[PATCH] USB storage: remove usb_stor_tranfer_length()

This patch removes the (often troublesome) usb_stor_transfer_length()
function.

We've finally gotten all the command initiators to send the correct values
in the srb->request_bufflen field, so this is no longer needed.

There are probably some sanity checks that can also be removed now, but
that's for a later patch.

drivers/usb/storage/freecom.c

@@ -285,7 +285,7 @@ int freecom_transport(Scsi_Cmnd *srb, struct us_data *us)
          * and such will hang. */
         US_DEBUGP("Device indicates that it has %d bytes available\n",
                         le16_to_cpu (fst->Count));
-        US_DEBUGP("SCSI requested %d\n", usb_stor_transfer_length(srb));
+        US_DEBUGP("SCSI requested %d\n", srb->request_bufflen);
 
         /* Find the length we desire to read. */
 	switch (srb->cmnd[0]) {
@@ -296,7 +296,7 @@ int freecom_transport(Scsi_Cmnd *srb, struct us_data *us)
 			length = fst->Count;
 			break;
 		default:
- 			length = usb_stor_transfer_length (srb);
+ 			length = srb->request_bufflen;
 	}
 
 	/* verify that this amount is legal */

drivers/usb/storage/transport.c

@@ -55,307 +55,6 @@
 #include <linux/errno.h>
 #include <linux/slab.h>
 
-/***********************************************************************
- * Helper routines
- ***********************************************************************/
-
-/* Calculate the length of the data transfer (not the command) for any
- * given SCSI command
- */
-unsigned int usb_stor_transfer_length(Scsi_Cmnd *srb)
-{
-      	int i;
-	int doDefault = 0;
-	unsigned int len = 0;
-	unsigned int total = 0;
-	struct scatterlist *sg;
-
-	/* This table tells us:
-	   X = command not supported
-	   L = return length in cmnd[4] (8 bits).
-	   M = return length in cmnd[8] (8 bits).
-	   G = return length in cmnd[3] and cmnd[4] (16 bits)
-	   H = return length in cmnd[7] and cmnd[8] (16 bits)
-	   I = return length in cmnd[8] and cmnd[9] (16 bits)
-	   C = return length in cmnd[2] to cmnd[5] (32 bits)
-	   D = return length in cmnd[6] to cmnd[9] (32 bits)
-	   B = return length in blocksize so we use buff_len
-	   R = return length in cmnd[2] to cmnd[4] (24 bits)
-	   S = return length in cmnd[3] to cmnd[5] (24 bits)
-	   T = return length in cmnd[6] to cmnd[8] (24 bits)
-	   U = return length in cmnd[7] to cmnd[9] (24 bits)
-	   0-9 = fixed return length
-	   V = 20 bytes
-	   W = 24 bytes
-	   Z = return length is mode dependant or not in command, use buff_len
-	*/
-
-	static char *lengths =
-
-	      /* 0123456789ABCDEF   0123456789ABCDEF */
-
-		"00XLZ6XZBXBBXXXB" "00LBBLG0R0L0GG0X"  /* 00-1F */
-		"XXXXT8XXB4B0BBBB" "ZZZ0B00HCSSZTBHH"  /* 20-3F */
-		"M0HHB0X000H0HH0X" "XHH0HHXX0TH0H0XX"  /* 40-5F */
-		"XXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXX"  /* 60-7F */
-		"XXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXX"  /* 80-9F */
-		"X0XXX00XB0BXBXBB" "ZZZ0XUIDU000XHBX"  /* A0-BF */
-		"XXXXXXXXXXXXXXXX" "XXXXXXXXXXXXXXXX"  /* C0-DF */
-		"XDXXXXXXXXXXXXXX" "XXW00HXXXXXXXXXX"; /* E0-FF */
-
-	/* Commands checked in table:
-
-	   CHANGE_DEFINITION 40
-	   COMPARE 39
-	   COPY 18
-	   COPY_AND_VERIFY 3a
-	   ERASE 19
-	   ERASE_10 2c
-	   ERASE_12 ac
-	   EXCHANGE_MEDIUM a6
-	   FORMAT_UNIT 04
-	   GET_DATA_BUFFER_STATUS 34
-	   GET_MESSAGE_10 28
-	   GET_MESSAGE_12 a8
-	   GET_WINDOW 25   !!! Has more data than READ_CAPACITY, need to fix table
-	   INITIALIZE_ELEMENT_STATUS 07 !!! REASSIGN_BLOCKS luckily uses buff_len
-	   INQUIRY 12
-	   LOAD_UNLOAD 1b
-	   LOCATE 2b
-	   LOCK_UNLOCK_CACHE 36
-	   LOG_SELECT 4c
-	   LOG_SENSE 4d
-	   MEDIUM_SCAN 38     !!! This was M
-	   MODE_SELECT6 15
-	   MODE_SELECT_10 55
-	   MODE_SENSE_6 1a
-	   MODE_SENSE_10 5a
-	   MOVE_MEDIUM a5
-	   OBJECT_POSITION 31  !!! Same as SEARCH_DATA_EQUAL
-	   PAUSE_RESUME 4b
-	   PLAY_AUDIO_10 45
-	   PLAY_AUDIO_12 a5
-	   PLAY_AUDIO_MSF 47
-	   PLAY_AUDIO_TRACK_INDEX 48
-   	   PLAY_AUDIO_TRACK_RELATIVE_10 49
-	   PLAY_AUDIO_TRACK_RELATIVE_12 a9
-	   POSITION_TO_ELEMENT 2b
-      	   PRE-FETCH 34
-	   PREVENT_ALLOW_MEDIUM_REMOVAL 1e
-	   PRINT 0a             !!! Same as WRITE_6 but is always in bytes
-	   READ_6 08
-	   READ_10 28
-	   READ_12 a8
-	   READ_BLOCK_LIMITS 05
-	   READ_BUFFER 3c
-	   READ_CAPACITY 25
-	   READ_CDROM_CAPACITY 25
-	   READ_DEFECT_DATA 37
-	   READ_DEFECT_DATA_12 b7
-	   READ_ELEMENT_STATUS b8 !!! Think this is in bytes
-	   READ_GENERATION 29 !!! Could also be M?
-	   READ_HEADER 44     !!! This was L
-	   READ_LONG 3e
-	   READ_POSITION 34   !!! This should be V but conflicts with PRE-FETCH
-	   READ_REVERSE 0f
-	   READ_SUB-CHANNEL 42 !!! Is this in bytes?
-	   READ_TOC 43         !!! Is this in bytes?
-	   READ_UPDATED_BLOCK 2d
-	   REASSIGN_BLOCKS 07
-	   RECEIVE 08        !!! Same as READ_6 probably in bytes though
-	   RECEIVE_DIAGNOSTIC_RESULTS 1c
-	   RECOVER_BUFFERED_DATA 14 !!! For PRINTERs this is bytes
-	   RELEASE_UNIT 17
-	   REQUEST_SENSE 03
-	   REQUEST_VOLUME_ELEMENT_ADDRESS b5 !!! Think this is in bytes
-	   RESERVE_UNIT 16
-	   REWIND 01
-	   REZERO_UNIT 01
-	   SCAN 1b          !!! Conflicts with various commands, should be L
-	   SEARCH_DATA_EQUAL 31
-	   SEARCH_DATA_EQUAL_12 b1
-	   SEARCH_DATA_LOW 30
-	   SEARCH_DATA_LOW_12 b0
-	   SEARCH_DATA_HIGH 32
-	   SEARCH_DATA_HIGH_12 b2
-	   SEEK_6 0b         !!! Conflicts with SLEW_AND_PRINT
-	   SEEK_10 2b
-	   SEND 0a           !!! Same as WRITE_6, probably in bytes though
-	   SEND 2a           !!! Similar to WRITE_10 but for scanners
-	   SEND_DIAGNOSTIC 1d
-	   SEND_MESSAGE_6 0a   !!! Same as WRITE_6 - is in bytes
-	   SEND_MESSAGE_10 2a  !!! Same as WRITE_10 - is in bytes
-	   SEND_MESSAGE_12 aa  !!! Same as WRITE_12 - is in bytes
-	   SEND_OPC 54
-	   SEND_VOLUME_TAG b6 !!! Think this is in bytes
-	   SET_LIMITS 33
-	   SET_LIMITS_12 b3
-	   SET_WINDOW 24
-	   SLEW_AND_PRINT 0b !!! Conflicts with SEEK_6
-	   SPACE 11
-	   START_STOP_UNIT 1b
-	   STOP_PRINT 1b
-	   SYNCHRONIZE_BUFFER 10
-	   SYNCHRONIZE_CACHE 35
-	   TEST_UNIT_READY 00
-	   UPDATE_BLOCK 3d
-	   VERIFY 13
-	   VERIFY 2f
-	   VERIFY_12 af
-	   WRITE_6 0a
-	   WRITE_10 2a
-	   WRITE_12 aa
-	   WRITE_AND_VERIFY 2e
-	   WRITE_AND_VERIFY_12 ae
-	   WRITE_BUFFER 3b
-	   WRITE_FILEMARKS 10
-	   WRITE_LONG 3f
-	   WRITE_SAME 41
-	*/
-
-	if (srb->sc_data_direction == SCSI_DATA_WRITE) {
-		doDefault = 1;
-	}
-	else
-		switch (lengths[srb->cmnd[0]]) {
-			case 'L':
-				len = srb->cmnd[4];
-				break;
-
-			case 'M':
-				len = srb->cmnd[8];
-				break;
-
-			case '0':
-			case '1':
-			case '2':
-			case '3':
-			case '4':
-			case '5':
-			case '6':
-			case '7':
-			case '8':
-			case '9':
-				len = lengths[srb->cmnd[0]]-'0';
-				break;
-
-			case 'G':
-				len = (((unsigned int)srb->cmnd[3])<<8) |
-					srb->cmnd[4];
-				break;
-
-			case 'H':
-				len = (((unsigned int)srb->cmnd[7])<<8) |
-					srb->cmnd[8];
-				break;
-
-			case 'I':
-				len = (((unsigned int)srb->cmnd[8])<<8) |
-					srb->cmnd[9];
-				break;
-
-			case 'R':
-				len = (((unsigned int)srb->cmnd[2])<<16) |
-					(((unsigned int)srb->cmnd[3])<<8) |
-					srb->cmnd[4];
-				break;
-
-			case 'S':
-				len = (((unsigned int)srb->cmnd[3])<<16) |
-					(((unsigned int)srb->cmnd[4])<<8) |
-					srb->cmnd[5];
-				break;
-
-			case 'T':
-				len = (((unsigned int)srb->cmnd[6])<<16) |
-					(((unsigned int)srb->cmnd[7])<<8) |
-					srb->cmnd[8];
-				break;
-
-			case 'U':
-				len = (((unsigned int)srb->cmnd[7])<<16) |
-					(((unsigned int)srb->cmnd[8])<<8) |
-					srb->cmnd[9];
-				break;
-
-			case 'C':
-				len = (((unsigned int)srb->cmnd[2])<<24) |
-					(((unsigned int)srb->cmnd[3])<<16) |
-					(((unsigned int)srb->cmnd[4])<<8) |
-					srb->cmnd[5];
-				break;
-
-			case 'D':
-				len = (((unsigned int)srb->cmnd[6])<<24) |
-					(((unsigned int)srb->cmnd[7])<<16) |
-					(((unsigned int)srb->cmnd[8])<<8) |
-					srb->cmnd[9];
-				break;
-
-			case 'V':
-				len = 20;
-				break;
-
-			case 'W':
-				len = 24;
-				break;
-
-			case 'B':
-				/* Use buffer size due to different block sizes */
-				doDefault = 1;
-				break;
-
-			case 'X':
-				US_DEBUGP("Error: UNSUPPORTED COMMAND %02X\n",
-						srb->cmnd[0]);
-				doDefault = 1;
-				break;
-
-			case 'Z':
-				/* Use buffer size due to mode dependence */
-				doDefault = 1;
-				break;
-
-			default:
-				US_DEBUGP("Error: COMMAND %02X out of range or table inconsistent (%c).\n",
-						srb->cmnd[0], lengths[srb->cmnd[0]] );
-				doDefault = 1;
-		}
-	   
-	   if ( doDefault == 1 ) {
-		   /* Are we going to scatter gather? */
-		   if (srb->use_sg) {
-			   /* Add up the sizes of all the sg segments */
-			   sg = (struct scatterlist *) srb->request_buffer;
-			   for (i = 0; i < srb->use_sg; i++)
-				   total += sg[i].length;
-			   len = total;
-
-			   /* Double-check to see if the advertised buffer
-			    * length less than the actual buffer length --
-			    * in other words, we should tend towards the
-			    * conservative side for data transfers.
-			    */
-			   if (len > srb->request_bufflen)
-				   len = srb->request_bufflen;
-		   }
-		   else
-			   /* Just return the length of the buffer */
-			   len = srb->request_bufflen;
-	   }
-
-	/* According to the linux-scsi people, any command sent which
-	 * violates this invariant is a bug.  In the hopes of removing
-	 * all the complex logic above, let's find them and eliminate them.
-	 */
-	if (len != srb->request_bufflen) {
-		printk(KERN_ERR "USB len=%d, request_bufflen=%d\n", len, srb->request_bufflen);
-		dump_stack();
-	}
-
-	return len;
-}
-
 /***********************************************************************
  * Data transfer routines
  ***********************************************************************/
@@ -1031,7 +730,7 @@ void usb_stor_abort_transport(struct us_data *us)
 
 int usb_stor_CBI_transport(Scsi_Cmnd *srb, struct us_data *us)
 {
-	unsigned int transfer_length = usb_stor_transfer_length(srb);
+	unsigned int transfer_length = srb->request_bufflen;
 	int result;
 
 	/* COMMAND STAGE */
@@ -1115,7 +814,7 @@ int usb_stor_CBI_transport(Scsi_Cmnd *srb, struct us_data *us)
  */
 int usb_stor_CB_transport(Scsi_Cmnd *srb, struct us_data *us)
 {
-	unsigned int transfer_length = usb_stor_transfer_length(srb);
+	unsigned int transfer_length = srb->request_bufflen;
 	int result;
 
 	/* COMMAND STAGE */
@@ -1186,7 +885,7 @@ int usb_stor_Bulk_transport(Scsi_Cmnd *srb, struct us_data *us)
 {
 	struct bulk_cb_wrap bcb;
 	struct bulk_cs_wrap bcs;
-	unsigned int transfer_length = usb_stor_transfer_length(srb);
+	unsigned int transfer_length = srb->request_bufflen;
 	int result;
 
 	/* set up the command wrapper */

drivers/usb/storage/transport.h

@@ -154,7 +154,6 @@ extern int usb_stor_Bulk_transport(Scsi_Cmnd*, struct us_data*);
 extern int usb_stor_Bulk_max_lun(struct us_data*);
 extern int usb_stor_Bulk_reset(struct us_data*);
 
-extern unsigned int usb_stor_transfer_length(Scsi_Cmnd*);
 extern void usb_stor_invoke_transport(Scsi_Cmnd*, struct us_data*);
 extern void usb_stor_abort_transport(struct us_data*);