alistair23-linux/drivers/usb/storage/usb.h
Alan Stern 2f67cd5b1d usb-storage: fix bugs in the disconnect pathway
This patch (as961) fixes a couple of bugs in the disconnect pathway of
usb-storage.

The first problem, which apparently has been around for a while
although nobody noticed it, shows up when an aborted command is still
pending when a disconnect occurs.  The SCSI error-handler will
continue to wait in command_abort() until the us->notify completion is
signalled.  Thus quiesce_and_remove_host() needs to signal it.

The second problem was introduced recently along with autosuspend
support.  Since usb_stor_scan_thread() now calls
usb_autopm_put_interface() before exiting, we can't simply leave the
scanning thread running after a disconnect; we must wait until the
thread exits.  This is solved by adding a new struct completion to the
private data structure.  Fortuitously, it allows the removal of the
rather clunky mechanism used in the past to insure that all threads
have finished before the module is unloaded.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2007-08-22 14:27:52 -07:00

181 lines
6.4 KiB
C

/* Driver for USB Mass Storage compliant devices
* Main Header File
*
* $Id: usb.h,v 1.21 2002/04/21 02:57:59 mdharm Exp $
*
* Current development and maintenance by:
* (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
*
* Initial work by:
* (c) 1999 Michael Gee (michael@linuxspecific.com)
*
* This driver is based on the 'USB Mass Storage Class' document. This
* describes in detail the protocol used to communicate with such
* devices. Clearly, the designers had SCSI and ATAPI commands in
* mind when they created this document. The commands are all very
* similar to commands in the SCSI-II and ATAPI specifications.
*
* It is important to note that in a number of cases this class
* exhibits class-specific exemptions from the USB specification.
* Notably the usage of NAK, STALL and ACK differs from the norm, in
* that they are used to communicate wait, failed and OK on commands.
*
* Also, for certain devices, the interrupt endpoint is used to convey
* status of a command.
*
* Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
* information about this driver.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef _USB_H_
#define _USB_H_
#include <linux/usb.h>
#include <linux/usb_usual.h>
#include <linux/blkdev.h>
#include <linux/completion.h>
#include <linux/mutex.h>
#include <scsi/scsi_host.h>
struct us_data;
struct scsi_cmnd;
/*
* Unusual device list definitions
*/
struct us_unusual_dev {
const char* vendorName;
const char* productName;
__u8 useProtocol;
__u8 useTransport;
int (*initFunction)(struct us_data *);
};
/* Dynamic flag definitions: used in set_bit() etc. */
#define US_FLIDX_URB_ACTIVE 18 /* 0x00040000 current_urb is in use */
#define US_FLIDX_SG_ACTIVE 19 /* 0x00080000 current_sg is in use */
#define US_FLIDX_ABORTING 20 /* 0x00100000 abort is in progress */
#define US_FLIDX_DISCONNECTING 21 /* 0x00200000 disconnect in progress */
#define ABORTING_OR_DISCONNECTING ((1UL << US_FLIDX_ABORTING) | \
(1UL << US_FLIDX_DISCONNECTING))
#define US_FLIDX_RESETTING 22 /* 0x00400000 device reset in progress */
#define US_FLIDX_TIMED_OUT 23 /* 0x00800000 SCSI midlayer timed out */
#define USB_STOR_STRING_LEN 32
/*
* We provide a DMA-mapped I/O buffer for use with small USB transfers.
* It turns out that CB[I] needs a 12-byte buffer and Bulk-only needs a
* 31-byte buffer. But Freecom needs a 64-byte buffer, so that's the
* size we'll allocate.
*/
#define US_IOBUF_SIZE 64 /* Size of the DMA-mapped I/O buffer */
#define US_SENSE_SIZE 18 /* Size of the autosense data buffer */
typedef int (*trans_cmnd)(struct scsi_cmnd *, struct us_data*);
typedef int (*trans_reset)(struct us_data*);
typedef void (*proto_cmnd)(struct scsi_cmnd*, struct us_data*);
typedef void (*extra_data_destructor)(void *); /* extra data destructor */
typedef void (*pm_hook)(struct us_data *, int); /* power management hook */
#define US_SUSPEND 0
#define US_RESUME 1
/* we allocate one of these for every device that we remember */
struct us_data {
/* The device we're working with
* It's important to note:
* (o) you must hold dev_mutex to change pusb_dev
*/
struct mutex dev_mutex; /* protect pusb_dev */
struct usb_device *pusb_dev; /* this usb_device */
struct usb_interface *pusb_intf; /* this interface */
struct us_unusual_dev *unusual_dev; /* device-filter entry */
unsigned long flags; /* from filter initially */
unsigned int send_bulk_pipe; /* cached pipe values */
unsigned int recv_bulk_pipe;
unsigned int send_ctrl_pipe;
unsigned int recv_ctrl_pipe;
unsigned int recv_intr_pipe;
/* information about the device */
char *transport_name;
char *protocol_name;
__le32 bcs_signature;
u8 subclass;
u8 protocol;
u8 max_lun;
u8 ifnum; /* interface number */
u8 ep_bInterval; /* interrupt interval */
/* function pointers for this device */
trans_cmnd transport; /* transport function */
trans_reset transport_reset; /* transport device reset */
proto_cmnd proto_handler; /* protocol handler */
/* SCSI interfaces */
struct scsi_cmnd *srb; /* current srb */
unsigned int tag; /* current dCBWTag */
/* control and bulk communications data */
struct urb *current_urb; /* USB requests */
struct usb_ctrlrequest *cr; /* control requests */
struct usb_sg_request current_sg; /* scatter-gather req. */
unsigned char *iobuf; /* I/O buffer */
unsigned char *sensebuf; /* sense data buffer */
dma_addr_t cr_dma; /* buffer DMA addresses */
dma_addr_t iobuf_dma;
struct task_struct *ctl_thread; /* the control thread */
/* mutual exclusion and synchronization structures */
struct semaphore sema; /* to sleep thread on */
struct completion notify; /* thread begin/end */
wait_queue_head_t delay_wait; /* wait during scan, reset */
struct completion scanning_done; /* wait for scan thread */
/* subdriver information */
void *extra; /* Any extra data */
extra_data_destructor extra_destructor;/* extra data destructor */
#ifdef CONFIG_PM
pm_hook suspend_resume_hook;
#endif
};
/* Convert between us_data and the corresponding Scsi_Host */
static inline struct Scsi_Host *us_to_host(struct us_data *us) {
return container_of((void *) us, struct Scsi_Host, hostdata);
}
static inline struct us_data *host_to_us(struct Scsi_Host *host) {
return (struct us_data *) host->hostdata;
}
/* Function to fill an inquiry response. See usb.c for details */
extern void fill_inquiry_response(struct us_data *us,
unsigned char *data, unsigned int data_len);
/* The scsi_lock() and scsi_unlock() macros protect the sm_state and the
* single queue element srb for write access */
#define scsi_unlock(host) spin_unlock_irq(host->host_lock)
#define scsi_lock(host) spin_lock_irq(host->host_lock)
#endif