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linux/drivers/block/ub.c
Pete Zaitcev 643616e678 ub: Bind to first endpoint, not to last 
The usb-storage switched to binding to first endpoint recently. Apparently,
there are devices out there with extra endpoints. It is perfectly legal.

Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-04-27 13:28:34 -07:00

2485 lines
62 KiB
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/*
* The low performance USB storage driver (ub).
*
* Copyright (c) 1999, 2000 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
* Copyright (C) 2004 Pete Zaitcev (zaitcev@yahoo.com)
*
* This work is a part of Linux kernel, is derived from it,
* and is not licensed separately. See file COPYING for details.
*
* TODO (sorted by decreasing priority)
* -- 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)
* -- verify the 13 conditions and do bulk resets
* -- 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
* -- Resove XXX's
* -- 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/timer.h>
#include <scsi/scsi.h>
#define DRV_NAME "ub"
#define UB_MAJOR 180
/*
* 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 !
* +--------+
*/
/*
* This many LUNs per USB device.
* Every one of them takes a host, see UB_MAX_HOSTS.
*/
#define UB_MAX_LUNS 9
/*
*/
#define UB_PARTS_PER_LUN 8
#define UB_MAX_CDB_SIZE 16 /* Corresponds to Bulk */
#define UB_SENSE_SIZE 18
/*
*/
/* command block wrapper */
struct bulk_cb_wrap {
__le32 Signature; /* contains 'USBC' */
u32 Tag; /* unique per command id */
__le32 DataTransferLength; /* size of data */
u8 Flags; /* direction in bit 0 */
u8 Lun; /* LUN */
u8 Length; /* of of the CDB */
u8 CDB[UB_MAX_CDB_SIZE]; /* max command */
};
#define US_BULK_CB_WRAP_LEN 31
#define US_BULK_CB_SIGN 0x43425355 /*spells out USBC */
#define US_BULK_FLAG_IN 1
#define US_BULK_FLAG_OUT 0
/* command status wrapper */
struct bulk_cs_wrap {
__le32 Signature; /* should = 'USBS' */
u32 Tag; /* same as original command */
__le32 Residue; /* amount not transferred */
u8 Status; /* see below */
};
#define US_BULK_CS_WRAP_LEN 13
#define US_BULK_CS_SIGN 0x53425355 /* spells out 'USBS' */
#define US_BULK_STAT_OK 0
#define US_BULK_STAT_FAIL 1
#define US_BULK_STAT_PHASE 2
/* bulk-only class specific requests */
#define US_BULK_RESET_REQUEST 0xff
#define US_BULK_GET_MAX_LUN 0xfe
/*
*/
struct ub_dev;
#define UB_MAX_REQ_SG 9 /* cdrecord requires 32KB and maybe a header */
#define UB_MAX_SECTORS 64
/*
* A second is more than enough for a 32K transfer (UB_MAX_SECTORS)
* even if a webcam hogs the bus, but some devices need time to spin up.
*/
#define UB_URB_TIMEOUT (HZ*2)
#define UB_DATA_TIMEOUT (HZ*5) /* ZIP does spin-ups in the data phase */
#define UB_STAT_TIMEOUT (HZ*5) /* Same spinups and eject for a dataless cmd. */
#define UB_CTRL_TIMEOUT (HZ/2) /* 500ms ought to be enough to clear a stall */
/*
* An instance of a SCSI command in transit.
*/
#define UB_DIR_NONE 0
#define UB_DIR_READ 1
#define UB_DIR_ILLEGAL2 2
#define UB_DIR_WRITE 3
#define UB_DIR_CHAR(c) (((c)==UB_DIR_WRITE)? 'w': \
(((c)==UB_DIR_READ)? 'r': 'n'))
enum ub_scsi_cmd_state {
UB_CMDST_INIT, /* Initial state */
UB_CMDST_CMD, /* Command submitted */
UB_CMDST_DATA, /* Data phase */
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 */
};
struct ub_scsi_cmd {
unsigned char cdb[UB_MAX_CDB_SIZE];
unsigned char cdb_len;
unsigned char dir; /* 0 - none, 1 - read, 3 - write. */
enum ub_scsi_cmd_state state;
unsigned int tag;
struct ub_scsi_cmd *next;
int error; /* Return code - valid upon done */
unsigned int act_len; /* Return size */
unsigned char key, asc, ascq; /* May be valid if error==-EIO */
int stat_count; /* Retries getting status. */
unsigned int len; /* Requested length */
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 {
unsigned long nsec; /* Linux size - 512 byte sectors */
unsigned int bsize; /* Linux hardsect_size */
unsigned int bshift; /* Shift between 512 and hard sects */
};
/*
* This is a direct take-off from linux/include/completion.h
* The difference is that I do not wait on this thing, just poll.
* When I want to wait (ub_probe), I just use the stock completion.
*
* Note that INIT_COMPLETION takes no lock. It is correct. But why
* in the bloody hell that thing takes struct instead of pointer to struct
* is quite beyond me. I just copied it from the stock completion.
*/
struct ub_completion {
unsigned int done;
spinlock_t lock;
};
static inline void ub_init_completion(struct ub_completion *x)
{
x->done = 0;
spin_lock_init(&x->lock);
}
#define UB_INIT_COMPLETION(x) ((x).done = 0)
static void ub_complete(struct ub_completion *x)
{
unsigned long flags;
spin_lock_irqsave(&x->lock, flags);
x->done++;
spin_unlock_irqrestore(&x->lock, flags);
}
static int ub_is_completed(struct ub_completion *x)
{
unsigned long flags;
int ret;
spin_lock_irqsave(&x->lock, flags);
ret = x->done;
spin_unlock_irqrestore(&x->lock, flags);
return ret;
}
/*
*/
struct ub_scsi_cmd_queue {
int qlen, qmax;
struct ub_scsi_cmd *head, *tail;
};
/*
* The block device instance (one per LUN).
*/
struct ub_lun {
struct ub_dev *udev;
struct list_head link;
struct gendisk *disk;
int id; /* Host index */
int num; /* LUN number */
char name[16];
int changed; /* Media was changed */
int removable;
int readonly;
struct ub_request urq;
/* Use Ingo's mempool if or when we have more than one command. */
/*
* Currently we never need more than one command for the whole device.
* However, giving every LUN a command is a cheap and automatic way
* to enforce fairness between them.
*/
int cmda[1];
struct ub_scsi_cmd cmdv[1];
struct ub_capacity capacity;
};
/*
* The USB device instance.
*/
struct ub_dev {
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;
struct usb_interface *intf;
struct list_head luns;
unsigned int send_bulk_pipe; /* cached pipe values */
unsigned int recv_bulk_pipe;
unsigned int send_ctrl_pipe;
unsigned int recv_ctrl_pipe;
struct tasklet_struct tasklet;
struct ub_scsi_cmd_queue cmd_queue;
struct ub_scsi_cmd top_rqs_cmd; /* REQUEST SENSE */
unsigned char top_sense[UB_SENSE_SIZE];
struct ub_completion work_done;
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 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_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, unsigned int status);
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);
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 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(struct work_struct *work);
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_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(),
* and the array disappears the next day. However, the number of
* hosts has something to do with the naming and /proc/partitions.
* This has to be thought out in detail before changing.
* If UB_MAX_HOST was 1000, we'd use a bitmap. Or a better data structure.
*/
#define UB_MAX_HOSTS 26
static char ub_hostv[UB_MAX_HOSTS];
#define UB_QLOCK_NUM 5
static spinlock_t ub_qlockv[UB_QLOCK_NUM];
static int ub_qlock_next = 0;
static DEFINE_SPINLOCK(ub_lock); /* Locks globals and ->openc */
/*
* The id allocator.
*
* This also stores the host for indexing by minor, which is somewhat dirty.
*/
static int ub_id_get(void)
{
unsigned long flags;
int i;
spin_lock_irqsave(&ub_lock, flags);
for (i = 0; i < UB_MAX_HOSTS; i++) {
if (ub_hostv[i] == 0) {
ub_hostv[i] = 1;
spin_unlock_irqrestore(&ub_lock, flags);
return i;
}
}
spin_unlock_irqrestore(&ub_lock, flags);
return -1;
}
static void ub_id_put(int id)
{
unsigned long flags;
if (id < 0 || id >= UB_MAX_HOSTS) {
printk(KERN_ERR DRV_NAME ": bad host ID %d\n", id);
return;
}
spin_lock_irqsave(&ub_lock, flags);
if (ub_hostv[id] == 0) {
spin_unlock_irqrestore(&ub_lock, flags);
printk(KERN_ERR DRV_NAME ": freeing free host ID %d\n", id);
return;
}
ub_hostv[id] = 0;
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
* - opens cannot happen at this time (del_gendisk was done)
* If the above is true, we can drop the lock, which we need for
* blk_cleanup_queue(): the silly thing may attempt to sleep.
* [Actually, it never needs to sleep for us, but it calls might_sleep()]
*/
static void ub_put(struct ub_dev *sc)
{
unsigned long flags;
spin_lock_irqsave(&ub_lock, flags);
--sc->openc;
if (sc->openc == 0 && atomic_read(&sc->poison)) {
spin_unlock_irqrestore(&ub_lock, flags);
ub_cleanup(sc);
} else {
spin_unlock_irqrestore(&ub_lock, flags);
}
}
/*
* Final cleanup and deallocation.
*/
static void ub_cleanup(struct ub_dev *sc)
{
struct list_head *p;
struct ub_lun *lun;
request_queue_t *q;
while (!list_empty(&sc->luns)) {
p = sc->luns.next;
lun = list_entry(p, struct ub_lun, link);
list_del(p);
/* I don't think queue can be NULL. But... Stolen from sx8.c */
if ((q = lun->disk->queue) != NULL)
blk_cleanup_queue(q);
/*
* If we zero disk->private_data BEFORE put_disk, we have
* to check for NULL all over the place in open, release,
* check_media and revalidate, because the block level
* semaphore is well inside the put_disk.
* But we cannot zero after the call, because *disk is gone.
* The sd.c is blatantly racy in this area.
*/
/* disk->private_data = NULL; */
put_disk(lun->disk);
lun->disk = NULL;
ub_id_put(lun->id);
kfree(lun);
}
usb_set_intfdata(sc->intf, NULL);
usb_put_intf(sc->intf);
usb_put_dev(sc->dev);
kfree(sc);
}
/*
* The "command allocator".
*/
static struct ub_scsi_cmd *ub_get_cmd(struct ub_lun *lun)
{
struct ub_scsi_cmd *ret;
if (lun->cmda[0])
return NULL;
ret = &lun->cmdv[0];
lun->cmda[0] = 1;
return ret;
}
static void ub_put_cmd(struct ub_lun *lun, struct ub_scsi_cmd *cmd)
{
if (cmd != &lun->cmdv[0]) {
printk(KERN_WARNING "%s: releasing a foreign cmd %p\n",
lun->name, cmd);
return;
}
if (!lun->cmda[0]) {
printk(KERN_WARNING "%s: releasing a free cmd\n", lun->name);
return;
}
lun->cmda[0] = 0;
}
/*
* The command queue.
*/
static void ub_cmdq_add(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
if (t->qlen++ == 0) {
t->head = cmd;
t->tail = cmd;
} else {
t->tail->next = cmd;
t->tail = cmd;
}
if (t->qlen > t->qmax)
t->qmax = t->qlen;
}
static void ub_cmdq_insert(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
if (t->qlen++ == 0) {
t->head = cmd;
t->tail = cmd;
} else {
cmd->next = t->head;
t->head = cmd;
}
if (t->qlen > t->qmax)
t->qmax = t->qlen;
}
static struct ub_scsi_cmd *ub_cmdq_pop(struct ub_dev *sc)
{
struct ub_scsi_cmd_queue *t = &sc->cmd_queue;
struct ub_scsi_cmd *cmd;
if (t->qlen == 0)
return NULL;
if (--t->qlen == 0)
t->tail = NULL;
cmd = t->head;
t->head = cmd->next;
cmd->next = NULL;
return cmd;
}
#define ub_cmdq_peek(sc) ((sc)->cmd_queue.head)
/*
* The request function is our main entry point
*/
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_request_fn_1(lun, rq) != 0) {
blk_stop_queue(q);
break;
}
}
}
static int ub_request_fn_1(struct ub_lun *lun, struct request *rq)
{
struct ub_dev *sc = lun->udev;
struct ub_scsi_cmd *cmd;
struct ub_request *urq;
int n_elem;
if (atomic_read(&sc->poison)) {
blkdev_dequeue_request(rq);
ub_end_rq(rq, DID_NO_CONNECT << 16);
return 0;
}
if (lun->changed && !blk_pc_request(rq)) {
blkdev_dequeue_request(rq);
ub_end_rq(rq, SAM_STAT_CHECK_CONDITION);
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) {
/* Impossible, because blk_rq_map_sg should not hit ENOMEM. */
printk(KERN_INFO "%s: failed request map (%d)\n",
lun->name, n_elem);
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)) {
ub_cmd_build_packet(sc, lun, cmd, urq);
} else {
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 (ub_submit_scsi(sc, cmd) != 0)
goto drop;
return 0;
drop:
ub_put_cmd(lun, cmd);
ub_end_rq(rq, DID_ERROR << 16);
return 0;
}
static void ub_cmd_build_block(struct ub_dev *sc, struct ub_lun *lun,
struct ub_scsi_cmd *cmd, struct ub_request *urq)
{
struct request *rq = urq->rq;
unsigned int block, nblks;
if (rq_data_dir(rq) == WRITE)
cmd->dir = UB_DIR_WRITE;
else
cmd->dir = UB_DIR_READ;
cmd->nsg = urq->nsg;
memcpy(cmd->sgv, urq->sgv, sizeof(struct scatterlist) * cmd->nsg);
/*
* build the command
*
* The call to blk_queue_hardsect_size() guarantees that request
* is aligned, but it is given in terms of 512 byte units, always.
*/
block = rq->sector >> lun->capacity.bshift;
nblks = rq->nr_sectors >> lun->capacity.bshift;
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;
cmd->cdb[4] = block >> 8;
cmd->cdb[5] = block;
cmd->cdb[7] = nblks >> 8;
cmd->cdb[8] = nblks;
cmd->cdb_len = 10;
cmd->len = rq->nr_sectors * 512;
}
static void ub_cmd_build_packet(struct ub_dev *sc, struct ub_lun *lun,
struct ub_scsi_cmd *cmd, struct ub_request *urq)
{
struct request *rq = urq->rq;
if (rq->data_len == 0) {
cmd->dir = UB_DIR_NONE;
} else {
if (rq_data_dir(rq) == WRITE)
cmd->dir = UB_DIR_WRITE;
else
cmd->dir = UB_DIR_READ;
}
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 ub_lun *lun = cmd->lun;
struct ub_request *urq = cmd->back;
struct request *rq;
unsigned int scsi_status;
rq = urq->rq;
if (cmd->error == 0) {
if (blk_pc_request(rq)) {
if (cmd->act_len >= rq->data_len)
rq->data_len = 0;
else
rq->data_len -= cmd->act_len;
}
scsi_status = 0;
} else {
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)
scsi_status = SAM_STAT_CHECK_CONDITION;
else
scsi_status = DID_ERROR << 16;
} else {
if (cmd->error == -EIO) {
if (ub_rw_cmd_retry(sc, lun, urq, cmd) == 0)
return;
}
scsi_status = SAM_STAT_CHECK_CONDITION;
}
}
urq->rq = NULL;
ub_put_cmd(lun, cmd);
ub_end_rq(rq, scsi_status);
blk_start_queue(lun->disk->queue);
}
static void ub_end_rq(struct request *rq, unsigned int scsi_status)
{
int uptodate;
if (scsi_status == 0) {
uptodate = 1;
} else {
uptodate = 0;
rq->errors = scsi_status;
}
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++;
/* Remove this if anyone complains of flooding. */
printk(KERN_DEBUG "%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);
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
}
/*
* Submit a regular SCSI operation (not an auto-sense).
*
* The Iron Law of Good Submit Routine is:
* Zero return - callback is done, Nonzero return - callback is not done.
* No exceptions.
*
* Host is assumed locked.
*/
static int ub_submit_scsi(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
if (cmd->state != UB_CMDST_INIT ||
(cmd->dir != UB_DIR_NONE && cmd->len == 0)) {
return -EINVAL;
}
ub_cmdq_add(sc, cmd);
/*
* We can call ub_scsi_dispatch(sc) right away here, but it's a little
* safer to jump to a tasklet, in case upper layers do something silly.
*/
tasklet_schedule(&sc->tasklet);
return 0;
}
/*
* Submit the first URB for the queued command.
* This function does not deal with queueing in any way.
*/
static int ub_scsi_cmd_start(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
struct bulk_cb_wrap *bcb;
int rc;
bcb = &sc->work_bcb;
/*
* ``If the allocation length is eighteen or greater, and a device
* server returns less than eithteen bytes of data, the application
* client should assume that the bytes not transferred would have been
* zeroes had the device server returned those bytes.''
*
* We zero sense for all commands so that when a packet request
* fails it does not return a stale sense.
*/
memset(&sc->top_sense, 0, UB_SENSE_SIZE);
/* set up the command wrapper */
bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
bcb->Tag = cmd->tag; /* Endianness is not important */
bcb->DataTransferLength = cpu_to_le32(cmd->len);
bcb->Flags = (cmd->dir == UB_DIR_READ) ? 0x80 : 0;
bcb->Lun = (cmd->lun != NULL) ? cmd->lun->num : 0;
bcb->Length = cmd->cdb_len;
/* copy the command payload */
memcpy(bcb->CDB, cmd->cdb, UB_MAX_CDB_SIZE);
UB_INIT_COMPLETION(sc->work_done);
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);
/* Fill what we shouldn't be filling, because usb-storage did so. */
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);
return rc;
}
sc->work_timer.expires = jiffies + UB_URB_TIMEOUT;
add_timer(&sc->work_timer);
cmd->state = UB_CMDST_CMD;
return 0;
}
/*
* Timeout handler.
*/
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);
if (!ub_is_completed(&sc->work_done))
usb_unlink_urb(&sc->work_urb);
spin_unlock_irqrestore(sc->lock, flags);
}
/*
* Completion routine for the work URB.
*
* This can be called directly from usb_submit_urb (while we have
* the sc->lock taken) and from an interrupt (while we do NOT have
* the sc->lock taken). Therefore, bounce this off to a tasklet.
*/
static void ub_urb_complete(struct urb *urb)
{
struct ub_dev *sc = urb->context;
ub_complete(&sc->work_done);
tasklet_schedule(&sc->tasklet);
}
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);
ub_scsi_dispatch(sc);
spin_unlock_irqrestore(sc->lock, flags);
}
static void ub_scsi_dispatch(struct ub_dev *sc)
{
struct ub_scsi_cmd *cmd;
int rc;
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) {
if ((rc = ub_scsi_cmd_start(sc, cmd)) == 0)
break;
cmd->error = rc;
cmd->state = UB_CMDST_DONE;
} else {
if (!ub_is_completed(&sc->work_done))
break;
del_timer(&sc->work_timer);
ub_scsi_urb_compl(sc, cmd);
}
}
}
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 len;
int rc;
if (atomic_read(&sc->poison)) {
ub_state_done(sc, cmd, -ENODEV);
return;
}
if (cmd->state == UB_CMDST_CLEAR) {
if (urb->status == -EPIPE) {
/*
* STALL while clearning STALL.
* The control pipe clears itself - nothing to do.
*/
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_sense(sc, cmd);
} else if (cmd->state == UB_CMDST_CLR2STS) {
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(sc, 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: "
"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...
*/
ub_state_done(sc, cmd, rc);
return;
}
cmd->state = UB_CMDST_CLEAR;
return;
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) {
goto Bad_End;
}
if (cmd->dir == UB_DIR_NONE || cmd->nsg < 1) {
ub_state_stat(sc, cmd);
return;
}
// udelay(125); // usb-storage has this
ub_data_start(sc, cmd);
} else if (cmd->state == UB_CMDST_DATA) {
if (urb->status == -EPIPE) {
rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
if (rc != 0) {
printk(KERN_NOTICE "%s: "
"unable to submit clear (%d)\n",
sc->name, rc);
ub_state_done(sc, cmd, rc);
return;
}
cmd->state = UB_CMDST_CLR2STS;
return;
}
if (urb->status == -EOVERFLOW) {
/*
* 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)
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;
if (++cmd->current_sg < cmd->nsg) {
ub_data_start(sc, cmd);
return;
}
ub_state_stat(sc, cmd);
} else if (cmd->state == UB_CMDST_STAT) {
if (urb->status == -EPIPE) {
rc = ub_submit_clear_stall(sc, cmd, sc->last_pipe);
if (rc != 0) {
printk(KERN_NOTICE "%s: "
"unable to submit clear (%d)\n",
sc->name, rc);
ub_state_done(sc, cmd, rc);
return;
}
/*
* 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) {
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;
if (sc->signature == cpu_to_le32(0)) {
/*
* 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.
*/
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;
}
}
if (bcs->Tag != cmd->tag) {
/*
* This usually happens when we disagree with the
* device's microcode about something. For instance,
* a few of them throw this after timeouts. They buffer
* commands and reply at commands we timed out before.
* Without flushing these replies we loop forever.
*/
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.
*/
goto Bad_End;
}
switch (bcs->Status) {
case US_BULK_STAT_OK:
break;
case US_BULK_STAT_FAIL:
ub_state_sense(sc, cmd);
return;
case US_BULK_STAT_PHASE:
goto Bad_End;
default:
printk(KERN_INFO "%s: unknown CSW status 0x%x\n",
sc->name, bcs->Status);
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_cmdq_pop(sc);
(*cmd->done)(sc, cmd);
} else if (cmd->state == UB_CMDST_SENSE) {
ub_state_done(sc, cmd, -EIO);
} else {
printk(KERN_WARNING "%s: "
"wrong command state %d\n",
sc->name, cmd->state);
ub_state_done(sc, cmd, -EINVAL);
return;
}
return;
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.
*/
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_cmdq_pop(sc);
(*cmd->done)(sc, cmd);
}
/*
* Factorization helper for the command state machine:
* Submit a CSW read.
*/
static int __ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
int rc;
UB_INIT_COMPLETION(sc->work_done);
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.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 -1;
}
sc->work_timer.expires = jiffies + UB_STAT_TIMEOUT;
add_timer(&sc->work_timer);
return 0;
}
/*
* Factorization helper for the command state machine:
* Submit a CSW read and go to STAT state.
*/
static void ub_state_stat(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
if (__ub_state_stat(sc, cmd) != 0)
return;
cmd->stat_count = 0;
cmd->state = UB_CMDST_STAT;
}
/*
* 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;
}
/*
* Factorization helper for the command state machine:
* Submit a REQUEST SENSE and go to SENSE state.
*/
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) {
rc = -EPIPE;
goto error;
}
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->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;
scmd->back = cmd;
scmd->tag = sc->tagcnt++;
cmd->state = UB_CMDST_SENSE;
ub_cmdq_insert(sc, scmd);
return;
error:
ub_state_done(sc, cmd, rc);
}
/*
* A helper for the command's state machine:
* Submit a stall clear.
*/
static int ub_submit_clear_stall(struct ub_dev *sc, struct ub_scsi_cmd *cmd,
int stalled_pipe)
{
int endp;
struct usb_ctrlrequest *cr;
int rc;
endp = usb_pipeendpoint(stalled_pipe);
if (usb_pipein (stalled_pipe))
endp |= USB_DIR_IN;
cr = &sc->work_cr;
cr->bRequestType = USB_RECIP_ENDPOINT;
cr->bRequest = USB_REQ_CLEAR_FEATURE;
cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
cr->wIndex = cpu_to_le16(endp);
cr->wLength = cpu_to_le16(0);
UB_INIT_COMPLETION(sc->work_done);
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.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) {
ub_complete(&sc->work_done);
return rc;
}
sc->work_timer.expires = jiffies + UB_CTRL_TIMEOUT;
add_timer(&sc->work_timer);
return 0;
}
/*
*/
static void ub_top_sense_done(struct ub_dev *sc, struct ub_scsi_cmd *scmd)
{
unsigned char *sense = sc->top_sense;
struct ub_scsi_cmd *cmd;
/*
* Find the command which triggered the unit attention or a check,
* save the sense into it, and advance its state machine.
*/
if ((cmd = ub_cmdq_peek(sc)) == NULL) {
printk(KERN_WARNING "%s: sense done while idle\n", sc->name);
return;
}
if (cmd != scmd->back) {
printk(KERN_WARNING "%s: "
"sense done for wrong command 0x%x\n",
sc->name, cmd->tag);
return;
}
if (cmd->state != UB_CMDST_SENSE) {
printk(KERN_WARNING "%s: "
"sense done with bad cmd state %d\n",
sc->name, cmd->state);
return;
}
/*
* Ignoring scmd->act_len, because the buffer was pre-zeroed.
*/
cmd->key = sense[2] & 0x0F;
cmd->asc = sense[12];
cmd->ascq = sense[13];
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(struct work_struct *work)
{
struct ub_dev *sc = container_of(work, struct ub_dev, reset_work);
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)) {
;
} 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) {
;
} 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.
*/
static void ub_revalidate(struct ub_dev *sc, struct ub_lun *lun)
{
lun->readonly = 0; /* XXX Query this from the device */
lun->capacity.nsec = 0;
lun->capacity.bsize = 512;
lun->capacity.bshift = 0;
if (ub_sync_tur(sc, lun) != 0)
return; /* Not ready */
lun->changed = 0;
if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
/*
* The retry here means something is wrong, either with the
* device, with the transport, or with our code.
* We keep this because sd.c has retries for capacity.
*/
if (ub_sync_read_cap(sc, lun, &lun->capacity) != 0) {
lun->capacity.nsec = 0;
lun->capacity.bsize = 512;
lun->capacity.bshift = 0;
}
}
}
/*
* The open funcion.
* This is mostly needed to keep refcounting, but also to support
* media checks on removable media drives.
*/
static int ub_bd_open(struct inode *inode, struct file *filp)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
struct ub_lun *lun = disk->private_data;
struct ub_dev *sc = lun->udev;
unsigned long flags;
int rc;
spin_lock_irqsave(&ub_lock, flags);
if (atomic_read(&sc->poison)) {
spin_unlock_irqrestore(&ub_lock, flags);
return -ENXIO;
}
sc->openc++;
spin_unlock_irqrestore(&ub_lock, flags);
if (lun->removable || lun->readonly)
check_disk_change(inode->i_bdev);
/*
* The sd.c considers ->media_present and ->changed not equivalent,
* under some pretty murky conditions (a failure of READ CAPACITY).
* We may need it one day.
*/
if (lun->removable && lun->changed && !(filp->f_flags & O_NDELAY)) {
rc = -ENOMEDIUM;
goto err_open;
}
if (lun->readonly && (filp->f_mode & FMODE_WRITE)) {
rc = -EROFS;
goto err_open;
}
return 0;
err_open:
ub_put(sc);
return rc;
}
/*
*/
static int ub_bd_release(struct inode *inode, struct file *filp)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
struct ub_lun *lun = disk->private_data;
struct ub_dev *sc = lun->udev;
ub_put(sc);
return 0;
}
/*
* The ioctl interface.
*/
static int ub_bd_ioctl(struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
struct gendisk *disk = inode->i_bdev->bd_disk;
void __user *usermem = (void __user *) arg;
return scsi_cmd_ioctl(filp, disk, cmd, usermem);
}
/*
* This is called once a new disk was seen by the block layer or by ub_probe().
* The main onjective here is to discover the features of the media such as
* the capacity, read-only status, etc. USB storage generally does not
* need to be spun up, but if we needed it, this would be the place.
*
* This call can sleep.
*
* The return code is not used.
*/
static int ub_bd_revalidate(struct gendisk *disk)
{
struct ub_lun *lun = disk->private_data;
ub_revalidate(lun->udev, lun);
/* XXX Support sector size switching like in sr.c */
blk_queue_hardsect_size(disk->queue, lun->capacity.bsize);
set_capacity(disk, lun->capacity.nsec);
// set_disk_ro(sdkp->disk, lun->readonly);
return 0;
}
/*
* The check is called by the block layer to verify if the media
* is still available. It is supposed to be harmless, lightweight and
* non-intrusive in case the media was not changed.
*
* This call can sleep.
*
* The return code is bool!
*/
static int ub_bd_media_changed(struct gendisk *disk)
{
struct ub_lun *lun = disk->private_data;
if (!lun->removable)
return 0;
/*
* We clean checks always after every command, so this is not
* as dangerous as it looks. If the TEST_UNIT_READY fails here,
* the device is actually not ready with operator or software
* intervention required. One dangerous item might be a drive which
* spins itself down, and come the time to write dirty pages, this
* will fail, then block layer discards the data. Since we never
* spin drives up, such devices simply cannot be used with ub anyway.
*/
if (ub_sync_tur(lun->udev, lun) != 0) {
lun->changed = 1;
return 1;
}
return lun->changed;
}
static struct block_device_operations ub_bd_fops = {
.owner = THIS_MODULE,
.open = ub_bd_open,
.release = ub_bd_release,
.ioctl = ub_bd_ioctl,
.media_changed = ub_bd_media_changed,
.revalidate_disk = ub_bd_revalidate,
};
/*
* Common ->done routine for commands executed synchronously.
*/
static void ub_probe_done(struct ub_dev *sc, struct ub_scsi_cmd *cmd)
{
struct completion *cop = cmd->back;
complete(cop);
}
/*
* Test if the device has a check condition on it, synchronously.
*/
static int ub_sync_tur(struct ub_dev *sc, struct ub_lun *lun)
{
struct ub_scsi_cmd *cmd;
enum { ALLOC_SIZE = sizeof(struct ub_scsi_cmd) };
unsigned long flags;
struct completion compl;
int rc;
init_completion(&compl);
rc = -ENOMEM;
if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
goto err_alloc;
cmd->cdb[0] = TEST_UNIT_READY;
cmd->cdb_len = 6;
cmd->dir = UB_DIR_NONE;
cmd->state = UB_CMDST_INIT;
cmd->lun = lun; /* This may be NULL, but that's ok */
cmd->done = ub_probe_done;
cmd->back = &compl;
spin_lock_irqsave(sc->lock, flags);
cmd->tag = sc->tagcnt++;
rc = ub_submit_scsi(sc, cmd);
spin_unlock_irqrestore(sc->lock, flags);
if (rc != 0)
goto err_submit;
wait_for_completion(&compl);
rc = cmd->error;
if (rc == -EIO && cmd->key != 0) /* Retries for benh's key */
rc = cmd->key;
err_submit:
kfree(cmd);
err_alloc:
return rc;
}
/*
* Read the SCSI capacity synchronously (for probing).
*/
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;
unsigned int bsize, shift;
unsigned long nsec;
struct completion compl;
int rc;
init_completion(&compl);
rc = -ENOMEM;
if ((cmd = kzalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
goto err_alloc;
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->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);
cmd->tag = sc->tagcnt++;
rc = ub_submit_scsi(sc, cmd);
spin_unlock_irqrestore(sc->lock, flags);
if (rc != 0)
goto err_submit;
wait_for_completion(&compl);
if (cmd->error != 0) {
rc = -EIO;
goto err_read;
}
if (cmd->act_len != 8) {
rc = -EIO;
goto err_read;
}
/* sd.c special-cases sector size of 0 to mean 512. Needed? Safe? */
nsec = be32_to_cpu(*(__be32 *)p) + 1;
bsize = be32_to_cpu(*(__be32 *)(p + 4));
switch (bsize) {
case 512: shift = 0; break;
case 1024: shift = 1; break;
case 2048: shift = 2; break;
case 4096: shift = 3; break;
default:
rc = -EDOM;
goto err_inv_bsize;
}
ret->bsize = bsize;
ret->bshift = shift;
ret->nsec = nsec << shift;
rc = 0;
err_inv_bsize:
err_read:
err_submit:
kfree(cmd);
err_alloc:
return rc;
}
/*
*/
static void ub_probe_urb_complete(struct urb *urb)
{
struct completion *cop = urb->context;
complete(cop);
}
static void ub_probe_timeout(unsigned long arg)
{
struct completion *cop = (struct completion *) 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.
*/
static int ub_sync_getmaxlun(struct ub_dev *sc)
{
int ifnum = sc->intf->cur_altsetting->desc.bInterfaceNumber;
unsigned char *p;
enum { ALLOC_SIZE = 1 };
struct usb_ctrlrequest *cr;
struct completion compl;
struct timer_list timer;
int nluns;
int rc;
init_completion(&compl);
rc = -ENOMEM;
if ((p = kmalloc(ALLOC_SIZE, GFP_KERNEL)) == NULL)
goto err_alloc;
*p = 55;
cr = &sc->work_cr;
cr->bRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE;
cr->bRequest = US_BULK_GET_MAX_LUN;
cr->wValue = cpu_to_le16(0);
cr->wIndex = cpu_to_le16(ifnum);
cr->wLength = cpu_to_le16(1);
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.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)
goto err_submit;
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);
if ((rc = sc->work_urb.status) < 0)
goto err_io;
if (sc->work_urb.actual_length != 1) {
nluns = 0;
} else {
if ((nluns = *p) == 55) {
nluns = 0;
} else {
/* GetMaxLUN returns the maximum LUN number */
nluns += 1;
if (nluns > UB_MAX_LUNS)
nluns = UB_MAX_LUNS;
}
}
kfree(p);
return nluns;
err_io:
err_submit:
kfree(p);
err_alloc:
return rc;
}
/*
* Clear initial stalls.
*/
static int ub_probe_clear_stall(struct ub_dev *sc, int stalled_pipe)
{
int endp;
struct usb_ctrlrequest *cr;
struct completion compl;
struct timer_list timer;
int rc;
init_completion(&compl);
endp = usb_pipeendpoint(stalled_pipe);
if (usb_pipein (stalled_pipe))
endp |= USB_DIR_IN;
cr = &sc->work_cr;
cr->bRequestType = USB_RECIP_ENDPOINT;
cr->bRequest = USB_REQ_CLEAR_FEATURE;
cr->wValue = cpu_to_le16(USB_ENDPOINT_HALT);
cr->wIndex = cpu_to_le16(endp);
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 probe clear (%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);
/* reset the endpoint toggle */
usb_settoggle(sc->dev, endp, usb_pipeout(sc->last_pipe), 0);
return 0;
}
/*
* Get the pipe settings.
*/
static int ub_get_pipes(struct ub_dev *sc, struct usb_device *dev,
struct usb_interface *intf)
{
struct usb_host_interface *altsetting = intf->cur_altsetting;
struct usb_endpoint_descriptor *ep_in = NULL;
struct usb_endpoint_descriptor *ep_out = NULL;
struct usb_endpoint_descriptor *ep;
int i;
/*
* Find the endpoints we need.
* We are expecting a minimum of 2 endpoints - in and out (bulk).
* We will ignore any others.
*/
for (i = 0; i < altsetting->desc.bNumEndpoints; i++) {
ep = &altsetting->endpoint[i].desc;
/* Is it a BULK endpoint? */
if ((ep->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK)
== USB_ENDPOINT_XFER_BULK) {
/* BULK in or out? */
if (ep->bEndpointAddress & USB_DIR_IN) {
if (ep_in == NULL)
ep_in = ep;
} else {
if (ep_out == NULL)
ep_out = ep;
}
}
}
if (ep_in == NULL || ep_out == NULL) {
printk(KERN_NOTICE "%s: failed endpoint check\n",
sc->name);
return -ENODEV;
}
/* Calculate and store the pipe values */
sc->send_ctrl_pipe = usb_sndctrlpipe(dev, 0);
sc->recv_ctrl_pipe = usb_rcvctrlpipe(dev, 0);
sc->send_bulk_pipe = usb_sndbulkpipe(dev,
ep_out->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
sc->recv_bulk_pipe = usb_rcvbulkpipe(dev,
ep_in->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
return 0;
}
/*
* Probing is done in the process context, which allows us to cheat
* and not to build a state machine for the discovery.
*/
static int ub_probe(struct usb_interface *intf,
const struct usb_device_id *dev_id)
{
struct ub_dev *sc;
int nluns;
int rc;
int i;
if (usb_usual_check_type(dev_id, USB_US_TYPE_UB))
return -ENXIO;
rc = -ENOMEM;
if ((sc = kzalloc(sizeof(struct ub_dev), GFP_KERNEL)) == NULL)
goto err_core;
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);
init_waitqueue_head(&sc->reset_wait);
init_timer(&sc->work_timer);
sc->work_timer.data = (unsigned long) sc;
sc->work_timer.function = ub_urb_timeout;
ub_init_completion(&sc->work_done);
sc->work_done.done = 1; /* A little yuk, but oh well... */
sc->dev = interface_to_usbdev(intf);
sc->intf = intf;
// sc->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
usb_set_intfdata(intf, sc);
usb_get_dev(sc->dev);
/*
* 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) */
if (ub_get_pipes(sc, sc->dev, intf) != 0)
goto err_dev_desc;
/*
* At this point, all USB initialization is done, do upper layer.
* We really hate halfway initialized structures, so from the
* invariants perspective, this ub_dev is fully constructed at
* this point.
*/
/*
* 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.
* A SCSI check causes a USB stall. Our common case code sees it
* and clears the check, after which the device is ready for use.
* But if a check was not present, any command other than
* TEST_UNIT_READY ends with a lockup (including REQUEST_SENSE).
*
* If we neglect to clear the SCSI check, the first real command fails
* (which is the capacity readout). We clear that and retry, but why
* causing spurious retries for no reason.
*
* Revalidation may start with its own TEST_UNIT_READY, but that one
* has to succeed, so we clear checks with an additional one here.
* In any case it's not our business how revaliadation is implemented.
*/
for (i = 0; i < 3; i++) { /* Retries for the schwag key from KS'04 */
if ((rc = ub_sync_tur(sc, NULL)) <= 0) break;
if (rc != 0x6) break;
msleep(10);
}
nluns = 1;
for (i = 0; i < 3; i++) {
if ((rc = ub_sync_getmaxlun(sc)) < 0)
break;
if (rc != 0) {
nluns = rc;
break;
}
msleep(100);
}
for (i = 0; i < nluns; i++) {
ub_probe_lun(sc, i);
}
return 0;
err_dev_desc:
usb_set_intfdata(intf, NULL);
usb_put_intf(sc->intf);
usb_put_dev(sc->dev);
kfree(sc);
err_core:
return rc;
}
static int ub_probe_lun(struct ub_dev *sc, int lnum)
{
struct ub_lun *lun;
request_queue_t *q;
struct gendisk *disk;
int rc;
rc = -ENOMEM;
if ((lun = kzalloc(sizeof(struct ub_lun), GFP_KERNEL)) == NULL)
goto err_alloc;
lun->num = lnum;
rc = -ENOSR;
if ((lun->id = ub_id_get()) == -1)
goto err_id;
lun->udev = sc;
snprintf(lun->name, 16, DRV_NAME "%c(%d.%d.%d)",
lun->id + 'a', sc->dev->bus->busnum, sc->dev->devnum, lun->num);
lun->removable = 1; /* XXX Query this from the device */
lun->changed = 1; /* ub_revalidate clears only */
ub_revalidate(sc, lun);
rc = -ENOMEM;
if ((disk = alloc_disk(UB_PARTS_PER_LUN)) == NULL)
goto err_diskalloc;
sprintf(disk->disk_name, DRV_NAME "%c", lun->id + 'a');
disk->major = UB_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;
rc = -ENOMEM;
if ((q = blk_init_queue(ub_request_fn, sc->lock)) == NULL)
goto err_blkqinit;
disk->queue = q;
blk_queue_bounce_limit(q, BLK_BOUNCE_HIGH);
blk_queue_max_hw_segments(q, UB_MAX_REQ_SG);
blk_queue_max_phys_segments(q, UB_MAX_REQ_SG);
blk_queue_segment_boundary(q, 0xffffffff); /* Dubious. */
blk_queue_max_sectors(q, UB_MAX_SECTORS);
blk_queue_hardsect_size(q, lun->capacity.bsize);
lun->disk = disk;
q->queuedata = lun;
list_add(&lun->link, &sc->luns);
set_capacity(disk, lun->capacity.nsec);
if (lun->removable)
disk->flags |= GENHD_FL_REMOVABLE;
add_disk(disk);
return 0;
err_blkqinit:
put_disk(disk);
err_diskalloc:
ub_id_put(lun->id);
err_id:
kfree(lun);
err_alloc:
return rc;
}
static void ub_disconnect(struct usb_interface *intf)
{
struct ub_dev *sc = usb_get_intfdata(intf);
struct list_head *p;
struct ub_lun *lun;
unsigned long flags;
/*
* Prevent ub_bd_release from pulling the rug from under us.
* XXX This is starting to look like a kref.
* XXX Why not to take this ref at probe time?
*/
spin_lock_irqsave(&ub_lock, flags);
sc->openc++;
spin_unlock_irqrestore(&ub_lock, flags);
/*
* Fence stall clearnings, operations triggered by unlinkings and so on.
* We do not attempt to unlink any URBs, because we do not trust the
* unlink paths in HC drivers. Also, we get -84 upon disconnect anyway.
*/
atomic_set(&sc->poison, 1);
/*
* Wait for reset to end, if any.
*/
wait_event(sc->reset_wait, !sc->reset);
/*
* Blow away queued commands.
*
* Actually, this never works, because before we get here
* the HCD terminates outstanding URB(s). It causes our
* SCSI command queue to advance, commands fail to submit,
* and the whole queue drains. So, we just use this code to
* print warnings.
*/
spin_lock_irqsave(sc->lock, flags);
{
struct ub_scsi_cmd *cmd;
int cnt = 0;
while ((cmd = ub_cmdq_peek(sc)) != NULL) {
cmd->error = -ENOTCONN;
cmd->state = UB_CMDST_DONE;
ub_cmdq_pop(sc);
(*cmd->done)(sc, cmd);
cnt++;
}
if (cnt != 0) {
printk(KERN_WARNING "%s: "
"%d was queued after shutdown\n", sc->name, cnt);
}
}
spin_unlock_irqrestore(sc->lock, flags);
/*
* Unregister the upper layer.
*/
list_for_each (p, &sc->luns) {
lun = list_entry(p, struct ub_lun, link);
del_gendisk(lun->disk);
/*
* I wish I could do:
* set_bit(QUEUE_FLAG_DEAD, &q->queue_flags);
* As it is, we rely on our internal poisoning and let
* the upper levels to spin furiously failing all the I/O.
*/
}
/*
* Testing for -EINPROGRESS is always a bug, so we are bending
* the rules a little.
*/
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);
/*
* There is virtually no chance that other CPU runs times so long
* after ub_urb_complete should have called del_timer, but only if HCD
* didn't forget to deliver a callback on unlink.
*/
del_timer_sync(&sc->work_timer);
/*
* At this point there must be no commands coming from anyone
* and no URBs left in transit.
*/
ub_put(sc);
}
static struct usb_driver ub_driver = {
.name = "ub",
.probe = ub_probe,
.disconnect = ub_disconnect,
.id_table = ub_usb_ids,
};
static int __init ub_init(void)
{
int rc;
int i;
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;
if ((rc = usb_register(&ub_driver)) != 0)
goto err_register;
usb_usual_set_present(USB_US_TYPE_UB);
return 0;
err_register:
unregister_blkdev(UB_MAJOR, DRV_NAME);
err_regblkdev:
return rc;
}
static void __exit ub_exit(void)
{
usb_deregister(&ub_driver);
unregister_blkdev(UB_MAJOR, DRV_NAME);
usb_usual_clear_present(USB_US_TYPE_UB);
}
module_init(ub_init);
module_exit(ub_exit);
MODULE_LICENSE("GPL");
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