[PATCH] USB Storage: change how INQUIRY is fixed up

The usb-storage driver 'fixes up' the INQUIRY data returned by a device so
that it reads SCSI rev 2 by intercepting the data in-flight.  This was done
to make various SCSI drivers (sd, sr, etc.) work with the device.

However, this technique also has the unfortunate side-effect that nobody
can see the real rev. -- not even sg users.

This patch changes that.  Now, the SCSI revision is changed in the
slave_configure() function.  Thus, the 'real' data is available to anyone
who wants to issue an INQUIRY directly via any means.

This also simplifies the code somewhat.
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>

drivers/usb/storage/isd200.c

@@ -1052,12 +1052,6 @@ static int isd200_get_inquiry_data( struct us_data *us )
 				/* Standard IDE interface only supports disks */
 				info->InquiryData.DeviceType = DIRECT_ACCESS_DEVICE;
 
-				/* Fix-up the return data from an INQUIRY command to show 
-				 * ANSI SCSI rev 2 so we don't confuse the SCSI layers above us
-				 * in Linux.
-				 */
-				info->InquiryData.Versions = 0x2;
-
 				/* The length must be at least 36 (5 + 31) */
 				info->InquiryData.AdditionalLength = 0x1F;
 

drivers/usb/storage/protocol.c

@@ -57,38 +57,6 @@
  * Helper routines
  ***********************************************************************/
 
-/*
- * Fix-up the return data from an INQUIRY command to show 
- * ANSI SCSI rev 2 so we don't confuse the SCSI layers above us
- */
-static void fix_inquiry_data(struct scsi_cmnd *srb)
-{
-	unsigned char databuf[3];
-	unsigned int index, offset;
-
-	/* verify that it's an INQUIRY command */
-	if (srb->cmnd[0] != INQUIRY)
-		return;
-
-	index = offset = 0;
-	if (usb_stor_access_xfer_buf(databuf, sizeof(databuf), srb,
-			&index, &offset, FROM_XFER_BUF) != sizeof(databuf))
-		return;
-
-	if ((databuf[2] & 7) == 2)
-		return;
-
-	US_DEBUGP("Fixing INQUIRY data to show SCSI rev 2 - was %d\n",
-		  databuf[2] & 7);
-
-	/* Change the SCSI revision number */
-	databuf[2] = (databuf[2] & ~7) | 2;
-
-	index = offset = 0;
-	usb_stor_access_xfer_buf(databuf, sizeof(databuf), srb,
-			&index, &offset, TO_XFER_BUF);
-}
-
 /*
  * Fix-up the return data from a READ CAPACITY command. My Feiya reader
  * returns a value that is 1 too large.
@@ -137,10 +105,6 @@ void usb_stor_qic157_command(struct scsi_cmnd *srb, struct us_data *us)
 
 	/* send the command to the transport layer */
 	usb_stor_invoke_transport(srb, us);
-	if (srb->result == SAM_STAT_GOOD) {
-		/* fix the INQUIRY data if necessary */
-		fix_inquiry_data(srb);
-	}
 }
 
 void usb_stor_ATAPI_command(struct scsi_cmnd *srb, struct us_data *us)
@@ -160,11 +124,6 @@ void usb_stor_ATAPI_command(struct scsi_cmnd *srb, struct us_data *us)
 
 	/* send the command to the transport layer */
 	usb_stor_invoke_transport(srb, us);
-
-	if (srb->result == SAM_STAT_GOOD) {
-		/* fix the INQUIRY data if necessary */
-		fix_inquiry_data(srb);
-	}
 }
 
 
@@ -208,11 +167,6 @@ void usb_stor_ufi_command(struct scsi_cmnd *srb, struct us_data *us)
 
 	/* send the command to the transport layer */
 	usb_stor_invoke_transport(srb, us);
-
-	if (srb->result == SAM_STAT_GOOD) {
-		/* Fix the data for an INQUIRY, if necessary */
-		fix_inquiry_data(srb);
-	}
 }
 
 void usb_stor_transparent_scsi_command(struct scsi_cmnd *srb,
@@ -222,9 +176,6 @@ void usb_stor_transparent_scsi_command(struct scsi_cmnd *srb,
 	usb_stor_invoke_transport(srb, us);
 
 	if (srb->result == SAM_STAT_GOOD) {
-		/* Fix the INQUIRY data if necessary */
-		fix_inquiry_data(srb);
-
 		/* Fix the READ CAPACITY result if necessary */
 		if (us->flags & US_FL_FIX_CAPACITY)
 			fix_read_capacity(srb);

drivers/usb/storage/scsiglue.c

@@ -98,6 +98,23 @@ static int slave_configure(struct scsi_device *sdev)
 	 * the end, scatter-gather buffers follow page boundaries. */
 	blk_queue_dma_alignment(sdev->request_queue, (512 - 1));
 
+	/* Set the SCSI level to at least 2.  We'll leave it at 3 if that's
+	 * what is originally reported.  We need this to avoid confusing
+	 * the SCSI layer with devices that report 0 or 1, but need 10-byte
+	 * commands (ala ATAPI devices behind certain bridges, or devices
+	 * which simply have broken INQUIRY data).
+	 *
+	 * NOTE: This means /dev/sg programs (ala cdrecord) will get the
+	 * actual information.  This seems to be the preference for
+	 * programs like that.
+	 *
+	 * NOTE: This also means that /proc/scsi/scsi and sysfs may report
+	 * the actual value or the modified one, depending on where the
+	 * data comes from.
+	 */
+	if (sdev->scsi_level < SCSI_2)
+		sdev->scsi_level = SCSI_2;
+
 	/* According to the technical support people at Genesys Logic,
 	 * devices using their chips have problems transferring more than
 	 * 32 KB at a time.  In practice people have found that 64 KB