Initial import

1 files changed, 1385 insertions, 0 deletions

diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
new file mode 100644
index 000000000..540add24a
--- /dev/null
+++ b/drivers/usb/storage/transport.c
@@ -0,0 +1,1385 @@
+/* Driver for USB Mass Storage compliant devices
+ *
+ * Current development and maintenance by:
+ *   (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
+ *
+ * Developed with the assistance of:
+ *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
+ *   (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
+ *   (c) 2002 Alan Stern <stern@rowland.org>
+ *
+ * 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.
+ */
+
+#include <linux/sched.h>
+#include <linux/gfp.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+
+#include <linux/usb/quirks.h>
+
+#include <scsi/scsi.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_device.h>
+
+#include "usb.h"
+#include "transport.h"
+#include "protocol.h"
+#include "scsiglue.h"
+#include "debug.h"
+
+#include <linux/blkdev.h>
+#include "../../scsi/sd.h"
+
+
+/***********************************************************************
+ * Data transfer routines
+ ***********************************************************************/
+
+/*
+ * This is subtle, so pay attention:
+ * ---------------------------------
+ * We're very concerned about races with a command abort.  Hanging this code
+ * is a sure fire way to hang the kernel.  (Note that this discussion applies
+ * only to transactions resulting from a scsi queued-command, since only
+ * these transactions are subject to a scsi abort.  Other transactions, such
+ * as those occurring during device-specific initialization, must be handled
+ * by a separate code path.)
+ *
+ * The abort function (usb_storage_command_abort() in scsiglue.c) first
+ * sets the machine state and the ABORTING bit in us->dflags to prevent
+ * new URBs from being submitted.  It then calls usb_stor_stop_transport()
+ * below, which atomically tests-and-clears the URB_ACTIVE bit in us->dflags
+ * to see if the current_urb needs to be stopped.  Likewise, the SG_ACTIVE
+ * bit is tested to see if the current_sg scatter-gather request needs to be
+ * stopped.  The timeout callback routine does much the same thing.
+ *
+ * When a disconnect occurs, the DISCONNECTING bit in us->dflags is set to
+ * prevent new URBs from being submitted, and usb_stor_stop_transport() is
+ * called to stop any ongoing requests.
+ *
+ * The submit function first verifies that the submitting is allowed
+ * (neither ABORTING nor DISCONNECTING bits are set) and that the submit
+ * completes without errors, and only then sets the URB_ACTIVE bit.  This
+ * prevents the stop_transport() function from trying to cancel the URB
+ * while the submit call is underway.  Next, the submit function must test
+ * the flags to see if an abort or disconnect occurred during the submission
+ * or before the URB_ACTIVE bit was set.  If so, it's essential to cancel
+ * the URB if it hasn't been cancelled already (i.e., if the URB_ACTIVE bit
+ * is still set).  Either way, the function must then wait for the URB to
+ * finish.  Note that the URB can still be in progress even after a call to
+ * usb_unlink_urb() returns.
+ *
+ * The idea is that (1) once the ABORTING or DISCONNECTING bit is set,
+ * either the stop_transport() function or the submitting function
+ * is guaranteed to call usb_unlink_urb() for an active URB,
+ * and (2) test_and_clear_bit() prevents usb_unlink_urb() from being
+ * called more than once or from being called during usb_submit_urb().
+ */
+
+/* This is the completion handler which will wake us up when an URB
+ * completes.
+ */
+static void usb_stor_blocking_completion(struct urb *urb)
+{
+	struct completion *urb_done_ptr = urb->context;
+
+	complete(urb_done_ptr);
+}
+
+/* This is the common part of the URB message submission code
+ *
+ * All URBs from the usb-storage driver involved in handling a queued scsi
+ * command _must_ pass through this function (or something like it) for the
+ * abort mechanisms to work properly.
+ */
+static int usb_stor_msg_common(struct us_data *us, int timeout)
+{
+	struct completion urb_done;
+	long timeleft;
+	int status;
+
+	/* don't submit URBs during abort processing */
+	if (test_bit(US_FLIDX_ABORTING, &us->dflags))
+		return -EIO;
+
+	/* set up data structures for the wakeup system */
+	init_completion(&urb_done);
+
+	/* fill the common fields in the URB */
+	us->current_urb->context = &urb_done;
+	us->current_urb->transfer_flags = 0;
+
+	/* we assume that if transfer_buffer isn't us->iobuf then it
+	 * hasn't been mapped for DMA.  Yes, this is clunky, but it's
+	 * easier than always having the caller tell us whether the
+	 * transfer buffer has already been mapped. */
+	if (us->current_urb->transfer_buffer == us->iobuf)
+		us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	us->current_urb->transfer_dma = us->iobuf_dma;
+
+	/* submit the URB */
+	status = usb_submit_urb(us->current_urb, GFP_NOIO);
+	if (status) {
+		/* something went wrong */
+		return status;
+	}
+
+	/* since the URB has been submitted successfully, it's now okay
+	 * to cancel it */
+	set_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
+
+	/* did an abort occur during the submission? */
+	if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
+
+		/* cancel the URB, if it hasn't been cancelled already */
+		if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
+			usb_stor_dbg(us, "-- cancelling URB\n");
+			usb_unlink_urb(us->current_urb);
+		}
+	}
+ 
+	/* wait for the completion of the URB */
+	timeleft = wait_for_completion_interruptible_timeout(
+			&urb_done, timeout ? : MAX_SCHEDULE_TIMEOUT);
+ 
+	clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
+
+	if (timeleft <= 0) {
+		usb_stor_dbg(us, "%s -- cancelling URB\n",
+			     timeleft == 0 ? "Timeout" : "Signal");
+		usb_kill_urb(us->current_urb);
+	}
+
+	/* return the URB status */
+	return us->current_urb->status;
+}
+
+/*
+ * Transfer one control message, with timeouts, and allowing early
+ * termination.  Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx.
+ */
+int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
+		 u8 request, u8 requesttype, u16 value, u16 index, 
+		 void *data, u16 size, int timeout)
+{
+	int status;
+
+	usb_stor_dbg(us, "rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
+		     request, requesttype, value, index, size);
+
+	/* fill in the devrequest structure */
+	us->cr->bRequestType = requesttype;
+	us->cr->bRequest = request;
+	us->cr->wValue = cpu_to_le16(value);
+	us->cr->wIndex = cpu_to_le16(index);
+	us->cr->wLength = cpu_to_le16(size);
+
+	/* fill and submit the URB */
+	usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe, 
+			 (unsigned char*) us->cr, data, size, 
+			 usb_stor_blocking_completion, NULL);
+	status = usb_stor_msg_common(us, timeout);
+
+	/* return the actual length of the data transferred if no error */
+	if (status == 0)
+		status = us->current_urb->actual_length;
+	return status;
+}
+EXPORT_SYMBOL_GPL(usb_stor_control_msg);
+
+/* This is a version of usb_clear_halt() that allows early termination and
+ * doesn't read the status from the device -- this is because some devices
+ * crash their internal firmware when the status is requested after a halt.
+ *
+ * A definitive list of these 'bad' devices is too difficult to maintain or
+ * make complete enough to be useful.  This problem was first observed on the
+ * Hagiwara FlashGate DUAL unit.  However, bus traces reveal that neither
+ * MacOS nor Windows checks the status after clearing a halt.
+ *
+ * Since many vendors in this space limit their testing to interoperability
+ * with these two OSes, specification violations like this one are common.
+ */
+int usb_stor_clear_halt(struct us_data *us, unsigned int pipe)
+{
+	int result;
+	int endp = usb_pipeendpoint(pipe);
+
+	if (usb_pipein (pipe))
+		endp |= USB_DIR_IN;
+
+	result = usb_stor_control_msg(us, us->send_ctrl_pipe,
+		USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
+		USB_ENDPOINT_HALT, endp,
+		NULL, 0, 3*HZ);
+
+	if (result >= 0)
+		usb_reset_endpoint(us->pusb_dev, endp);
+
+	usb_stor_dbg(us, "result = %d\n", result);
+	return result;
+}
+EXPORT_SYMBOL_GPL(usb_stor_clear_halt);
+
+
+/*
+ * Interpret the results of a URB transfer
+ *
+ * This function prints appropriate debugging messages, clears halts on
+ * non-control endpoints, and translates the status to the corresponding
+ * USB_STOR_XFER_xxx return code.
+ */
+static int interpret_urb_result(struct us_data *us, unsigned int pipe,
+		unsigned int length, int result, unsigned int partial)
+{
+	usb_stor_dbg(us, "Status code %d; transferred %u/%u\n",
+		     result, partial, length);
+	switch (result) {
+
+	/* no error code; did we send all the data? */
+	case 0:
+		if (partial != length) {
+			usb_stor_dbg(us, "-- short transfer\n");
+			return USB_STOR_XFER_SHORT;
+		}
+
+		usb_stor_dbg(us, "-- transfer complete\n");
+		return USB_STOR_XFER_GOOD;
+
+	/* stalled */
+	case -EPIPE:
+		/* for control endpoints, (used by CB[I]) a stall indicates
+		 * a failed command */
+		if (usb_pipecontrol(pipe)) {
+			usb_stor_dbg(us, "-- stall on control pipe\n");
+			return USB_STOR_XFER_STALLED;
+		}
+
+		/* for other sorts of endpoint, clear the stall */
+		usb_stor_dbg(us, "clearing endpoint halt for pipe 0x%x\n",
+			     pipe);
+		if (usb_stor_clear_halt(us, pipe) < 0)
+			return USB_STOR_XFER_ERROR;
+		return USB_STOR_XFER_STALLED;
+
+	/* babble - the device tried to send more than we wanted to read */
+	case -EOVERFLOW:
+		usb_stor_dbg(us, "-- babble\n");
+		return USB_STOR_XFER_LONG;
+
+	/* the transfer was cancelled by abort, disconnect, or timeout */
+	case -ECONNRESET:
+		usb_stor_dbg(us, "-- transfer cancelled\n");
+		return USB_STOR_XFER_ERROR;
+
+	/* short scatter-gather read transfer */
+	case -EREMOTEIO:
+		usb_stor_dbg(us, "-- short read transfer\n");
+		return USB_STOR_XFER_SHORT;
+
+	/* abort or disconnect in progress */
+	case -EIO:
+		usb_stor_dbg(us, "-- abort or disconnect in progress\n");
+		return USB_STOR_XFER_ERROR;
+
+	/* the catch-all error case */
+	default:
+		usb_stor_dbg(us, "-- unknown error\n");
+		return USB_STOR_XFER_ERROR;
+	}
+}
+
+/*
+ * Transfer one control message, without timeouts, but allowing early
+ * termination.  Return codes are USB_STOR_XFER_xxx.
+ */
+int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
+		u8 request, u8 requesttype, u16 value, u16 index,
+		void *data, u16 size)
+{
+	int result;
+
+	usb_stor_dbg(us, "rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
+		     request, requesttype, value, index, size);
+
+	/* fill in the devrequest structure */
+	us->cr->bRequestType = requesttype;
+	us->cr->bRequest = request;
+	us->cr->wValue = cpu_to_le16(value);
+	us->cr->wIndex = cpu_to_le16(index);
+	us->cr->wLength = cpu_to_le16(size);
+
+	/* fill and submit the URB */
+	usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe, 
+			 (unsigned char*) us->cr, data, size, 
+			 usb_stor_blocking_completion, NULL);
+	result = usb_stor_msg_common(us, 0);
+
+	return interpret_urb_result(us, pipe, size, result,
+			us->current_urb->actual_length);
+}
+EXPORT_SYMBOL_GPL(usb_stor_ctrl_transfer);
+
+/*
+ * Receive one interrupt buffer, without timeouts, but allowing early
+ * termination.  Return codes are USB_STOR_XFER_xxx.
+ *
+ * This routine always uses us->recv_intr_pipe as the pipe and
+ * us->ep_bInterval as the interrupt interval.
+ */
+static int usb_stor_intr_transfer(struct us_data *us, void *buf,
+				  unsigned int length)
+{
+	int result;
+	unsigned int pipe = us->recv_intr_pipe;
+	unsigned int maxp;
+
+	usb_stor_dbg(us, "xfer %u bytes\n", length);
+
+	/* calculate the max packet size */
+	maxp = usb_maxpacket(us->pusb_dev, pipe, usb_pipeout(pipe));
+	if (maxp > length)
+		maxp = length;
+
+	/* fill and submit the URB */
+	usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf,
+			maxp, usb_stor_blocking_completion, NULL,
+			us->ep_bInterval);
+	result = usb_stor_msg_common(us, 0);
+
+	return interpret_urb_result(us, pipe, length, result,
+			us->current_urb->actual_length);
+}
+
+/*
+ * Transfer one buffer via bulk pipe, without timeouts, but allowing early
+ * termination.  Return codes are USB_STOR_XFER_xxx.  If the bulk pipe
+ * stalls during the transfer, the halt is automatically cleared.
+ */
+int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
+	void *buf, unsigned int length, unsigned int *act_len)
+{
+	int result;
+
+	usb_stor_dbg(us, "xfer %u bytes\n", length);
+
+	/* fill and submit the URB */
+	usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length,
+		      usb_stor_blocking_completion, NULL);
+	result = usb_stor_msg_common(us, 0);
+
+	/* store the actual length of the data transferred */
+	if (act_len)
+		*act_len = us->current_urb->actual_length;
+	return interpret_urb_result(us, pipe, length, result, 
+			us->current_urb->actual_length);
+}
+EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_buf);
+
+/*
+ * Transfer a scatter-gather list via bulk transfer
+ *
+ * This function does basically the same thing as usb_stor_bulk_transfer_buf()
+ * above, but it uses the usbcore scatter-gather library.
+ */
+static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
+		struct scatterlist *sg, int num_sg, unsigned int length,
+		unsigned int *act_len)
+{
+	int result;
+
+	/* don't submit s-g requests during abort processing */
+	if (test_bit(US_FLIDX_ABORTING, &us->dflags))
+		return USB_STOR_XFER_ERROR;
+
+	/* initialize the scatter-gather request block */
+	usb_stor_dbg(us, "xfer %u bytes, %d entries\n", length, num_sg);
+	result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
+			sg, num_sg, length, GFP_NOIO);
+	if (result) {
+		usb_stor_dbg(us, "usb_sg_init returned %d\n", result);
+		return USB_STOR_XFER_ERROR;
+	}
+
+	/* since the block has been initialized successfully, it's now
+	 * okay to cancel it */
+	set_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
+
+	/* did an abort occur during the submission? */
+	if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
+
+		/* cancel the request, if it hasn't been cancelled already */
+		if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
+			usb_stor_dbg(us, "-- cancelling sg request\n");
+			usb_sg_cancel(&us->current_sg);
+		}
+	}
+
+	/* wait for the completion of the transfer */
+	usb_sg_wait(&us->current_sg);
+	clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
+
+	result = us->current_sg.status;
+	if (act_len)
+		*act_len = us->current_sg.bytes;
+	return interpret_urb_result(us, pipe, length, result,
+			us->current_sg.bytes);
+}
+
+/*
+ * Common used function. Transfer a complete command
+ * via usb_stor_bulk_transfer_sglist() above. Set cmnd resid
+ */
+int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
+		      struct scsi_cmnd* srb)
+{
+	unsigned int partial;
+	int result = usb_stor_bulk_transfer_sglist(us, pipe, scsi_sglist(srb),
+				      scsi_sg_count(srb), scsi_bufflen(srb),
+				      &partial);
+
+	scsi_set_resid(srb, scsi_bufflen(srb) - partial);
+	return result;
+}
+EXPORT_SYMBOL_GPL(usb_stor_bulk_srb);
+
+/*
+ * Transfer an entire SCSI command's worth of data payload over the bulk
+ * pipe.
+ *
+ * Note that this uses usb_stor_bulk_transfer_buf() and
+ * usb_stor_bulk_transfer_sglist() to achieve its goals --
+ * this function simply determines whether we're going to use
+ * scatter-gather or not, and acts appropriately.
+ */
+int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe,
+		void *buf, unsigned int length_left, int use_sg, int *residual)
+{
+	int result;
+	unsigned int partial;
+
+	/* are we scatter-gathering? */
+	if (use_sg) {
+		/* use the usb core scatter-gather primitives */
+		result = usb_stor_bulk_transfer_sglist(us, pipe,
+				(struct scatterlist *) buf, use_sg,
+				length_left, &partial);
+		length_left -= partial;
+	} else {
+		/* no scatter-gather, just make the request */
+		result = usb_stor_bulk_transfer_buf(us, pipe, buf, 
+				length_left, &partial);
+		length_left -= partial;
+	}
+
+	/* store the residual and return the error code */
+	if (residual)
+		*residual = length_left;
+	return result;
+}
+EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_sg);
+
+/***********************************************************************
+ * Transport routines
+ ***********************************************************************/
+
+/* There are so many devices that report the capacity incorrectly,
+ * this routine was written to counteract some of the resulting
+ * problems.
+ */
+static void last_sector_hacks(struct us_data *us, struct scsi_cmnd *srb)
+{
+	struct gendisk *disk;
+	struct scsi_disk *sdkp;
+	u32 sector;
+
+	/* To Report "Medium Error: Record Not Found */
+	static unsigned char record_not_found[18] = {
+		[0]	= 0x70,			/* current error */
+		[2]	= MEDIUM_ERROR,		/* = 0x03 */
+		[7]	= 0x0a,			/* additional length */
+		[12]	= 0x14			/* Record Not Found */
+	};
+
+	/* If last-sector problems can't occur, whether because the
+	 * capacity was already decremented or because the device is
+	 * known to report the correct capacity, then we don't need
+	 * to do anything.
+	 */
+	if (!us->use_last_sector_hacks)
+		return;
+
+	/* Was this command a READ(10) or a WRITE(10)? */
+	if (srb->cmnd[0] != READ_10 && srb->cmnd[0] != WRITE_10)
+		goto done;
+
+	/* Did this command access the last sector? */
+	sector = (srb->cmnd[2] << 24) | (srb->cmnd[3] << 16) |
+			(srb->cmnd[4] << 8) | (srb->cmnd[5]);
+	disk = srb->request->rq_disk;
+	if (!disk)
+		goto done;
+	sdkp = scsi_disk(disk);
+	if (!sdkp)
+		goto done;
+	if (sector + 1 != sdkp->capacity)
+		goto done;
+
+	if (srb->result == SAM_STAT_GOOD && scsi_get_resid(srb) == 0) {
+
+		/* The command succeeded.  We know this device doesn't
+		 * have the last-sector bug, so stop checking it.
+		 */
+		us->use_last_sector_hacks = 0;
+
+	} else {
+		/* The command failed.  Allow up to 3 retries in case this
+		 * is some normal sort of failure.  After that, assume the
+		 * capacity is wrong and we're trying to access the sector
+		 * beyond the end.  Replace the result code and sense data
+		 * with values that will cause the SCSI core to fail the
+		 * command immediately, instead of going into an infinite
+		 * (or even just a very long) retry loop.
+		 */
+		if (++us->last_sector_retries < 3)
+			return;
+		srb->result = SAM_STAT_CHECK_CONDITION;
+		memcpy(srb->sense_buffer, record_not_found,
+				sizeof(record_not_found));
+	}
+
+ done:
+	/* Don't reset the retry counter for TEST UNIT READY commands,
+	 * because they get issued after device resets which might be
+	 * caused by a failed last-sector access.
+	 */
+	if (srb->cmnd[0] != TEST_UNIT_READY)
+		us->last_sector_retries = 0;
+}
+
+/* Invoke the transport and basic error-handling/recovery methods
+ *
+ * This is used by the protocol layers to actually send the message to
+ * the device and receive the response.
+ */
+void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
+{
+	int need_auto_sense;
+	int result;
+
+	/* send the command to the transport layer */
+	scsi_set_resid(srb, 0);
+	result = us->transport(srb, us);
+
+	/* if the command gets aborted by the higher layers, we need to
+	 * short-circuit all other processing
+	 */
+	if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
+		usb_stor_dbg(us, "-- command was aborted\n");
+		srb->result = DID_ABORT << 16;
+		goto Handle_Errors;
+	}
+
+	/* if there is a transport error, reset and don't auto-sense */
+	if (result == USB_STOR_TRANSPORT_ERROR) {
+		usb_stor_dbg(us, "-- transport indicates error, resetting\n");
+		srb->result = DID_ERROR << 16;
+		goto Handle_Errors;
+	}
+
+	/* if the transport provided its own sense data, don't auto-sense */
+	if (result == USB_STOR_TRANSPORT_NO_SENSE) {
+		srb->result = SAM_STAT_CHECK_CONDITION;
+		last_sector_hacks(us, srb);
+		return;
+	}
+
+	srb->result = SAM_STAT_GOOD;
+
+	/* Determine if we need to auto-sense
+	 *
+	 * I normally don't use a flag like this, but it's almost impossible
+	 * to understand what's going on here if I don't.
+	 */
+	need_auto_sense = 0;
+
+	/*
+	 * If we're running the CB transport, which is incapable
+	 * of determining status on its own, we will auto-sense
+	 * unless the operation involved a data-in transfer.  Devices
+	 * can signal most data-in errors by stalling the bulk-in pipe.
+	 */
+	if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_DPCM_USB) &&
+			srb->sc_data_direction != DMA_FROM_DEVICE) {
+		usb_stor_dbg(us, "-- CB transport device requiring auto-sense\n");
+		need_auto_sense = 1;
+	}
+
+	/*
+	 * If we have a failure, we're going to do a REQUEST_SENSE 
+	 * automatically.  Note that we differentiate between a command
+	 * "failure" and an "error" in the transport mechanism.
+	 */
+	if (result == USB_STOR_TRANSPORT_FAILED) {
+		usb_stor_dbg(us, "-- transport indicates command failure\n");
+		need_auto_sense = 1;
+	}
+
+	/*
+	 * Determine if this device is SAT by seeing if the
+	 * command executed successfully.  Otherwise we'll have
+	 * to wait for at least one CHECK_CONDITION to determine
+	 * SANE_SENSE support
+	 */
+	if (unlikely((srb->cmnd[0] == ATA_16 || srb->cmnd[0] == ATA_12) &&
+	    result == USB_STOR_TRANSPORT_GOOD &&
+	    !(us->fflags & US_FL_SANE_SENSE) &&
+	    !(us->fflags & US_FL_BAD_SENSE) &&
+	    !(srb->cmnd[2] & 0x20))) {
+		usb_stor_dbg(us, "-- SAT supported, increasing auto-sense\n");
+		us->fflags |= US_FL_SANE_SENSE;
+	}
+
+	/*
+	 * A short transfer on a command where we don't expect it
+	 * is unusual, but it doesn't mean we need to auto-sense.
+	 */
+	if ((scsi_get_resid(srb) > 0) &&
+	    !((srb->cmnd[0] == REQUEST_SENSE) ||
+	      (srb->cmnd[0] == INQUIRY) ||
+	      (srb->cmnd[0] == MODE_SENSE) ||
+	      (srb->cmnd[0] == LOG_SENSE) ||
+	      (srb->cmnd[0] == MODE_SENSE_10))) {
+		usb_stor_dbg(us, "-- unexpectedly short transfer\n");
+	}
+
+	/* Now, if we need to do the auto-sense, let's do it */
+	if (need_auto_sense) {
+		int temp_result;
+		struct scsi_eh_save ses;
+		int sense_size = US_SENSE_SIZE;
+		struct scsi_sense_hdr sshdr;
+		const u8 *scdd;
+		u8 fm_ili;
+
+		/* device supports and needs bigger sense buffer */
+		if (us->fflags & US_FL_SANE_SENSE)
+			sense_size = ~0;
+Retry_Sense:
+		usb_stor_dbg(us, "Issuing auto-REQUEST_SENSE\n");
+
+		scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sense_size);
+
+		/* FIXME: we must do the protocol translation here */
+		if (us->subclass == USB_SC_RBC || us->subclass == USB_SC_SCSI ||
+				us->subclass == USB_SC_CYP_ATACB)
+			srb->cmd_len = 6;
+		else
+			srb->cmd_len = 12;
+
+		/* issue the auto-sense command */
+		scsi_set_resid(srb, 0);
+		temp_result = us->transport(us->srb, us);
+
+		/* let's clean up right away */
+		scsi_eh_restore_cmnd(srb, &ses);
+
+		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
+			usb_stor_dbg(us, "-- auto-sense aborted\n");
+			srb->result = DID_ABORT << 16;
+
+			/* If SANE_SENSE caused this problem, disable it */
+			if (sense_size != US_SENSE_SIZE) {
+				us->fflags &= ~US_FL_SANE_SENSE;
+				us->fflags |= US_FL_BAD_SENSE;
+			}
+			goto Handle_Errors;
+		}
+
+		/* Some devices claim to support larger sense but fail when
+		 * trying to request it. When a transport failure happens
+		 * using US_FS_SANE_SENSE, we always retry with a standard
+		 * (small) sense request. This fixes some USB GSM modems
+		 */
+		if (temp_result == USB_STOR_TRANSPORT_FAILED &&
+				sense_size != US_SENSE_SIZE) {
+			usb_stor_dbg(us, "-- auto-sense failure, retry small sense\n");
+			sense_size = US_SENSE_SIZE;
+			us->fflags &= ~US_FL_SANE_SENSE;
+			us->fflags |= US_FL_BAD_SENSE;
+			goto Retry_Sense;
+		}
+
+		/* Other failures */
+		if (temp_result != USB_STOR_TRANSPORT_GOOD) {
+			usb_stor_dbg(us, "-- auto-sense failure\n");
+
+			/* we skip the reset if this happens to be a
+			 * multi-target device, since failure of an
+			 * auto-sense is perfectly valid
+			 */
+			srb->result = DID_ERROR << 16;
+			if (!(us->fflags & US_FL_SCM_MULT_TARG))
+				goto Handle_Errors;
+			return;
+		}
+
+		/* If the sense data returned is larger than 18-bytes then we
+		 * assume this device supports requesting more in the future.
+		 * The response code must be 70h through 73h inclusive.
+		 */
+		if (srb->sense_buffer[7] > (US_SENSE_SIZE - 8) &&
+		    !(us->fflags & US_FL_SANE_SENSE) &&
+		    !(us->fflags & US_FL_BAD_SENSE) &&
+		    (srb->sense_buffer[0] & 0x7C) == 0x70) {
+			usb_stor_dbg(us, "-- SANE_SENSE support enabled\n");
+			us->fflags |= US_FL_SANE_SENSE;
+
+			/* Indicate to the user that we truncated their sense
+			 * because we didn't know it supported larger sense.
+			 */
+			usb_stor_dbg(us, "-- Sense data truncated to %i from %i\n",
+				     US_SENSE_SIZE,
+				     srb->sense_buffer[7] + 8);
+			srb->sense_buffer[7] = (US_SENSE_SIZE - 8);
+		}
+
+		scsi_normalize_sense(srb->sense_buffer, SCSI_SENSE_BUFFERSIZE,
+				     &sshdr);
+
+		usb_stor_dbg(us, "-- Result from auto-sense is %d\n",
+			     temp_result);
+		usb_stor_dbg(us, "-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n",
+			     sshdr.response_code, sshdr.sense_key,
+			     sshdr.asc, sshdr.ascq);
+#ifdef CONFIG_USB_STORAGE_DEBUG
+		usb_stor_show_sense(us, sshdr.sense_key, sshdr.asc, sshdr.ascq);
+#endif
+
+		/* set the result so the higher layers expect this data */
+		srb->result = SAM_STAT_CHECK_CONDITION;
+
+		scdd = scsi_sense_desc_find(srb->sense_buffer,
+					    SCSI_SENSE_BUFFERSIZE, 4);
+		fm_ili = (scdd ? scdd[3] : srb->sense_buffer[2]) & 0xA0;
+
+		/* We often get empty sense data.  This could indicate that
+		 * everything worked or that there was an unspecified
+		 * problem.  We have to decide which.
+		 */
+		if (sshdr.sense_key == 0 && sshdr.asc == 0 && sshdr.ascq == 0 &&
+		    fm_ili == 0) {
+			/* If things are really okay, then let's show that.
+			 * Zero out the sense buffer so the higher layers
+			 * won't realize we did an unsolicited auto-sense.
+			 */
+			if (result == USB_STOR_TRANSPORT_GOOD) {
+				srb->result = SAM_STAT_GOOD;
+				srb->sense_buffer[0] = 0x0;
+
+			/* If there was a problem, report an unspecified
+			 * hardware error to prevent the higher layers from
+			 * entering an infinite retry loop.
+			 */
+			} else {
+				srb->result = DID_ERROR << 16;
+				if ((sshdr.response_code & 0x72) == 0x72)
+					srb->sense_buffer[1] = HARDWARE_ERROR;
+				else
+					srb->sense_buffer[2] = HARDWARE_ERROR;
+			}
+		}
+	}
+
+	/*
+	 * Some devices don't work or return incorrect data the first
+	 * time they get a READ(10) command, or for the first READ(10)
+	 * after a media change.  If the INITIAL_READ10 flag is set,
+	 * keep track of whether READ(10) commands succeed.  If the
+	 * previous one succeeded and this one failed, set the REDO_READ10
+	 * flag to force a retry.
+	 */
+	if (unlikely((us->fflags & US_FL_INITIAL_READ10) &&
+			srb->cmnd[0] == READ_10)) {
+		if (srb->result == SAM_STAT_GOOD) {
+			set_bit(US_FLIDX_READ10_WORKED, &us->dflags);
+		} else if (test_bit(US_FLIDX_READ10_WORKED, &us->dflags)) {
+			clear_bit(US_FLIDX_READ10_WORKED, &us->dflags);
+			set_bit(US_FLIDX_REDO_READ10, &us->dflags);
+		}
+
+		/*
+		 * Next, if the REDO_READ10 flag is set, return a result
+		 * code that will cause the SCSI core to retry the READ(10)
+		 * command immediately.
+		 */
+		if (test_bit(US_FLIDX_REDO_READ10, &us->dflags)) {
+			clear_bit(US_FLIDX_REDO_READ10, &us->dflags);
+			srb->result = DID_IMM_RETRY << 16;
+			srb->sense_buffer[0] = 0;
+		}
+	}
+
+	/* Did we transfer less than the minimum amount required? */
+	if ((srb->result == SAM_STAT_GOOD || srb->sense_buffer[2] == 0) &&
+			scsi_bufflen(srb) - scsi_get_resid(srb) < srb->underflow)
+		srb->result = DID_ERROR << 16;
+
+	last_sector_hacks(us, srb);
+	return;
+
+	/* Error and abort processing: try to resynchronize with the device
+	 * by issuing a port reset.  If that fails, try a class-specific
+	 * device reset. */
+  Handle_Errors:
+
+	/* Set the RESETTING bit, and clear the ABORTING bit so that
+	 * the reset may proceed. */
+	scsi_lock(us_to_host(us));
+	set_bit(US_FLIDX_RESETTING, &us->dflags);
+	clear_bit(US_FLIDX_ABORTING, &us->dflags);
+	scsi_unlock(us_to_host(us));
+
+	/* We must release the device lock because the pre_reset routine
+	 * will want to acquire it. */
+	mutex_unlock(&us->dev_mutex);
+	result = usb_stor_port_reset(us);
+	mutex_lock(&us->dev_mutex);
+
+	if (result < 0) {
+		scsi_lock(us_to_host(us));
+		usb_stor_report_device_reset(us);
+		scsi_unlock(us_to_host(us));
+		us->transport_reset(us);
+	}
+	clear_bit(US_FLIDX_RESETTING, &us->dflags);
+	last_sector_hacks(us, srb);
+}
+
+/* Stop the current URB transfer */
+void usb_stor_stop_transport(struct us_data *us)
+{
+	/* If the state machine is blocked waiting for an URB,
+	 * let's wake it up.  The test_and_clear_bit() call
+	 * guarantees that if a URB has just been submitted,
+	 * it won't be cancelled more than once. */
+	if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
+		usb_stor_dbg(us, "-- cancelling URB\n");
+		usb_unlink_urb(us->current_urb);
+	}
+
+	/* If we are waiting for a scatter-gather operation, cancel it. */
+	if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
+		usb_stor_dbg(us, "-- cancelling sg request\n");
+		usb_sg_cancel(&us->current_sg);
+	}
+}
+
+/*
+ * Control/Bulk and Control/Bulk/Interrupt transport
+ */
+
+int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
+{
+	unsigned int transfer_length = scsi_bufflen(srb);
+	unsigned int pipe = 0;
+	int result;
+
+	/* COMMAND STAGE */
+	/* let's send the command via the control pipe */
+	result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
+				      US_CBI_ADSC, 
+				      USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, 
+				      us->ifnum, srb->cmnd, srb->cmd_len);
+
+	/* check the return code for the command */
+	usb_stor_dbg(us, "Call to usb_stor_ctrl_transfer() returned %d\n",
+		     result);
+
+	/* if we stalled the command, it means command failed */
+	if (result == USB_STOR_XFER_STALLED) {
+		return USB_STOR_TRANSPORT_FAILED;
+	}
+
+	/* Uh oh... serious problem here */
+	if (result != USB_STOR_XFER_GOOD) {
+		return USB_STOR_TRANSPORT_ERROR;
+	}
+
+	/* DATA STAGE */
+	/* transfer the data payload for this command, if one exists*/
+	if (transfer_length) {
+		pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 
+				us->recv_bulk_pipe : us->send_bulk_pipe;
+		result = usb_stor_bulk_srb(us, pipe, srb);
+		usb_stor_dbg(us, "CBI data stage result is 0x%x\n", result);
+
+		/* if we stalled the data transfer it means command failed */
+		if (result == USB_STOR_XFER_STALLED)
+			return USB_STOR_TRANSPORT_FAILED;
+		if (result > USB_STOR_XFER_STALLED)
+			return USB_STOR_TRANSPORT_ERROR;
+	}
+
+	/* STATUS STAGE */
+
+	/* NOTE: CB does not have a status stage.  Silly, I know.  So
+	 * we have to catch this at a higher level.
+	 */
+	if (us->protocol != USB_PR_CBI)
+		return USB_STOR_TRANSPORT_GOOD;
+
+	result = usb_stor_intr_transfer(us, us->iobuf, 2);
+	usb_stor_dbg(us, "Got interrupt data (0x%x, 0x%x)\n",
+		     us->iobuf[0], us->iobuf[1]);
+	if (result != USB_STOR_XFER_GOOD)
+		return USB_STOR_TRANSPORT_ERROR;
+
+	/* UFI gives us ASC and ASCQ, like a request sense
+	 *
+	 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI
+	 * devices, so we ignore the information for those commands.  Note
+	 * that this means we could be ignoring a real error on these
+	 * commands, but that can't be helped.
+	 */
+	if (us->subclass == USB_SC_UFI) {
+		if (srb->cmnd[0] == REQUEST_SENSE ||
+		    srb->cmnd[0] == INQUIRY)
+			return USB_STOR_TRANSPORT_GOOD;
+		if (us->iobuf[0])
+			goto Failed;
+		return USB_STOR_TRANSPORT_GOOD;
+	}
+
+	/* If not UFI, we interpret the data as a result code 
+	 * The first byte should always be a 0x0.
+	 *
+	 * Some bogus devices don't follow that rule.  They stuff the ASC
+	 * into the first byte -- so if it's non-zero, call it a failure.
+	 */
+	if (us->iobuf[0]) {
+		usb_stor_dbg(us, "CBI IRQ data showed reserved bType 0x%x\n",
+			     us->iobuf[0]);
+		goto Failed;
+
+	}
+
+	/* The second byte & 0x0F should be 0x0 for good, otherwise error */
+	switch (us->iobuf[1] & 0x0F) {
+		case 0x00: 
+			return USB_STOR_TRANSPORT_GOOD;
+		case 0x01: 
+			goto Failed;
+	}
+	return USB_STOR_TRANSPORT_ERROR;
+
+	/* the CBI spec requires that the bulk pipe must be cleared
+	 * following any data-in/out command failure (section 2.4.3.1.3)
+	 */
+  Failed:
+	if (pipe)
+		usb_stor_clear_halt(us, pipe);
+	return USB_STOR_TRANSPORT_FAILED;
+}
+EXPORT_SYMBOL_GPL(usb_stor_CB_transport);
+
+/*
+ * Bulk only transport
+ */
+
+/* Determine what the maximum LUN supported is */
+int usb_stor_Bulk_max_lun(struct us_data *us)
+{
+	int result;
+
+	/* issue the command */
+	us->iobuf[0] = 0;
+	result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
+				 US_BULK_GET_MAX_LUN, 
+				 USB_DIR_IN | USB_TYPE_CLASS | 
+				 USB_RECIP_INTERFACE,
+				 0, us->ifnum, us->iobuf, 1, 10*HZ);
+
+	usb_stor_dbg(us, "GetMaxLUN command result is %d, data is %d\n",
+		     result, us->iobuf[0]);
+
+	/*
+	 * If we have a successful request, return the result if valid. The
+	 * CBW LUN field is 4 bits wide, so the value reported by the device
+	 * should fit into that.
+	 */
+	if (result > 0) {
+		if (us->iobuf[0] < 16) {
+			return us->iobuf[0];
+		} else {
+			dev_info(&us->pusb_intf->dev,
+				 "Max LUN %d is not valid, using 0 instead",
+				 us->iobuf[0]);
+		}
+	}
+
+	/*
+	 * Some devices don't like GetMaxLUN.  They may STALL the control
+	 * pipe, they may return a zero-length result, they may do nothing at
+	 * all and timeout, or they may fail in even more bizarrely creative
+	 * ways.  In these cases the best approach is to use the default
+	 * value: only one LUN.
+	 */
+	return 0;
+}
+
+int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
+{
+	struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
+	struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
+	unsigned int transfer_length = scsi_bufflen(srb);
+	unsigned int residue;
+	int result;
+	int fake_sense = 0;
+	unsigned int cswlen;
+	unsigned int cbwlen = US_BULK_CB_WRAP_LEN;
+
+	/* Take care of BULK32 devices; set extra byte to 0 */
+	if (unlikely(us->fflags & US_FL_BULK32)) {
+		cbwlen = 32;
+		us->iobuf[31] = 0;
+	}
+
+	/* set up the command wrapper */
+	bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
+	bcb->DataTransferLength = cpu_to_le32(transfer_length);
+	bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ?
+		US_BULK_FLAG_IN : 0;
+	bcb->Tag = ++us->tag;
+	bcb->Lun = srb->device->lun;
+	if (us->fflags & US_FL_SCM_MULT_TARG)
+		bcb->Lun |= srb->device->id << 4;
+	bcb->Length = srb->cmd_len;
+
+	/* copy the command payload */
+	memset(bcb->CDB, 0, sizeof(bcb->CDB));
+	memcpy(bcb->CDB, srb->cmnd, bcb->Length);
+
+	/* send it to out endpoint */
+	usb_stor_dbg(us, "Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n",
+		     le32_to_cpu(bcb->Signature), bcb->Tag,
+		     le32_to_cpu(bcb->DataTransferLength), bcb->Flags,
+		     (bcb->Lun >> 4), (bcb->Lun & 0x0F),
+		     bcb->Length);
+	result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
+				bcb, cbwlen, NULL);
+	usb_stor_dbg(us, "Bulk command transfer result=%d\n", result);
+	if (result != USB_STOR_XFER_GOOD)
+		return USB_STOR_TRANSPORT_ERROR;
+
+	/* DATA STAGE */
+	/* send/receive data payload, if there is any */
+
+	/* Some USB-IDE converter chips need a 100us delay between the
+	 * command phase and the data phase.  Some devices need a little
+	 * more than that, probably because of clock rate inaccuracies. */
+	if (unlikely(us->fflags & US_FL_GO_SLOW))
+		udelay(125);
+
+	if (transfer_length) {
+		unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 
+				us->recv_bulk_pipe : us->send_bulk_pipe;
+		result = usb_stor_bulk_srb(us, pipe, srb);
+		usb_stor_dbg(us, "Bulk data transfer result 0x%x\n", result);
+		if (result == USB_STOR_XFER_ERROR)
+			return USB_STOR_TRANSPORT_ERROR;
+
+		/* If the device tried to send back more data than the
+		 * amount requested, the spec requires us to transfer
+		 * the CSW anyway.  Since there's no point retrying the
+		 * the command, we'll return fake sense data indicating
+		 * Illegal Request, Invalid Field in CDB.
+		 */
+		if (result == USB_STOR_XFER_LONG)
+			fake_sense = 1;
+
+		/*
+		 * Sometimes a device will mistakenly skip the data phase
+		 * and go directly to the status phase without sending a
+		 * zero-length packet.  If we get a 13-byte response here,
+		 * check whether it really is a CSW.
+		 */
+		if (result == USB_STOR_XFER_SHORT &&
+				srb->sc_data_direction == DMA_FROM_DEVICE &&
+				transfer_length - scsi_get_resid(srb) ==
+					US_BULK_CS_WRAP_LEN) {
+			struct scatterlist *sg = NULL;
+			unsigned int offset = 0;
+
+			if (usb_stor_access_xfer_buf((unsigned char *) bcs,
+					US_BULK_CS_WRAP_LEN, srb, &sg,
+					&offset, FROM_XFER_BUF) ==
+						US_BULK_CS_WRAP_LEN &&
+					bcs->Signature ==
+						cpu_to_le32(US_BULK_CS_SIGN)) {
+				usb_stor_dbg(us, "Device skipped data phase\n");
+				scsi_set_resid(srb, transfer_length);
+				goto skipped_data_phase;
+			}
+		}
+	}
+
+	/* See flow chart on pg 15 of the Bulk Only Transport spec for
+	 * an explanation of how this code works.
+	 */
+
+	/* get CSW for device status */
+	usb_stor_dbg(us, "Attempting to get CSW...\n");
+	result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
+				bcs, US_BULK_CS_WRAP_LEN, &cswlen);
+
+	/* 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 (result == USB_STOR_XFER_SHORT && cswlen == 0) {
+		usb_stor_dbg(us, "Received 0-length CSW; retrying...\n");
+		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
+				bcs, US_BULK_CS_WRAP_LEN, &cswlen);
+	}
+
+	/* did the attempt to read the CSW fail? */
+	if (result == USB_STOR_XFER_STALLED) {
+
+		/* get the status again */
+		usb_stor_dbg(us, "Attempting to get CSW (2nd try)...\n");
+		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
+				bcs, US_BULK_CS_WRAP_LEN, NULL);
+	}
+
+	/* if we still have a failure at this point, we're in trouble */
+	usb_stor_dbg(us, "Bulk status result = %d\n", result);
+	if (result != USB_STOR_XFER_GOOD)
+		return USB_STOR_TRANSPORT_ERROR;
+
+ skipped_data_phase:
+	/* check bulk status */
+	residue = le32_to_cpu(bcs->Residue);
+	usb_stor_dbg(us, "Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",
+		     le32_to_cpu(bcs->Signature), bcs->Tag,
+		     residue, bcs->Status);
+	if (!(bcs->Tag == us->tag || (us->fflags & US_FL_BULK_IGNORE_TAG)) ||
+		bcs->Status > US_BULK_STAT_PHASE) {
+		usb_stor_dbg(us, "Bulk logical error\n");
+		return USB_STOR_TRANSPORT_ERROR;
+	}
+
+	/* Some broken devices report odd signatures, so we do not check them
+	 * for validity against the spec. We store the first one we see,
+	 * and check subsequent transfers for validity against this signature.
+	 */
+	if (!us->bcs_signature) {
+		us->bcs_signature = bcs->Signature;
+		if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN))
+			usb_stor_dbg(us, "Learnt BCS signature 0x%08X\n",
+				     le32_to_cpu(us->bcs_signature));
+	} else if (bcs->Signature != us->bcs_signature) {
+		usb_stor_dbg(us, "Signature mismatch: got %08X, expecting %08X\n",
+			     le32_to_cpu(bcs->Signature),
+			     le32_to_cpu(us->bcs_signature));
+		return USB_STOR_TRANSPORT_ERROR;
+	}
+
+	/* try to compute the actual residue, based on how much data
+	 * was really transferred and what the device tells us */
+	if (residue && !(us->fflags & US_FL_IGNORE_RESIDUE)) {
+
+		/* Heuristically detect devices that generate bogus residues
+		 * by seeing what happens with INQUIRY and READ CAPACITY
+		 * commands.
+		 */
+		if (bcs->Status == US_BULK_STAT_OK &&
+				scsi_get_resid(srb) == 0 &&
+					((srb->cmnd[0] == INQUIRY &&
+						transfer_length == 36) ||
+					(srb->cmnd[0] == READ_CAPACITY &&
+						transfer_length == 8))) {
+			us->fflags |= US_FL_IGNORE_RESIDUE;
+
+		} else {
+			residue = min(residue, transfer_length);
+			scsi_set_resid(srb, max(scsi_get_resid(srb),
+			                                       (int) residue));
+		}
+	}
+
+	/* based on the status code, we report good or bad */
+	switch (bcs->Status) {
+		case US_BULK_STAT_OK:
+			/* device babbled -- return fake sense data */
+			if (fake_sense) {
+				memcpy(srb->sense_buffer, 
+				       usb_stor_sense_invalidCDB, 
+				       sizeof(usb_stor_sense_invalidCDB));
+				return USB_STOR_TRANSPORT_NO_SENSE;
+			}
+
+			/* command good -- note that data could be short */
+			return USB_STOR_TRANSPORT_GOOD;
+
+		case US_BULK_STAT_FAIL:
+			/* command failed */
+			return USB_STOR_TRANSPORT_FAILED;
+
+		case US_BULK_STAT_PHASE:
+			/* phase error -- note that a transport reset will be
+			 * invoked by the invoke_transport() function
+			 */
+			return USB_STOR_TRANSPORT_ERROR;
+	}
+
+	/* we should never get here, but if we do, we're in trouble */
+	return USB_STOR_TRANSPORT_ERROR;
+}
+EXPORT_SYMBOL_GPL(usb_stor_Bulk_transport);
+
+/***********************************************************************
+ * Reset routines
+ ***********************************************************************/
+
+/* This is the common part of the device reset code.
+ *
+ * It's handy that every transport mechanism uses the control endpoint for
+ * resets.
+ *
+ * Basically, we send a reset with a 5-second timeout, so we don't get
+ * jammed attempting to do the reset.
+ */
+static int usb_stor_reset_common(struct us_data *us,
+		u8 request, u8 requesttype,
+		u16 value, u16 index, void *data, u16 size)
+{
+	int result;
+	int result2;
+
+	if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
+		usb_stor_dbg(us, "No reset during disconnect\n");
+		return -EIO;
+	}
+
+	result = usb_stor_control_msg(us, us->send_ctrl_pipe,
+			request, requesttype, value, index, data, size,
+			5*HZ);
+	if (result < 0) {
+		usb_stor_dbg(us, "Soft reset failed: %d\n", result);
+		return result;
+	}
+
+	/* Give the device some time to recover from the reset,
+	 * but don't delay disconnect processing. */
+	wait_event_interruptible_timeout(us->delay_wait,
+			test_bit(US_FLIDX_DISCONNECTING, &us->dflags),
+			HZ*6);
+	if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
+		usb_stor_dbg(us, "Reset interrupted by disconnect\n");
+		return -EIO;
+	}
+
+	usb_stor_dbg(us, "Soft reset: clearing bulk-in endpoint halt\n");
+	result = usb_stor_clear_halt(us, us->recv_bulk_pipe);
+
+	usb_stor_dbg(us, "Soft reset: clearing bulk-out endpoint halt\n");
+	result2 = usb_stor_clear_halt(us, us->send_bulk_pipe);
+
+	/* return a result code based on the result of the clear-halts */
+	if (result >= 0)
+		result = result2;
+	if (result < 0)
+		usb_stor_dbg(us, "Soft reset failed\n");
+	else
+		usb_stor_dbg(us, "Soft reset done\n");
+	return result;
+}
+
+/* This issues a CB[I] Reset to the device in question
+ */
+#define CB_RESET_CMD_SIZE	12
+
+int usb_stor_CB_reset(struct us_data *us)
+{
+	memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE);
+	us->iobuf[0] = SEND_DIAGNOSTIC;
+	us->iobuf[1] = 4;
+	return usb_stor_reset_common(us, US_CBI_ADSC, 
+				 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+				 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE);
+}
+EXPORT_SYMBOL_GPL(usb_stor_CB_reset);
+
+/* This issues a Bulk-only Reset to the device in question, including
+ * clearing the subsequent endpoint halts that may occur.
+ */
+int usb_stor_Bulk_reset(struct us_data *us)
+{
+	return usb_stor_reset_common(us, US_BULK_RESET_REQUEST, 
+				 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
+				 0, us->ifnum, NULL, 0);
+}
+EXPORT_SYMBOL_GPL(usb_stor_Bulk_reset);
+
+/* Issue a USB port reset to the device.  The caller must not hold
+ * us->dev_mutex.
+ */
+int usb_stor_port_reset(struct us_data *us)
+{
+	int result;
+
+	/*for these devices we must use the class specific method */
+	if (us->pusb_dev->quirks & USB_QUIRK_RESET)
+		return -EPERM;
+
+	result = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
+	if (result < 0)
+		usb_stor_dbg(us, "unable to lock device for reset: %d\n",
+			     result);
+	else {
+		/* Were we disconnected while waiting for the lock? */
+		if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
+			result = -EIO;
+			usb_stor_dbg(us, "No reset during disconnect\n");
+		} else {
+			result = usb_reset_device(us->pusb_dev);
+			usb_stor_dbg(us, "usb_reset_device returns %d\n",
+				     result);
+		}
+		usb_unlock_device(us->pusb_dev);
+	}
+	return result;
+}