries", perhaps have spin-up code to handle them. V:D=?
+ *  -- CLEAR, CLR2STS, CLRRS seem to be ripe for refactoring.
  */
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/usb.h>
+#include <linux/usb_usual.h>
 #include <linux/blkdev.h>
 #include <linux/devfs_fs_kernel.h>
 #include <linux/timer.h>
@@ -38,15 +38,72 @@
 #define UB_MAJOR 180
 
 /*
- * Definitions which have to be scattered once we understand the layout better.
+ * The command state machine is the key model for understanding of this driver.
+ *
+ * The general rule is that all transitions are done towards the bottom
+ * of the diagram, thus preventing any loops.
+ *
+ * An exception to that is how the STAT state is handled. A counter allows it
+ * to be re-entered along the path marked with [C].
+ *
+ *       +--------+
+ *       ! INIT   !
+ *       +--------+
+ *           !
+ *        ub_scsi_cmd_start fails ->--------------------------------------\
+ *           !                                                            !
+ *           V                                                            !
+ *       +--------+                                                       !
+ *       ! CMD    !                                                       !
+ *       +--------+                                                       !
+ *           !                                            +--------+      !
+ *         was -EPIPE -->-------------------------------->! CLEAR  !      !
+ *           !                                            +--------+      !
+ *           !                                                !           !
+ *         was error -->------------------------------------- ! --------->\
+ *           !                                                !           !
+ *  /--<-- cmd->dir == NONE ?                                 !           !
+ *  !        !                                                !           !
+ *  !        V                                                !           !
+ *  !    +--------+                                           !           !
+ *  !    ! DATA   !                                           !           !
+ *  !    +--------+                                           !           !
+ *  !        !                           +---------+          !           !
+ *  !      was -EPIPE -->--------------->! CLR2STS !          !           !
+ *  !        !                           +---------+          !           !
+ *  !        !                                !               !           !
+ *  !        !                              was error -->---- ! --------->\
+ *  !      was error -->--------------------- ! ------------- ! --------->\
+ *  !        !                                !               !           !
+ *  !        V                                !               !           !
+ *  \--->+--------+                           !               !           !
+ *       ! STAT   !<--------------------------/               !           !
+ *  /--->+--------+                                           !           !
+ *  !        !                                                !           !
+ * [C]     was -EPIPE -->-----------\                         !           !
+ *  !        !                      !                         !           !
+ *  +<---- len == 0                 !                         !           !
+ *  !        !                      !                         !           !
+ *  !      was error -->--------------------------------------!---------->\
+ *  !        !                      !                         !           !
+ *  +<---- bad CSW                  !                         !           !
+ *  +<---- bad tag                  !                         !           !
+ *  !        !                      V                         !           !
+ *  !        !                 +--------+                     !           !
+ *  !        !                 ! CLRRS  !                     !           !
+ *  !        !                 +--------+                     !           !
+ *  !        !                      !                         !           !
+ *  \------- ! --------------------[C]--------\               !           !
+ *           !                                !               !           !
+ *         cmd->error---\                +--------+           !           !
+ *           !          +--------------->! SENSE  !<----------/           !
+ *         STAT_FAIL----/                +--------+                       !
+ *           !                                !                           V
+ *           !                                V                      +--------+
+ *           \--------------------------------\--------------------->! DONE   !
+ *                                                                   +--------+
  */
 
-/* Transport (despite PR in the name) */
-#define US_PR_BULK	0x50		/* bulk only */
-
-/* Protocol */
-#define US_SC_SCSI	0x06		/* Transparent */
-
 /*
  * This many LUNs per USB device.
  * Every one of them takes a host, see UB_MAX_HOSTS.
@@ -56,7 +113,7 @@
 /*
  */
 
-#define UB_MINORS_PER_MAJOR	8
+#define UB_PARTS_PER_LUN      8
 
 #define UB_MAX_CDB_SIZE      16		/* Corresponds to Bulk */
 
@@ -91,8 +148,6 @@ struct bulk_cs_wrap {
 
 #define US_BULK_CS_WRAP_LEN	13
 #define US_BULK_CS_SIGN		0x53425355	/* spells out 'USBS' */
-/* This is for Olympus Camedia digital cameras */
-#define US_BULK_CS_OLYMPUS_SIGN	0x55425355	/* spells out 'USBU' */
 #define US_BULK_STAT_OK		0
 #define US_BULK_STAT_FAIL	1
 #define US_BULK_STAT_PHASE	2
@@ -105,7 +160,7 @@ struct bulk_cs_wrap {
  */
 struct ub_dev;
 
-#define UB_MAX_REQ_SG	1
+#define UB_MAX_REQ_SG	9	/* cdrecord requires 32KB and maybe a header */
 #define UB_MAX_SECTORS 64
 
 /*
@@ -125,6 +180,7 @@ struct ub_dev;
 #define UB_DIR_ILLEGAL2	2
 #define UB_DIR_WRITE	3
 
+/* P3 */
 #define UB_DIR_CHAR(c)  (((c)==UB_DIR_WRITE)? 'w': \
 			 (((c)==UB_DIR_READ)? 'r': 'n'))
 
@@ -135,27 +191,16 @@ enum ub_scsi_cmd_state {
 	UB_CMDST_CLR2STS,		/* Clearing before requesting status */
 	UB_CMDST_STAT,			/* Status phase */
 	UB_CMDST_CLEAR,			/* Clearing a stall (halt, actually) */
+	UB_CMDST_CLRRS,			/* Clearing before retrying status */
 	UB_CMDST_SENSE,			/* Sending Request Sense */
 	UB_CMDST_DONE			/* Final state */
 };
 
-static char *ub_scsi_cmd_stname[] = {
-	".  ",
-	"Cmd",
-	"dat",
-	"c2s",
-	"sts",
-	"clr",
-	"Sen",
-	"fin"
-};
-
 struct ub_scsi_cmd {
 	unsigned char cdb[UB_MAX_CDB_SIZE];
 	unsigned char cdb_len;
 
 	unsigned char dir;		/* 0 - none, 1 - read, 3 - write. */
-	unsigned char trace_index;
 	enum ub_scsi_cmd_state state;
 	unsigned int tag;
 	struct ub_scsi_cmd *next;
@@ -166,19 +211,23 @@ struct ub_scsi_cmd {
 
 	int stat_count;			/* Retries getting status. */
 
-	/*
-	 * We do not support transfers from highmem pages
-	 * because the underlying USB framework does not do what we need.
-	 */
-	char *data;			/* Requested buffer */
 	unsigned int len;		/* Requested length */
-	// struct scatterlist sgv[UB_MAX_REQ_SG];
+	unsigned int current_sg;
+	unsigned int nsg;		/* sgv[nsg] */
+	struct scatterlist sgv[UB_MAX_REQ_SG];
 
 	struct ub_lun *lun;
 	void (*done)(struct ub_dev *, struct ub_scsi_cmd *);
 	void *back;
 };
 
+struct ub_request {
+	struct request *rq;
+	unsigned int current_try;
+	unsigned int nsg;		/* sgv[nsg] */
+	struct scatterlist sgv[UB_MAX_REQ_SG];
+};
+
 /*
  */
 struct ub_capacity {
@@ -187,28 +236,6 @@ struct ub_capacity {
 	unsigned int bshift;		/* Shift between 512 and hard sects */
 };
 
-/*
- * The SCSI command tracing structure.
- */
-
-#define SCMD_ST_HIST_SZ   8
-#define SCMD_TRACE_SZ    63		/* Less than 4KB of 61-byte lines */
-
-struct ub_scsi_cmd_trace {
-	int hcur;
-	unsigned int tag;
-	unsigned int req_size, act_size;
-	unsigned char op;
-	unsigned char dir;
-	unsigned char key, asc, ascq;
-	char st_hst[SCMD_ST_HIST_SZ];	
-};
-
-struct ub_scsi_trace {
-	int cur;
-	struct ub_scsi_cmd_trace vec[SCMD_TRACE_SZ];
-};
-
 /*
  * This is a direct take-off from linux/include/completion.h
  * The difference is that I do not wait on this thing, just poll.
@@ -272,7 +299,8 @@ struct ub_lun {
 	int changed;			/* Media was changed */
 	int removable;
 	int readonly;
-	int first_open;			/* Kludge. See ub_bd_open. */
+
+	struct ub_request urq;
 
 	/* Use Ingo's mempool if or when we have more than one command. */
 	/*
@@ -290,10 +318,11 @@ struct ub_lun {
  * The USB device instance.
  */
 struct ub_dev {
-	spinlock_t lock;
+	spinlock_t *lock;
 	atomic_t poison;		/* The USB device is disconnected */
 	int openc;			/* protected by ub_lock! */
 					/* kref is too implicit for our taste */
+	int reset;			/* Reset is running */
 	unsigned int tagcnt;
 	char name[12];
 	struct usb_device *dev;
@@ -316,49 +345,66 @@ struct ub_dev {
 	struct urb work_urb;
 	struct timer_list work_timer;
 	int last_pipe;			/* What might need clearing */
+	__le32 signature;		/* Learned signature */
 	struct bulk_cb_wrap work_bcb;
 	struct bulk_cs_wrap work_bcs;
 	struct usb_ctrlrequest work_cr;
 
-	struct ub_scsi_trace tr;
+	struct work_struct reset_work;
+	wait_queue_head_t reset_wait;
+
+	int sg_stat[6];
 };
 
 /*
  */
 static void ub_cleanup(struct ub_dev *sc);
-static int ub_bd_rq_fn_1(struct ub_lun *lun, struct request *rq);
-static int ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
-    struct ub_scsi_cmd *cmd, struct request *rq);
-static int ub_cmd_build_packet(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
-    struct request *rq);
+static int ub_request_fn_1(struct ub_lun *lun, struct request *rq);
+static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_scsi_cmd *cmd, struct ub_request *urq);
+static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_scsi_cmd *cmd, struct ub_request *urq);
 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 static void ub_end_rq(struct request *rq, int uptodate);
+static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_request *urq, struct ub_scsi_cmd *cmd);
 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 static void ub_urb_complete(struct urb *urb, struct pt_regs *pt);
 static void ub_scsi_action(unsigned long _dev);
 static void ub_scsi_dispatch(struct ub_dev *sc);
 static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc);
-static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
+static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd);
 static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
     int stalled_pipe);
 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd);
+static void ub_reset_enter(struct ub_dev *sc, int try);
+static void ub_reset_task(void *arg);
 static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun);
 static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
     struct ub_capacity *ret);
+static int ub_sync_reset(struct ub_dev *sc);
+static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe);
 static int ub_probe_lun(struct ub_dev *sc, int lnum);
 
 /*
  */
+#ifdef CONFIG_USB_LIBUSUAL
+
+#define ub_usb_ids  storage_usb_ids
+#else
+
 static struct usb_device_id ub_usb_ids[] = {
-	// { USB_DEVICE_VER(0x0781, 0x0002, 0x0009, 0x0009) },	/* SDDR-31 */
 	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, US_SC_SCSI, US_PR_BULK) },
 	{ }
 };
 
 MODULE_DEVICE_TABLE(usb, ub_usb_ids);
+#endif /* CONFIG_USB_LIBUSUAL */
 
 /*
  * Find me a way to identify "next free minor" for add_disk(),
@@ -370,126 +416,11 @@ MODULE_DEVICE_TABLE(usb, ub_usb_ids);
 #define UB_MAX_HOSTS  26
 static char ub_hostv[UB_MAX_HOSTS];
 
-static DEFINE_SPINLOCK(ub_lock);	/* Locks globals and ->openc */
+#define UB_QLOCK_NUM 5
+static spinlock_t ub_qlockv[UB_QLOCK_NUM];
+static int ub_qlock_next = 0;
 
-/*
- * The SCSI command tracing procedures.
- */
-
-static void ub_cmdtr_new(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
-{
-	int n;
-	struct ub_scsi_cmd_trace *t;
-
-	if ((n = sc->tr.cur + 1) == SCMD_TRACE_SZ) n = 0;
-	t = &sc->tr.vec[n];
-
-	memset(t, 0, sizeof(struct ub_scsi_cmd_trace));
-	t->tag = cmd->tag;
-	t->op = cmd->cdb[0];
-	t->dir = cmd->dir;
-	t->req_size = cmd->len;
-	t->st_hst[0] = cmd->state;
-
-	sc->tr.cur = n;
-	cmd->trace_index = n;
-}
-
-static void ub_cmdtr_state(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
-{
-	int n;
-	struct ub_scsi_cmd_trace *t;
-
-	t = &sc->tr.vec[cmd->trace_index];
-	if (t->tag == cmd->tag) {
-		if ((n = t->hcur + 1) == SCMD_ST_HIST_SZ) n = 0;
-		t->st_hst[n] = cmd->state;
-		t->hcur = n;
-	}
-}
-
-static void ub_cmdtr_act_len(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
-{
-	struct ub_scsi_cmd_trace *t;
-
-	t = &sc->tr.vec[cmd->trace_index];
-	if (t->tag == cmd->tag)
-		t->act_size = cmd->act_len;
-}
-
-static void ub_cmdtr_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
-    unsigned char *sense)
-{
-	struct ub_scsi_cmd_trace *t;
-
-	t = &sc->tr.vec[cmd->trace_index];
-	if (t->tag == cmd->tag) {
-		t->key = sense[2] & 0x0F;
-		t->asc = sense[12];
-		t->ascq = sense[13];
-	}
-}
-
-static ssize_t ub_diag_show(struct device *dev, char *page)
-{
-	struct usb_interface *intf;
-	struct ub_dev *sc;
-	struct list_head *p;
-	struct ub_lun *lun;
-	int cnt;
-	unsigned long flags;
-	int nc, nh;
-	int i, j;
-	struct ub_scsi_cmd_trace *t;
-
-	intf = to_usb_interface(dev);
-	sc = usb_get_intfdata(intf);
-	if (sc == NULL)
-		return 0;
-
-	cnt = 0;
-	spin_lock_irqsave(&sc->lock, flags);
-
-	cnt += sprintf(page + cnt,
-	    "qlen %d qmax %d\n",
-	    sc->cmd_queue.qlen, sc->cmd_queue.qmax);
-
-	list_for_each (p, &sc->luns) {
-		lun = list_entry(p, struct ub_lun, link);
-		cnt += sprintf(page + cnt,
-		    "lun %u changed %d removable %d readonly %d\n",
-		    lun->num, lun->changed, lun->removable, lun->readonly);
-	}
-
-	if ((nc = sc->tr.cur + 1) == SCMD_TRACE_SZ) nc = 0;
-	for (j = 0; j < SCMD_TRACE_SZ; j++) {
-		t = &sc->tr.vec[nc];
-
-		cnt += sprintf(page + cnt, "%08x %02x", t->tag, t->op);
-		if (t->op == REQUEST_SENSE) {
-			cnt += sprintf(page + cnt, " [sense %x %02x %02x]",
-					t->key, t->asc, t->ascq);
-		} else {
-			cnt += sprintf(page + cnt, " %c", UB_DIR_CHAR(t->dir));
-			cnt += sprintf(page + cnt, " [%5d %5d]",
-					t->req_size, t->act_size);
-		}
-		if ((nh = t->hcur + 1) == SCMD_ST_HIST_SZ) nh = 0;
-		for (i = 0; i < SCMD_ST_HIST_SZ; i++) {
-			cnt += sprintf(page + cnt, " %s",
-					ub_scsi_cmd_stname[(int)t->st_hst[nh]]);
-			if (++nh == SCMD_ST_HIST_SZ) nh = 0;
-		}
-		cnt += sprintf(page + cnt, "\n");
-
-		if (++nc == SCMD_TRACE_SZ) nc = 0;
-	}
-
-	spin_unlock_irqrestore(&sc->lock, flags);
-	return cnt;
-}
-
-static DEVICE_ATTR(diag, S_IRUGO, ub_diag_show, NULL); /* N.B. World readable */
+static DEFINE_SPINLOCK(ub_lock);	/* Locks globals and ->openc */
 
 /*
  * The id allocator.
@@ -532,6 +463,24 @@ static void ub_id_put(int id)
 	spin_unlock_irqrestore(&ub_lock, flags);
 }
 
+/*
+ * This is necessitated by the fact that blk_cleanup_queue does not
+ * necesserily destroy the queue. Instead, it may merely decrease q->refcnt.
+ * Since our blk_init_queue() passes a spinlock common with ub_dev,
+ * we have life time issues when ub_cleanup frees ub_dev.
+ */
+static spinlock_t *ub_next_lock(void)
+{
+	unsigned long flags;
+	spinlock_t *ret;
+
+	spin_lock_irqsave(&ub_lock, flags);
+	ret = &ub_qlockv[ub_qlock_next];
+	ub_qlock_next = (ub_qlock_next + 1) % UB_QLOCK_NUM;
+	spin_unlock_irqrestore(&ub_lock, flags);
+	return ret;
+}
+
 /*
  * Downcount for deallocation. This rides on two assumptions:
  *  - once something is poisoned, its refcount cannot grow
@@ -587,6 +536,9 @@ static void ub_cleanup(struct ub_dev *sc)
 		kfree(lun);
 	}
 
+	usb_set_intfdata(sc->intf, NULL);
+	usb_put_intf(sc->intf);
+	usb_put_dev(sc->dev);
 	kfree(sc);
 }
 
@@ -674,24 +626,25 @@ static struct ub_scsi_cmd *ub_cmdq_pop(struct ub_dev *sc)
  * The request function is our main entry point
  */
 
-static void ub_bd_rq_fn(request_queue_t *q)
+static void ub_request_fn(request_queue_t *q)
 {
 	struct ub_lun *lun = q->queuedata;
 	struct request *rq;
 
 	while ((rq = elv_next_request(q)) != NULL) {
-		if (ub_bd_rq_fn_1(lun, rq) != 0) {
+		if (ub_request_fn_1(lun, rq) != 0) {
 			blk_stop_queue(q);
 			break;
 		}
 	}
 }
 
-static int ub_bd_rq_fn_1(struct ub_lun *lun, struct request *rq)
+static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
 {
 	struct ub_dev *sc = lun->udev;
 	struct ub_scsi_cmd *cmd;
-	int rc;
+	struct ub_request *urq;
+	int n_elem;
 
 	if (atomic_read(&sc->poison) || lun->changed) {
 		blkdev_dequeue_request(rq);
@@ -699,93 +652,70 @@ static int ub_bd_rq_fn_1(struct ub_lun *lun, struct request *rq)
 		return 0;
 	}
 
+	if (lun->urq.rq != NULL)
+		return -1;
 	if ((cmd = ub_get_cmd(lun)) == NULL)
 		return -1;
 	memset(cmd, 0, sizeof(struct ub_scsi_cmd));
 
 	blkdev_dequeue_request(rq);
 
+	urq = &lun->urq;
+	memset(urq, 0, sizeof(struct ub_request));
+	urq->rq = rq;
+
+	/*
+	 * get scatterlist from block layer
+	 */
+	n_elem = blk_rq_map_sg(lun->disk->queue, rq, &urq->sgv[0]);
+	if (n_elem < 0) {
+		printk(KERN_INFO "%s: failed request map (%d)\n",
+		    lun->name, n_elem); /* P3 */
+		goto drop;
+	}
+	if (n_elem > UB_MAX_REQ_SG) {	/* Paranoia */
+		printk(KERN_WARNING "%s: request with %d segments\n",
+		    lun->name, n_elem);
+		goto drop;
+	}
+	urq->nsg = n_elem;
+	sc->sg_stat[n_elem < 5 ? n_elem : 5]++;
+
 	if (blk_pc_request(rq)) {
-		rc = ub_cmd_build_packet(sc, cmd, rq);
+		ub_cmd_build_packet(sc, lun, cmd, urq);
 	} else {
-		rc = ub_cmd_build_block(sc, lun, cmd, rq);
-	}
-	if (rc != 0) {
-		ub_put_cmd(lun, cmd);
-		ub_end_rq(rq, 0);
-		return 0;
+		ub_cmd_build_block(sc, lun, cmd, urq);
 	}
 	cmd->state = UB_CMDST_INIT;
 	cmd->lun = lun;
 	cmd->done = ub_rw_cmd_done;
-	cmd->back = rq;
+	cmd->back = urq;
 
 	cmd->tag = sc->tagcnt++;
-	if ((rc = ub_submit_scsi(sc, cmd)) != 0) {
-		ub_put_cmd(lun, cmd);
-		ub_end_rq(rq, 0);
-		return 0;
-	}
+	if (ub_submit_scsi(sc, cmd) != 0)
+		goto drop;
 
 	return 0;
+
+drop:
+	ub_put_cmd(lun, cmd);
+	ub_end_rq(rq, 0);
+	return 0;
 }
 
-static int ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
-    struct ub_scsi_cmd *cmd, struct request *rq)
+static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_scsi_cmd *cmd, struct ub_request *urq)
 {
-	int ub_dir;
-#if 0 /* We use rq->buffer for now */
-	struct scatterlist *sg;
-	int n_elem;
-#endif
+	struct request *rq = urq->rq;
 	unsigned int block, nblks;
 
 	if (rq_data_dir(rq) == WRITE)
-		ub_dir = UB_DIR_WRITE;
+		cmd->dir = UB_DIR_WRITE;
 	else
-		ub_dir = UB_DIR_READ;
+		cmd->dir = UB_DIR_READ;
 
-	/*
-	 * get scatterlist from block layer
-	 */
-#if 0 /* We use rq->buffer for now */
-	sg = &cmd->sgv[0];
-	n_elem = blk_rq_map_sg(q, rq, sg);
-	if (n_elem <= 0) {
-		ub_put_cmd(lun, cmd);
-		ub_end_rq(rq, 0);
-		blk_start_queue(q);
-		return 0;		/* request with no s/g entries? */
-	}
-
-	if (n_elem != 1) {		/* Paranoia */
-		printk(KERN_WARNING "%s: request with %d segments\n",
-		    sc->name, n_elem);
-		ub_put_cmd(lun, cmd);
-		ub_end_rq(rq, 0);
-		blk_start_queue(q);
-		return 0;
-	}
-#endif
-
-	/*
-	 * XXX Unfortunately, this check does not work. It is quite possible
-	 * to get bogus non-null rq->buffer if you allow sg by mistake.
-	 */
-	if (rq->buffer == NULL) {
-		/*
-		 * This must not happen if we set the queue right.
-		 * The block level must create bounce buffers for us.
-		 */
-		static int do_print = 1;
-		if (do_print) {
-			printk(KERN_WARNING "%s: unmapped block request"
-			    " flags 0x%lx sectors %lu\n",
-			    sc->name, rq->flags, rq->nr_sectors);
-			do_print = 0;
-		}
-		return -1;
-	}
+	cmd->nsg = urq->nsg;
+	memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
 
 	/*
 	 * build the command
@@ -796,7 +726,7 @@ static int ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
 	block = rq->sector >> lun->capacity.bshift;
 	nblks = rq->nr_sectors >> lun->capacity.bshift;
 
-	cmd->cdb[0] = (ub_dir == UB_DIR_READ)? READ_10: WRITE_10;
+	cmd->cdb[0] = (cmd->dir == UB_DIR_READ)? READ_10: WRITE_10;
 	/* 10-byte uses 4 bytes of LBA: 2147483648KB, 2097152MB, 2048GB */
 	cmd->cdb[2] = block >> 24;
 	cmd->cdb[3] = block >> 16;
@@ -806,30 +736,13 @@ static int ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
 	cmd->cdb[8] = nblks;
 	cmd->cdb_len = 10;
 
-	cmd->dir = ub_dir;
-	cmd->data = rq->buffer;
 	cmd->len = rq->nr_sectors * 512;
-
-	return 0;
 }
 
-static int ub_cmd_build_packet(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
-    struct request *rq)
+static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_scsi_cmd *cmd, struct ub_request *urq)
 {
-
-	if (rq->data_len != 0 && rq->data == NULL) {
-		static int do_print = 1;
-		if (do_print) {
-			printk(KERN_WARNING "%s: unmapped packet request"
-			    " flags 0x%lx length %d\n",
-			    sc->name, rq->flags, rq->data_len);
-			do_print = 0;
-		}
-		return -1;
-	}
-
-	memcpy(&cmd->cdb, rq->cmd, rq->cmd_len);
-	cmd->cdb_len = rq->cmd_len;
+	struct request *rq = urq->rq;
 
 	if (rq->data_len == 0) {
 		cmd->dir = UB_DIR_NONE;
@@ -839,43 +752,99 @@ static int ub_cmd_build_packet(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
 		else
 			cmd->dir = UB_DIR_READ;
 	}
-	cmd->data = rq->data;
-	cmd->len = rq->data_len;
 
-	return 0;
+	cmd->nsg = urq->nsg;
+	memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
+
+	memcpy(&cmd->cdb, rq->cmd, rq->cmd_len);
+	cmd->cdb_len = rq->cmd_len;
+
+	cmd->len = rq->data_len;
 }
 
 static void ub_rw_cmd_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 {
-	struct request *rq = cmd->back;
 	struct ub_lun *lun = cmd->lun;
-	struct gendisk *disk = lun->disk;
-	request_queue_t *q = disk->queue;
+	struct ub_request *urq = cmd->back;
+	struct request *rq;
 	int uptodate;
 
-	if (blk_pc_request(rq)) {
-		/* UB_SENSE_SIZE is smaller than SCSI_SENSE_BUFFERSIZE */
-		memcpy(rq->sense, sc->top_sense, UB_SENSE_SIZE);
-		rq->sense_len = UB_SENSE_SIZE;
-	}
+	rq = urq->rq;
 
-	if (cmd->error == 0)
+	if (cmd->error == 0) {
 		uptodate = 1;
-	else
+
+		if (blk_pc_request(rq)) {
+			if (cmd->act_len >= rq->data_len)
+				rq->data_len = 0;
+			else
+				rq->data_len -= cmd->act_len;
+		}
+	} else {
 		uptodate = 0;
 
+		if (blk_pc_request(rq)) {
+			/* UB_SENSE_SIZE is smaller than SCSI_SENSE_BUFFERSIZE */
+			memcpy(rq->sense, sc->top_sense, UB_SENSE_SIZE);
+			rq->sense_len = UB_SENSE_SIZE;
+			if (sc->top_sense[0] != 0)
+				rq->errors = SAM_STAT_CHECK_CONDITION;
+			else
+				rq->errors = DID_ERROR << 16;
+		} else {
+			if (cmd->error == -EIO) {
+				if (ub_rw_cmd_retry(sc, lun, urq, cmd) == 0)
+					return;
+			}
+		}
+	}
+
+	urq->rq = NULL;
+
 	ub_put_cmd(lun, cmd);
 	ub_end_rq(rq, uptodate);
-	blk_start_queue(q);
+	blk_start_queue(lun->disk->queue);
 }
 
 static void ub_end_rq(struct request *rq, int uptodate)
 {
-	int rc;
+	end_that_request_first(rq, uptodate, rq->hard_nr_sectors);
+	end_that_request_last(rq, uptodate);
+}
+
+static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,
+    struct ub_request *urq, struct ub_scsi_cmd *cmd)
+{
+
+	if (atomic_read(&sc->poison))
+		return -ENXIO;
+
+	ub_reset_enter(sc, urq->current_try);
+
+	if (urq->current_try >= 3)
+		return -EIO;
+	urq->current_try++;
+	/* P3 */ printk("%s: dir %c len/act %d/%d "
+	    "[sense %x %02x %02x] retry %d\n",
+	    sc->name, UB_DIR_CHAR(cmd->dir), cmd->len, cmd->act_len,
+	    cmd->key, cmd->asc, cmd->ascq, urq->current_try);
 
-	rc = end_that_request_first(rq, uptodate, rq->hard_nr_sectors);
-	// assert(rc == 0);
-	end_that_request_last(rq);
+	memset(cmd, 0, sizeof(struct ub_scsi_cmd));
+	ub_cmd_build_block(sc, lun, cmd, urq);
+
+	cmd->state = UB_CMDST_INIT;
+	cmd->lun = lun;
+	cmd->done = ub_rw_cmd_done;
+	cmd->back = urq;
+
+	cmd->tag = sc->tagcnt++;
+
+#if 0 /* Wasteful */
+	return ub_submit_scsi(sc, cmd);
+#else
+	ub_cmdq_add(sc, cmd);
+	return 0;
+#endif
 }
 
 /*
@@ -886,8 +855,6 @@ static void ub_end_rq(struct request *rq, int uptodate)
  * No exceptions.
  *
  * Host is assumed locked.
- *
- * XXX We only support Bulk for the moment.
  */
 static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 {
@@ -944,7 +911,6 @@ static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 	sc->last_pipe = sc->send_bulk_pipe;
 	usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->send_bulk_pipe,
 	    bcb, US_BULK_CB_WRAP_LEN, ub_urb_complete, sc);
-	sc->work_urb.transfer_flags = URB_ASYNC_UNLINK;
 
 	/* Fill what we shouldn't be filling, because usb-storage did so. */
 	sc->work_urb.actual_length = 0;
@@ -953,7 +919,6 @@ static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 
 	if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
 		/* XXX Clear stalls */
-		printk("ub: cmd #%d start failed (%d)\n", cmd->tag, rc); /* P3 */
 		ub_complete(&sc->work_done);
 		return rc;
 	}
@@ -962,7 +927,6 @@ static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 	add_timer(&sc->work_timer);
 
 	cmd->state = UB_CMDST_CMD;
-	ub_cmdtr_state(sc, cmd);
 	return 0;
 }
 
@@ -974,9 +938,10 @@ static void ub_urb_timeout(unsigned long arg)
 	struct ub_dev *sc = (struct ub_dev *) arg;
 	unsigned long flags;
 
-	spin_lock_irqsave(&sc->lock, flags);
-	usb_unlink_urb(&sc->work_urb);
-	spin_unlock_irqrestore(&sc->lock, flags);
+	spin_lock_irqsave(sc->lock, flags);
+	if (!ub_is_completed(&sc->work_done))
+		usb_unlink_urb(&sc->work_urb);
+	spin_unlock_irqrestore(sc->lock, flags);
 }
 
 /*
@@ -999,10 +964,9 @@ static void ub_scsi_action(unsigned long _dev)
 	struct ub_dev *sc = (struct ub_dev *) _dev;
 	unsigned long flags;
 
-	spin_lock_irqsave(&sc->lock, flags);
-	del_timer(&sc->work_timer);
+	spin_lock_irqsave(sc->lock, flags);
 	ub_scsi_dispatch(sc);
-	spin_unlock_irqrestore(&sc->lock, flags);
+	spin_unlock_irqrestore(sc->lock, flags);
 }
 
 static void ub_scsi_dispatch(struct ub_dev *sc)
@@ -1010,20 +974,19 @@ static void ub_scsi_dispatch(struct ub_dev *sc)
 	struct ub_scsi_cmd *cmd;
 	int rc;
 
-	while ((cmd = ub_cmdq_peek(sc)) != NULL) {
+	while (!sc->reset && (cmd = ub_cmdq_peek(sc)) != NULL) {
 		if (cmd->state == UB_CMDST_DONE) {
 			ub_cmdq_pop(sc);
 			(*cmd->done)(sc, cmd);
 		} else if (cmd->state == UB_CMDST_INIT) {
-			ub_cmdtr_new(sc, cmd);
 			if ((rc = ub_scsi_cmd_start(sc, cmd)) == 0)
 				break;
 			cmd->error = rc;
 			cmd->state = UB_CMDST_DONE;
-			ub_cmdtr_state(sc, cmd);
 		} else {
 			if (!ub_is_completed(&sc->work_done))
 				break;
+			del_timer(&sc->work_timer);
 			ub_scsi_urb_compl(sc, cmd);
 		}
 	}
@@ -1033,12 +996,12 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 {
 	struct urb *urb = &sc->work_urb;
 	struct bulk_cs_wrap *bcs;
-	int pipe;
+	int len;
 	int rc;
 
 	if (atomic_read(&sc->poison)) {
-		/* A little too simplistic, I feel... */
-		goto Bad_End;
+		ub_state_done(sc, cmd, -ENODEV);
+		return;
 	}
 
 	if (cmd->state == UB_CMDST_CLEAR) {
@@ -1046,7 +1009,6 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 			/*
 			 * STALL while clearning STALL.
 			 * The control pipe clears itself - nothing to do.
-			 * XXX Might try to reset the device here and retry.
 			 */
 			printk(KERN_NOTICE "%s: stall on control pipe\n",
 			    sc->name);
@@ -1065,11 +1027,6 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 
 	} else if (cmd->state == UB_CMDST_CLR2STS) {
 		if (urb->status == -EPIPE) {
-			/*
-			 * STALL while clearning STALL.
-			 * The control pipe clears itself - nothing to do.
-			 * XXX Might try to reset the device here and retry.
-			 */
 			printk(KERN_NOTICE "%s: stall on control pipe\n",
 			    sc->name);
 			goto Bad_End;
@@ -1085,8 +1042,30 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 
 		ub_state_stat(sc, cmd);
 
-	} else if (cmd->state == UB_CMDST_CMD) {
+	} else if (cmd->state == UB_CMDST_CLRRS) {
 		if (urb->status == -EPIPE) {
+			printk(KERN_NOTICE "%s: stall on control pipe\n",
+			    sc->name);
+			goto Bad_End;
+		}
+
+		/*
+		 * We ignore the result for the halt clear.
+		 */
+
+		/* reset the endpoint toggle */
+		usb_settoggle(sc->dev, usb_pipeendpoint(sc->last_pipe),
+			usb_pipeout(sc->last_pipe), 0);
+
+		ub_state_stat_counted(sc, cmd);
+
+	} else if (cmd->state == UB_CMDST_CMD) {
+		switch (urb->status) {
+		case 0:
+			break;
+		case -EOVERFLOW:
+			goto Bad_End;
+		case -EPIPE:
 			rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
 			if (rc != 0) {
 				printk(KERN_NOTICE "%s: "
@@ -1096,54 +1075,29 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 				 * This is typically ENOMEM or some other such shit.
 				 * Retrying is pointless. Just do Bad End on it...
 				 */
-				goto Bad_End;
+				ub_state_done(sc, cmd, rc);
+				return;
 			}
 			cmd->state = UB_CMDST_CLEAR;
-			ub_cmdtr_state(sc, cmd);
 			return;
-		}
-		if (urb->status != 0) {
-			printk("ub: cmd #%d cmd status (%d)\n", cmd->tag, urb->status); /* P3 */
+		case -ESHUTDOWN:	/* unplug */
+		case -EILSEQ:		/* unplug timeout on uhci */
+			ub_state_done(sc, cmd, -ENODEV);
+			return;
+		default:
 			goto Bad_End;
 		}
 		if (urb->actual_length != US_BULK_CB_WRAP_LEN) {
-			printk("ub: cmd #%d xferred %d\n", cmd->tag, urb->actual_length); /* P3 */
-			/* XXX Must do reset here to unconfuse the device */
 			goto Bad_End;
 		}
 
-		if (cmd->dir == UB_DIR_NONE) {
+		if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
 			ub_state_stat(sc, cmd);
 			return;
 		}
 
-		UB_INIT_COMPLETION(sc->work_done);
-
-		if (cmd->dir == UB_DIR_READ)
-			pipe = sc->recv_bulk_pipe;
-		else
-			pipe = sc->send_bulk_pipe;
-		sc->last_pipe = pipe;
-		usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe,
-		    cmd->data, cmd->len, ub_urb_complete, sc);
-		sc->work_urb.transfer_flags = URB_ASYNC_UNLINK;
-		sc->work_urb.actual_length = 0;
-		sc->work_urb.error_count = 0;
-		sc->work_urb.status = 0;
-
-		if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
-			/* XXX Clear stalls */
-			printk("ub: data #%d submit failed (%d)\n", cmd->tag, rc); /* P3 */
-			ub_complete(&sc->work_done);
-			ub_state_done(sc, cmd, rc);
-			return;
-		}
-
-		sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT;
-		add_timer(&sc->work_timer);
-
-		cmd->state = UB_CMDST_DATA;
-		ub_cmdtr_state(sc, cmd);
+		// udelay(125);		// usb-storage has this
+		ub_data_start(sc, cmd);
 
 	} else if (cmd->state == UB_CMDST_DATA) {
 		if (urb->status == -EPIPE) {
@@ -1152,14 +1106,10 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 				printk(KERN_NOTICE "%s: "
 				    "unable to submit clear (%d)\n",
 				    sc->name, rc);
-				/*
-				 * This is typically ENOMEM or some other such shit.
-				 * Retrying is pointless. Just do Bad End on it...
-				 */
-				goto Bad_End;
+				ub_state_done(sc, cmd, rc);
+				return;
 			}
 			cmd->state = UB_CMDST_CLR2STS;
-			ub_cmdtr_state(sc, cmd);
 			return;
 		}
 		if (urb->status == -EOVERFLOW) {
@@ -1167,14 +1117,54 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 			 * A babble? Failure, but we must transfer CSW now.
 			 */
 			cmd->error = -EOVERFLOW;	/* A cheap trick... */
+			ub_state_stat(sc, cmd);
+			return;
+		}
+
+		if (cmd->dir == UB_DIR_WRITE) {
+			/*
+			 * Do not continue writes in case of a failure.
+			 * Doing so would cause sectors to be mixed up,
+			 * which is worse than sectors lost.
+			 *
+			 * We must try to read the CSW, or many devices
+			 * get confused.
+			 */
+			len = urb->actual_length;
+			if (urb->status != 0 ||
+			    len != cmd->sgv[cmd->current_sg].length) {
+				cmd->act_len += len;
+
+				cmd->error = -EIO;
+				ub_state_stat(sc, cmd);
+				return;
+			}
+
 		} else {
+			/*
+			 * If an error occurs on read, we record it, and
+			 * continue to fetch data in order to avoid bubble.
+			 *
+			 * As a small shortcut, we stop if we detect that
+			 * a CSW mixed into data.
+			 */
 			if (urb->status != 0)
-				goto Bad_End;
+				cmd->error = -EIO;
+
+			len = urb->actual_length;
+			if (urb->status != 0 ||
+			    len != cmd->sgv[cmd->current_sg].length) {
+				if ((len & 0x1FF) == US_BULK_CS_WRAP_LEN)
+					goto Bad_End;
+			}
 		}
 
-		cmd->act_len = urb->actual_length;
-		ub_cmdtr_act_len(sc, cmd);
+		cmd->act_len += urb->actual_length;
 
+		if (++cmd->current_sg < cmd->nsg) {
+			ub_data_start(sc, cmd);
+			return;
+		}
 		ub_state_stat(sc, cmd);
 
 	} else if (cmd->state == UB_CMDST_STAT) {
@@ -1184,58 +1174,53 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 				printk(KERN_NOTICE "%s: "
 				    "unable to submit clear (%d)\n",
 				    sc->name, rc);
-				/*
-				 * This is typically ENOMEM or some other such shit.
-				 * Retrying is pointless. Just do Bad End on it...
-				 */
-				goto Bad_End;
+				ub_state_done(sc, cmd, rc);
+				return;
 			}
-			cmd->state = UB_CMDST_CLEAR;
-			ub_cmdtr_state(sc, cmd);
+
+			/*
+			 * Having a stall when getting CSW is an error, so
+			 * make sure uppper levels are not oblivious to it.
+			 */
+			cmd->error = -EIO;		/* A cheap trick... */
+
+			cmd->state = UB_CMDST_CLRRS;
 			return;
 		}
+
+		/* Catch everything, including -EOVERFLOW and other nasties. */
 		if (urb->status != 0)
 			goto Bad_End;
 
 		if (urb->actual_length == 0) {
-			/*
-			 * Some broken devices add unnecessary zero-length
-			 * packets to the end of their data transfers.
-			 * Such packets show up as 0-length CSWs. If we
-			 * encounter such a thing, try to read the CSW again.
-			 */
-			if (++cmd->stat_count >= 4) {
-				printk(KERN_NOTICE "%s: unable to get CSW\n",
-				    sc->name);
-				goto Bad_End;
-			}
-			__ub_state_stat(sc, cmd);
+			ub_state_stat_counted(sc, cmd);
 			return;
 		}
 
 		/*
 		 * Check the returned Bulk protocol status.
+		 * The status block has to be validated first.
 		 */
 
 		bcs = &sc->work_bcs;
-		rc = le32_to_cpu(bcs->Residue);
-		if (rc != cmd->len - cmd->act_len) {
+
+		if (sc->signature == cpu_to_le32(0)) {
 			/*
-			 * It is all right to transfer less, the caller has
-			 * to check. But it's not all right if the device
-			 * counts disagree with our counts.
+			 * This is the first reply, so do not perform the check.
+			 * Instead, remember the signature the device uses
+			 * for future checks. But do not allow a nul.
 			 */
-			/* P3 */ printk("%s: resid %d len %d act %d\n",
-			    sc->name, rc, cmd->len, cmd->act_len);
-			goto Bad_End;
-		}
-
-#if 0
-		if (bcs->Signature != cpu_to_le32(US_BULK_CS_SIGN) &&
-		    bcs->Signature != cpu_to_le32(US_BULK_CS_OLYMPUS_SIGN)) {
-			/* Windows ignores signatures, so do we. */
+			sc->signature = bcs->Signature;
+			if (sc->signature == cpu_to_le32(0)) {
+				ub_state_stat_counted(sc, cmd);
+				return;
+			}
+		} else {
+			if (bcs->Signature != sc->signature) {
+				ub_state_stat_counted(sc, cmd);
+				return;
+			}
 		}
-#endif
 
 		if (bcs->Tag != cmd->tag) {
 			/*
@@ -1245,16 +1230,22 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 			 * commands and reply at commands we timed out before.
 			 * Without flushing these replies we loop forever.
 			 */
-			if (++cmd->stat_count >= 4) {
-				printk(KERN_NOTICE "%s: "
-				    "tag mismatch orig 0x%x reply 0x%x\n",
-				    sc->name, cmd->tag, bcs->Tag);
-				goto Bad_End;
-			}
-			__ub_state_stat(sc, cmd);
+			ub_state_stat_counted(sc, cmd);
 			return;
 		}
 
+		len = le32_to_cpu(bcs->Residue);
+		if (len != cmd->len - cmd->act_len) {
+			/*
+			 * It is all right to transfer less, the caller has
+			 * to check. But it's not all right if the device
+			 * counts disagree with our counts.
+			 */
+			/* P3 */ printk("%s: resid %d len %d act %d\n",
+			    sc->name, len, cmd->len, cmd->act_len);
+			goto Bad_End;
+		}
+
 		switch (bcs->Status) {
 		case US_BULK_STAT_OK:
 			break;
@@ -1262,18 +1253,21 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 			ub_state_sense(sc, cmd);
 			return;
 		case US_BULK_STAT_PHASE:
-			/* XXX We must reset the transport here */
 			/* P3 */ printk("%s: status PHASE\n", sc->name);
 			goto Bad_End;
 		default:
 			printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
 			    sc->name, bcs->Status);
-			goto Bad_End;
+			ub_state_done(sc, cmd, -EINVAL);
+			return;
 		}
 
 		/* Not zeroing error to preserve a babble indicator */
+		if (cmd->error != 0) {
+			ub_state_sense(sc, cmd);
+			return;
+		}
 		cmd->state = UB_CMDST_DONE;
-		ub_cmdtr_state(sc, cmd);
 		ub_cmdq_pop(sc);
 		(*cmd->done)(sc, cmd);
 
@@ -1284,7 +1278,8 @@ static void ub_scsi_urb_compl(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 		printk(KERN_WARNING "%s: "
 		    "wrong command state %d\n",
 		    sc->name, cmd->state);
-		goto Bad_End;
+		ub_state_done(sc, cmd, -EINVAL);
+		return;
 	}
 	return;
 
@@ -1292,6 +1287,43 @@ Bad_End: /* Little Excel is dead */
 	ub_state_done(sc, cmd, -EIO);
 }
 
+/*
+ * Factorization helper for the command state machine:
+ * Initiate a data segment transfer.
+ */
+static void ub_data_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+	struct scatterlist *sg = &cmd->sgv[cmd->current_sg];
+	int pipe;
+	int rc;
+
+	UB_INIT_COMPLETION(sc->work_done);
+
+	if (cmd->dir == UB_DIR_READ)
+		pipe = sc->recv_bulk_pipe;
+	else
+		pipe = sc->send_bulk_pipe;
+	sc->last_pipe = pipe;
+	usb_fill_bulk_urb(&sc->work_urb, sc->dev, pipe,
+	    page_address(sg->page) + sg->offset, sg->length,
+	    ub_urb_complete, sc);
+	sc->work_urb.actual_length = 0;
+	sc->work_urb.error_count = 0;
+	sc->work_urb.status = 0;
+
+	if ((rc = usb_submit_urb(&sc->work_urb, GFP_ATOMIC)) != 0) {
+		/* XXX Clear stalls */
+		ub_complete(&sc->work_done);
+		ub_state_done(sc, cmd, rc);
+		return;
+	}
+
+	sc->work_timer.expires = jiffies + UB_DATA_TIMEOUT;
+	add_timer(&sc->work_timer);
+
+	cmd->state = UB_CMDST_DATA;
+}
+
 /*
  * Factorization helper for the command state machine:
  * Finish the command.
@@ -1301,7 +1333,6 @@ static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
 
 	cmd->error = rc;
 	cmd->state = UB_CMDST_DONE;
-	ub_cmdtr_state(sc, cmd);
 	ub_cmdq_pop(sc);
 	(*cmd->done)(sc, cmd);
 }
@@ -1310,7 +1341,7 @@ static void ub_state_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd, int rc)
  * Factorization helper for the command state machine:
  * Submit a CSW read.
  */
-static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 {
 	int rc;
 
@@ -1319,7 +1350,6 @@ static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 	sc->last_pipe = sc->recv_bulk_pipe;
 	usb_fill_bulk_urb(&sc->work_urb, sc->dev, sc->recv_bulk_pipe,
 	    &sc->work_bcs, US_BULK_CS_WRAP_LEN, ub_urb_complete, sc);
-	sc->work_urb.transfer_flags = URB_ASYNC_UNLINK;
 	sc->work_urb.actual_length = 0;
 	sc->work_urb.error_count = 0;
 	sc->work_urb.status = 0;
@@ -1328,11 +1358,12 @@ static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 		/* XXX Clear stalls */
 		ub_complete(&sc->work_done);
 		ub_state_done(sc, cmd, rc);
-		return;
+		return -1;
 	}
 
 	sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
 	add_timer(&sc->work_timer);
+	return 0;
 }
 
 /*
@@ -1341,11 +1372,30 @@ static void __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
  */
 static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 {
-	__ub_state_stat(sc, cmd);
+
+	if (__ub_state_stat(sc, cmd) != 0)
+		return;
 
 	cmd->stat_count = 0;
 	cmd->state = UB_CMDST_STAT;
-	ub_cmdtr_state(sc, cmd);
+}
+
+/*
+ * Factorization helper for the command state machine:
+ * Submit a CSW read and go to STAT state with counter (along [C] path).
+ */
+static void ub_state_stat_counted(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
+{
+
+	if (++cmd->stat_count >= 4) {
+		ub_state_sense(sc, cmd);
+		return;
+	}
+
+	if (__ub_state_stat(sc, cmd) != 0)
+		return;
+
+	cmd->state = UB_CMDST_STAT;
 }
 
 /*
@@ -1355,6 +1405,7 @@ static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 {
 	struct ub_scsi_cmd *scmd;
+	struct scatterlist *sg;
 	int rc;
 
 	if (cmd->cdb[0] == REQUEST_SENSE) {
@@ -1363,12 +1414,17 @@ static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 	}
 
 	scmd = &sc->top_rqs_cmd;
+	memset(scmd, 0, sizeof(struct ub_scsi_cmd));
 	scmd->cdb[0] = REQUEST_SENSE;
 	scmd->cdb[4] = UB_SENSE_SIZE;
 	scmd->cdb_len = 6;
 	scmd->dir = UB_DIR_READ;
 	scmd->state = UB_CMDST_INIT;
-	scmd->data = sc->top_sense;
+	scmd->nsg = 1;
+	sg = &scmd->sgv[0];
+	sg->page = virt_to_page(sc->top_sense);
+	sg->offset = (unsigned long)sc->top_sense & (PAGE_SIZE-1);
+	sg->length = UB_SENSE_SIZE;
 	scmd->len = UB_SENSE_SIZE;
 	scmd->lun = cmd->lun;
 	scmd->done = ub_top_sense_done;
@@ -1377,7 +1433,6 @@ static void ub_state_sense(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
 	scmd->tag = sc->tagcnt++;
 
 	cmd->state = UB_CMDST_SENSE;
-	ub_cmdtr_state(sc, cmd);
 
 	ub_cmdq_insert(sc, scmd);
 	return;
@@ -1412,7 +1467,6 @@ static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
 
 	usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
 	    (unsigned char*) cr, NULL, 0, ub_urb_complete, sc);
-	sc->work_urb.transfer_flags = URB_ASYNC_UNLINK;
 	sc->work_urb.actual_length = 0;
 	sc->work_urb.error_count = 0;
 	sc->work_urb.status = 0;
@@ -1431,14 +1485,9 @@ static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
  */
 static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
 {
-	unsigned char *sense = scmd->data;
+	unsigned char *sense = sc->top_sense;
 	struct ub_scsi_cmd *cmd;
 
-	/*
-	 * Ignoring scmd->act_len, because the buffer was pre-zeroed.
-	 */
-	ub_cmdtr_sense(sc, scmd, sense);
-
 	/*
 	 * Find the command which triggered the unit attention or a check,
 	 * save the sense into it, and advance its state machine.
@@ -1460,6 +1509,9 @@ static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
 		return;
 	}
 
+	/*
+	 * Ignoring scmd->act_len, because the buffer was pre-zeroed.
+	 */
 	cmd->key = sense[2] & 0x0F;
 	cmd->asc = sense[12];
 	cmd->ascq = sense[13];
@@ -1467,6 +1519,100 @@ static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
 	ub_scsi_urb_compl(sc, cmd);
 }
 
+/*
+ * Reset management
+ * XXX Move usb_reset_device to khubd. Hogging kevent is not a good thing.
+ * XXX Make usb_sync_reset asynchronous.
+ */
+
+static void ub_reset_enter(struct ub_dev *sc, int try)
+{
+
+	if (sc->reset) {
+		/* This happens often on multi-LUN devices. */
+		return;
+	}
+	sc->reset = try + 1;
+
+#if 0 /* Not needed because the disconnect waits for us. */
+	unsigned long flags;
+	spin_lock_irqsave(&ub_lock, flags);
+	sc->openc++;
+	spin_unlock_irqrestore(&ub_lock, flags);
+#endif
+
+#if 0 /* We let them stop themselves. */
+	struct list_head *p;
+	struct ub_lun *lun;
+	list_for_each(p, &sc->luns) {
+		lun = list_entry(p, struct ub_lun, link);
+		blk_stop_queue(lun->disk->queue);
+	}
+#endif
+
+	schedule_work(&sc->reset_work);
+}
+
+static void ub_reset_task(void *arg)
+{
+	struct ub_dev *sc = arg;
+	unsigned long flags;
+	struct list_head *p;
+	struct ub_lun *lun;
+	int lkr, rc;
+
+	if (!sc->reset) {
+		printk(KERN_WARNING "%s: Running reset unrequested\n",
+		    sc->name);
+		return;
+	}
+
+	if (atomic_read(&sc->poison)) {
+		printk(KERN_NOTICE "%s: Not resetting disconnected device\n",
+		    sc->name); /* P3 This floods. Remove soon. XXX */
+	} else if ((sc->reset & 1) == 0) {
+		ub_sync_reset(sc);
+		msleep(700);	/* usb-storage sleeps 6s (!) */
+		ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
+		ub_probe_clear_stall(sc, sc->send_bulk_pipe);
+	} else if (sc->dev->actconfig->desc.bNumInterfaces != 1) {
+		printk(KERN_NOTICE "%s: Not resetting multi-interface device\n",
+		    sc->name); /* P3 This floods. Remove soon. XXX */
+	} else {
+		if ((lkr = usb_lock_device_for_reset(sc->dev, sc->intf)) < 0) {
+			printk(KERN_NOTICE
+			    "%s: usb_lock_device_for_reset failed (%d)\n",
+			    sc->name, lkr);
+		} else {
+			rc = usb_reset_device(sc->dev);
+			if (rc < 0) {
+				printk(KERN_NOTICE "%s: "
+				    "usb_lock_device_for_reset failed (%d)\n",
+				    sc->name, rc);
+			}
+
+			if (lkr)
+				usb_unlock_device(sc->dev);
+		}
+	}
+
+	/*
+	 * In theory, no commands can be running while reset is active,
+	 * so nobody can ask for another reset, and so we do not need any
+	 * queues of resets or anything. We do need a spinlock though,
+	 * to interact with block layer.
+	 */
+	spin_lock_irqsave(sc->lock, flags);
+	sc->reset = 0;
+	tasklet_schedule(&sc->tasklet);
+	list_for_each(p, &sc->luns) {
+		lun = list_entry(p, struct ub_lun, link);
+		blk_start_queue(lun->disk->queue);
+	}
+	wake_up(&sc->reset_wait);
+	spin_unlock_irqrestore(sc->lock, flags);
+}
+
 /*
  * This is called from a process context.
  */
@@ -1522,26 +1668,6 @@ static int ub_bd_open(struct inode *inode, struct file *filp)
 	sc->openc++;
 	spin_unlock_irqrestore(&ub_lock, flags);
 
-	/*
-	 * This is a workaround for a specific problem in our block layer.
-	 * In 2.6.9, register_disk duplicates the code from rescan_partitions.
-	 * However, if we do add_disk with a device which persistently reports
-	 * a changed media, add_disk calls register_disk, which does do_open,
-	 * which will call rescan_paritions for changed media. After that,
-	 * register_disk attempts to do it all again and causes double kobject
-	 * registration and a eventually an oops on module removal.
-	 *
-	 * The bottom line is, Al Viro says that we should not allow
-	 * bdev->bd_invalidated to be set when doing add_disk no matter what.
-	 */
-	if (lun->first_open) {
-		lun->first_open = 0;
-		if (lun->changed) {
-			rc = -ENOMEDIUM;
-			goto err_open;
-		}
-	}
-
 	if (lun->removable || lun->readonly)
 		check_disk_change(inode->i_bdev);
 
@@ -1680,9 +1806,8 @@ static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
 	init_completion(&compl);
 
 	rc = -ENOMEM;
-	if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
+	if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
 		goto err_alloc;
-	memset(cmd, 0, ALLOC_SIZE);
 
 	cmd->cdb[0] = TEST_UNIT_READY;
 	cmd->cdb_len = 6;
@@ -1692,11 +1817,11 @@ static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
 	cmd->done = ub_probe_done;
 	cmd->back = &compl;
 
-	spin_lock_irqsave(&sc->lock, flags);
+	spin_lock_irqsave(sc->lock, flags);
 	cmd->tag = sc->tagcnt++;
 
 	rc = ub_submit_scsi(sc, cmd);
-	spin_unlock_irqrestore(&sc->lock, flags);
+	spin_unlock_irqrestore(sc->lock, flags);
 
 	if (rc != 0) {
 		printk("ub: testing ready: submit error (%d)\n", rc); /* P3 */
@@ -1723,6 +1848,7 @@ static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
     struct ub_capacity *ret)
 {
 	struct ub_scsi_cmd *cmd;
+	struct scatterlist *sg;
 	char *p;
 	enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) + 8 };
 	unsigned long flags;
@@ -1734,26 +1860,29 @@ static int ub_sync_read_cap(struct ub_dev *sc, struct ub_lun *lun,
 	init_completion(&compl);
 
 	rc = -ENOMEM;
-	if ((cmd = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
+	if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
 		goto err_alloc;
-	memset(cmd, 0, ALLOC_SIZE);
 	p = (char *)cmd + sizeof(struct ub_scsi_cmd);
 
 	cmd->cdb[0] = 0x25;
 	cmd->cdb_len = 10;
 	cmd->dir = UB_DIR_READ;
 	cmd->state = UB_CMDST_INIT;
-	cmd->data = p;
+	cmd->nsg = 1;
+	sg = &cmd->sgv[0];
+	sg->page = virt_to_page(p);
+	sg->offset = (unsigned long)p & (PAGE_SIZE-1);
+	sg->length = 8;
 	cmd->len = 8;
 	cmd->lun = lun;
 	cmd->done = ub_probe_done;
 	cmd->back = &compl;
 
-	spin_lock_irqsave(&sc->lock, flags);
+	spin_lock_irqsave(sc->lock, flags);
 	cmd->tag = sc->tagcnt++;
 
 	rc = ub_submit_scsi(sc, cmd);
-	spin_unlock_irqrestore(&sc->lock, flags);
+	spin_unlock_irqrestore(sc->lock, flags);
 
 	if (rc != 0) {
 		printk("ub: reading capacity: submit error (%d)\n", rc); /* P3 */
@@ -1814,6 +1943,52 @@ static void ub_probe_timeout(unsigned long arg)
 	complete(cop);
 }
 
+/*
+ * Reset with a Bulk reset.
+ */
+static int ub_sync_reset(struct ub_dev *sc)
+{
+	int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
+	struct usb_ctrlrequest *cr;
+	struct completion compl;
+	struct timer_list timer;
+	int rc;
+
+	init_completion(&compl);
+
+	cr = &sc->work_cr;
+	cr->bRequestType = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
+	cr->bRequest = US_BULK_RESET_REQUEST;
+	cr->wValue = cpu_to_le16(0);
+	cr->wIndex = cpu_to_le16(ifnum);
+	cr->wLength = cpu_to_le16(0);
+
+	usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
+	    (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
+	sc->work_urb.actual_length = 0;
+	sc->work_urb.error_count = 0;
+	sc->work_urb.status = 0;
+
+	if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
+		printk(KERN_WARNING
+		     "%s: Unable to submit a bulk reset (%d)\n", sc->name, rc);
+		return rc;
+	}
+
+	init_timer(&timer);
+	timer.function = ub_probe_timeout;
+	timer.data = (unsigned long) &compl;
+	timer.expires = jiffies + UB_CTRL_TIMEOUT;
+	add_timer(&timer);
+
+	wait_for_completion(&compl);
+
+	del_timer_sync(&timer);
+	usb_kill_urb(&sc->work_urb);
+
+	return sc->work_urb.status;
+}
+
 /*
  * Get number of LUNs by the way of Bulk GetMaxLUN command.
  */
@@ -1844,17 +2019,16 @@ static int ub_sync_getmaxlun(struct ub_dev *sc)
 
 	usb_fill_control_urb(&sc->work_urb, sc->dev, sc->recv_ctrl_pipe,
 	    (unsigned char*) cr, p, 1, ub_probe_urb_complete, &compl);
-	sc->work_urb.transfer_flags = 0;
 	sc->work_urb.actual_length = 0;
 	sc->work_urb.error_count = 0;
 	sc->work_urb.status = 0;
 
 	if ((rc = usb_submit_urb(&sc->work_urb, GFP_KERNEL)) != 0) {
 		if (rc == -EPIPE) {
-			printk("%s: Stall at GetMaxLUN, using 1 LUN\n",
+			printk("%s: Stall submitting GetMaxLUN, using 1 LUN\n",
 			     sc->name); /* P3 */
 		} else {
-			printk(KERN_WARNING
+			printk(KERN_NOTICE
 			     "%s: Unable to submit GetMaxLUN (%d)\n",
 			     sc->name, rc);
 		}
@@ -1872,6 +2046,18 @@ static int ub_sync_getmaxlun(struct ub_dev *sc)
 	del_timer_sync(&timer);
 	usb_kill_urb(&sc->work_urb);
 
+	if ((rc = sc->work_urb.status) < 0) {
+		if (rc == -EPIPE) {
+			printk("%s: Stall at GetMaxLUN, using 1 LUN\n",
+			     sc->name); /* P3 */
+		} else {
+			printk(KERN_NOTICE
+			     "%s: Error at GetMaxLUN (%d)\n",
+			     sc->name, rc);
+		}
+		goto err_io;
+	}
+
 	if (sc->work_urb.actual_length != 1) {
 		printk("%s: GetMaxLUN returned %d bytes\n", sc->name,
 		    sc->work_urb.actual_length); /* P3 */
@@ -1892,6 +2078,7 @@ static int ub_sync_getmaxlun(struct ub_dev *sc)
 	kfree(p);
 	return nluns;
 
+err_io:
 err_submit:
 	kfree(p);
 err_alloc:
@@ -1924,7 +2111,6 @@ static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe)
 
 	usb_fill_control_urb(&sc->work_urb, sc->dev, sc->send_ctrl_pipe,
 	    (unsigned char*) cr, NULL, 0, ub_probe_urb_complete, &compl);
-	sc->work_urb.transfer_flags = 0;
 	sc->work_urb.actual_length = 0;
 	sc->work_urb.error_count = 0;
 	sc->work_urb.status = 0;
@@ -1986,7 +2172,7 @@ static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev,
 	if (ep_in == NULL || ep_out == NULL) {
 		printk(KERN_NOTICE "%s: failed endpoint check\n",
 		    sc->name);
-		return -EIO;
+		return -ENODEV;
 	}
 
 	/* Calculate and store the pipe values */
@@ -2012,15 +2198,19 @@ static int ub_probe(struct usb_interface *intf,
 	int rc;
 	int i;
 
+	if (usb_usual_check_type(dev_id, USB_US_TYPE_UB))
+		return -ENXIO;
+
 	rc = -ENOMEM;
-	if ((sc = kmalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
+	if ((sc = kzalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
 		goto err_core;
-	memset(sc, 0, sizeof(struct ub_dev));
-	spin_lock_init(&sc->lock);
+	sc->lock = ub_next_lock();
 	INIT_LIST_HEAD(&sc->luns);
 	usb_init_urb(&sc->work_urb);
 	tasklet_init(&sc->tasklet, ub_scsi_action, (unsigned long)sc);
 	atomic_set(&sc->poison, 0);
+	INIT_WORK(&sc->reset_work, ub_reset_task, sc);
+	init_waitqueue_head(&sc->reset_wait);
 
 	init_timer(&sc->work_timer);
 	sc->work_timer.data = (unsigned long) sc;
@@ -2034,17 +2224,20 @@ static int ub_probe(struct usb_interface *intf,
 	// sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
 	usb_set_intfdata(intf, sc);
 	usb_get_dev(sc->dev);
-	// usb_get_intf(sc->intf);	/* Do we need this? */
+	/*
+	 * Since we give the interface struct to the block level through
+	 * disk->driverfs_dev, we have to pin it. Otherwise, block_uevent
+	 * oopses on close after a disconnect (kernels 2.6.16 and up).
+	 */
+	usb_get_intf(sc->intf);
 
 	snprintf(sc->name, 12, DRV_NAME "(%d.%d)",
 	    sc->dev->bus->busnum, sc->dev->devnum);
 
 	/* XXX Verify that we can handle the device (from descriptors) */
 
-	ub_get_pipes(sc, sc->dev, intf);
-
-	if (device_create_file(&sc->intf->dev, &dev_attr_diag) != 0)
-		goto err_diag;
+	if (ub_get_pipes(sc, sc->dev, intf) != 0)
+		goto err_dev_desc;
 
 	/*
 	 * At this point, all USB initialization is done, do upper layer.
@@ -2057,8 +2250,10 @@ static int ub_probe(struct usb_interface *intf,
 	 * This is needed to clear toggles. It is a problem only if we do
 	 * `rmmod ub && modprobe ub` without disconnects, but we like that.
 	 */
+#if 0 /* iPod Mini fails if we do this (big white iPod works) */
 	ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
 	ub_probe_clear_stall(sc, sc->send_bulk_pipe);
+#endif
 
 	/*
 	 * The way this is used by the startup code is a little specific.
@@ -2083,19 +2278,8 @@ static int ub_probe(struct usb_interface *intf,
 
 	nluns = 1;
 	for (i = 0; i < 3; i++) {
-		if ((rc = ub_sync_getmaxlun(sc)) < 0) {
-			/* 
-			 * Some devices (i.e. Iomega Zip100) need this --
-			 * apparently the bulk pipes get STALLed when the
-			 * GetMaxLUN request is processed.
-			 * XXX I have a ZIP-100, verify it does this.
-			 */
-			if (rc == -EPIPE) {
-				ub_probe_clear_stall(sc, sc->recv_bulk_pipe);
-				ub_probe_clear_stall(sc, sc->send_bulk_pipe);
-			}
+		if ((rc = ub_sync_getmaxlun(sc)) < 0)
 			break;
-		}
 		if (rc != 0) {
 			nluns = rc;
 			break;
@@ -2108,10 +2292,9 @@ static int ub_probe(struct usb_interface *intf,
 	}
 	return 0;
 
-	/* device_remove_file(&sc->intf->dev, &dev_attr_diag); */
-err_diag:
+err_dev_desc:
 	usb_set_intfdata(intf, NULL);
-	// usb_put_intf(sc->intf);
+	usb_put_intf(sc->intf);
 	usb_put_dev(sc->dev);
 	kfree(sc);
 err_core:
@@ -2126,9 +2309,8 @@ static int ub_probe_lun(struct ub_dev *sc, int lnum)
 	int rc;
 
 	rc = -ENOMEM;
-	if ((lun = kmalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
+	if ((lun = kzalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
 		goto err_alloc;
-	memset(lun, 0, sizeof(struct ub_lun));
 	lun->num = lnum;
 
 	rc = -ENOSR;
@@ -2143,24 +2325,23 @@ static int ub_probe_lun(struct ub_dev *sc, int lnum)
 
 	lun->removable = 1;		/* XXX Query this from the device */
 	lun->changed = 1;		/* ub_revalidate clears only */
-	lun->first_open = 1;
 	ub_revalidate(sc, lun);
 
 	rc = -ENOMEM;
-	if ((disk = alloc_disk(UB_MINORS_PER_MAJOR)) == NULL)
+	if ((disk = alloc_disk(UB_PARTS_PER_LUN)) == NULL)
 		goto err_diskalloc;
 
 	lun->disk = disk;
 	sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a');
 	sprintf(disk->devfs_name, DEVFS_NAME "/%c", lun->id + 'a');
 	disk->major = UB_MAJOR;
-	disk->first_minor = lun->id * UB_MINORS_PER_MAJOR;
+	disk->first_minor = lun->id * UB_PARTS_PER_LUN;
 	disk->fops = &ub_bd_fops;
 	disk->private_data = lun;
-	disk->driverfs_dev = &sc->intf->dev;	/* XXX Many to one ok? */
+	disk->driverfs_dev = &sc->intf->dev;
 
 	rc = -ENOMEM;
-	if ((q = blk_init_queue(ub_bd_rq_fn, &sc->lock)) == NULL)
+	if ((q = blk_init_queue(ub_request_fn, sc->lock)) == NULL)
 		goto err_blkqinit;
 
 	disk->queue = q;
@@ -2217,6 +2398,11 @@ static void ub_disconnect(struct usb_interface *intf)
 	 */
 	atomic_set(&sc->poison, 1);
 
+	/*
+	 * Wait for reset to end, if any.
+	 */
+	wait_event(sc->reset_wait, !sc->reset);
+
 	/*
 	 * Blow away queued commands.
 	 *
@@ -2226,14 +2412,13 @@ static void ub_disconnect(struct usb_interface *intf)
 	 * and the whole queue drains. So, we just use this code to
 	 * print warnings.
 	 */
-	spin_lock_irqsave(&sc->lock, flags);
+	spin_lock_irqsave(sc->lock, flags);
 	{
 		struct ub_scsi_cmd *cmd;
 		int cnt = 0;
-		while ((cmd = ub_cmdq_pop(sc)) != NULL) {
+		while ((cmd = ub_cmdq_peek(sc)) != NULL) {
 			cmd->error = -ENOTCONN;
 			cmd->state = UB_CMDST_DONE;
-			ub_cmdtr_state(sc, cmd);
 			ub_cmdq_pop(sc);
 			(*cmd->done)(sc, cmd);
 			cnt++;
@@ -2243,7 +2428,7 @@ static void ub_disconnect(struct usb_interface *intf)
 			    "%d was queued after shutdown\n", sc->name, cnt);
 		}
 	}
-	spin_unlock_irqrestore(&sc->lock, flags);
+	spin_unlock_irqrestore(sc->lock, flags);
 
 	/*
 	 * Unregister the upper layer.
@@ -2262,19 +2447,15 @@ static void ub_disconnect(struct usb_interface *intf)
 	}
 
 	/*
-	 * Taking a lock on a structure which is about to be freed
-	 * is very nonsensual. Here it is largely a way to do a debug freeze,
-	 * and a bracket which shows where the nonsensual code segment ends.
-	 *
 	 * Testing for -EINPROGRESS is always a bug, so we are bending
 	 * the rules a little.
 	 */
-	spin_lock_irqsave(&sc->lock, flags);
+	spin_lock_irqsave(sc->lock, flags);
 	if (sc->work_urb.status == -EINPROGRESS) {	/* janitors: ignore */
 		printk(KERN_WARNING "%s: "
 		    "URB is active after disconnect\n", sc->name);
 	}
-	spin_unlock_irqrestore(&sc->lock, flags);
+	spin_unlock_irqrestore(sc->lock, flags);
 
 	/*
 	 * There is virtually no chance that other CPU runs times so long
@@ -2288,18 +2469,10 @@ static void ub_disconnect(struct usb_interface *intf)
 	 * and no URBs left in transit.
 	 */
 
-	device_remove_file(&sc->intf->dev, &dev_attr_diag);
-	usb_set_intfdata(intf, NULL);
-	// usb_put_intf(sc->intf);
-	sc->intf = NULL;
-	usb_put_dev(sc->dev);
-	sc->dev = NULL;
-
 	ub_put(sc);
 }
 
 static struct usb_driver ub_driver = {
-	.owner =	THIS_MODULE,
 	.name =		"ub",
 	.probe =	ub_probe,
 	.disconnect =	ub_disconnect,
@@ -2309,9 +2482,10 @@ static struct usb_driver ub_driver = {
 static int __init ub_init(void)
 {
 	int rc;
+	int i;
 
-	/* P3 */ printk("ub: sizeof ub_scsi_cmd %zu ub_dev %zu ub_lun %zu\n",
-			sizeof(struct ub_scsi_cmd), sizeof(struct ub_dev), sizeof(struct ub_lun));
+	for (i = 0; i < UB_QLOCK_NUM; i++)
+		spin_lock_init(&ub_qlockv[i]);
 
 	if ((rc = register_blkdev(UB_MAJOR, DRV_NAME)) != 0)
 		goto err_regblkdev;
@@ -2320,6 +2494,7 @@ static int __init ub_init(void)
 	if ((rc = usb_register(&ub_driver)) != 0)
 		goto err_register;
 
+	usb_usual_set_present(USB_US_TYPE_UB);
 	return 0;
 
 err_register:
@@ -2335,6 +2510,7 @@ static void __exit ub_exit(void)
 
 	devfs_remove(DEVFS_NAME);
 	unregister_blkdev(UB_MAJOR, DRV_NAME);
+	usb_usual_clear_present(USB_US_TYPE_UB);
 }
 
 module_init(ub_init);