[PATCH] REQUEST SENSE 254->252 byte response

SPC-3 (rev 13) says that 252 bytes in the maximum (and
recommended) length for a REQUEST SENSE reponse.

Linux asks for 254 bytes in scsi_error.c .

That number was not specified in SPC-2 (although the
allocation length field is 1 byte thus limiting it to
255). Seems as though some numbers are being rounded
down to be multiples of 4.

drivers/scsi/scsi_error.c

@@ -532,14 +532,14 @@ static int scsi_send_eh_cmnd(struct scsi_cmnd *scmd, int timeout)
 static int scsi_request_sense(struct scsi_cmnd *scmd)
 {
 	static unsigned char generic_sense[6] =
-	{REQUEST_SENSE, 0, 0, 0, 254, 0};
+	{REQUEST_SENSE, 0, 0, 0, 252, 0};
 	unsigned char *scsi_result;
 	int saved_result;
 	int rtn;
 
 	memcpy(scmd->cmnd, generic_sense, sizeof(generic_sense));
 
-	scsi_result = kmalloc(254, GFP_ATOMIC | (scmd->device->host->hostt->unchecked_isa_dma) ? __GFP_DMA : 0);
+	scsi_result = kmalloc(252, GFP_ATOMIC | (scmd->device->host->hostt->unchecked_isa_dma) ? __GFP_DMA : 0);
 
 
 	if (unlikely(!scsi_result)) {
@@ -555,11 +555,11 @@ static int scsi_request_sense(struct scsi_cmnd *scmd)
 	 * address (db).  0 is not a valid sense code. 
 	 */
 	memset(scmd->sense_buffer, 0, sizeof(scmd->sense_buffer));
-	memset(scsi_result, 0, 254);
+	memset(scsi_result, 0, 252);
 
 	saved_result = scmd->result;
 	scmd->request_buffer = scsi_result;
-	scmd->request_bufflen = 254;
+	scmd->request_bufflen = 252;
 	scmd->use_sg = 0;
 	scmd->cmd_len = COMMAND_SIZE(scmd->cmnd[0]);
 	scmd->sc_data_direction = SCSI_DATA_READ;