1 /* 2 * Engenio/LSI RDAC SCSI Device Handler 3 * 4 * Copyright (C) 2005 Mike Christie. All rights reserved. 5 * Copyright (C) Chandra Seetharaman, IBM Corp. 2007 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 20 * 21 */ 22 #include <scsi/scsi.h> 23 #include <scsi/scsi_eh.h> 24 #include <scsi/scsi_dh.h> 25 26 #define RDAC_NAME "rdac" 27 28 /* 29 * LSI mode page stuff 30 * 31 * These struct definitions and the forming of the 32 * mode page were taken from the LSI RDAC 2.4 GPL'd 33 * driver, and then converted to Linux conventions. 34 */ 35 #define RDAC_QUIESCENCE_TIME 20; 36 /* 37 * Page Codes 38 */ 39 #define RDAC_PAGE_CODE_REDUNDANT_CONTROLLER 0x2c 40 41 /* 42 * Controller modes definitions 43 */ 44 #define RDAC_MODE_TRANSFER_SPECIFIED_LUNS 0x02 45 46 /* 47 * RDAC Options field 48 */ 49 #define RDAC_FORCED_QUIESENCE 0x02 50 51 #define RDAC_TIMEOUT (60 * HZ) 52 #define RDAC_RETRIES 3 53 54 struct rdac_mode_6_hdr { 55 u8 data_len; 56 u8 medium_type; 57 u8 device_params; 58 u8 block_desc_len; 59 }; 60 61 struct rdac_mode_10_hdr { 62 u16 data_len; 63 u8 medium_type; 64 u8 device_params; 65 u16 reserved; 66 u16 block_desc_len; 67 }; 68 69 struct rdac_mode_common { 70 u8 controller_serial[16]; 71 u8 alt_controller_serial[16]; 72 u8 rdac_mode[2]; 73 u8 alt_rdac_mode[2]; 74 u8 quiescence_timeout; 75 u8 rdac_options; 76 }; 77 78 struct rdac_pg_legacy { 79 struct rdac_mode_6_hdr hdr; 80 u8 page_code; 81 u8 page_len; 82 struct rdac_mode_common common; 83 #define MODE6_MAX_LUN 32 84 u8 lun_table[MODE6_MAX_LUN]; 85 u8 reserved2[32]; 86 u8 reserved3; 87 u8 reserved4; 88 }; 89 90 struct rdac_pg_expanded { 91 struct rdac_mode_10_hdr hdr; 92 u8 page_code; 93 u8 subpage_code; 94 u8 page_len[2]; 95 struct rdac_mode_common common; 96 u8 lun_table[256]; 97 u8 reserved3; 98 u8 reserved4; 99 }; 100 101 struct c9_inquiry { 102 u8 peripheral_info; 103 u8 page_code; /* 0xC9 */ 104 u8 reserved1; 105 u8 page_len; 106 u8 page_id[4]; /* "vace" */ 107 u8 avte_cvp; 108 u8 path_prio; 109 u8 reserved2[38]; 110 }; 111 112 #define SUBSYS_ID_LEN 16 113 #define SLOT_ID_LEN 2 114 115 struct c4_inquiry { 116 u8 peripheral_info; 117 u8 page_code; /* 0xC4 */ 118 u8 reserved1; 119 u8 page_len; 120 u8 page_id[4]; /* "subs" */ 121 u8 subsys_id[SUBSYS_ID_LEN]; 122 u8 revision[4]; 123 u8 slot_id[SLOT_ID_LEN]; 124 u8 reserved[2]; 125 }; 126 127 struct rdac_controller { 128 u8 subsys_id[SUBSYS_ID_LEN]; 129 u8 slot_id[SLOT_ID_LEN]; 130 int use_ms10; 131 struct kref kref; 132 struct list_head node; /* list of all controllers */ 133 union { 134 struct rdac_pg_legacy legacy; 135 struct rdac_pg_expanded expanded; 136 } mode_select; 137 }; 138 struct c8_inquiry { 139 u8 peripheral_info; 140 u8 page_code; /* 0xC8 */ 141 u8 reserved1; 142 u8 page_len; 143 u8 page_id[4]; /* "edid" */ 144 u8 reserved2[3]; 145 u8 vol_uniq_id_len; 146 u8 vol_uniq_id[16]; 147 u8 vol_user_label_len; 148 u8 vol_user_label[60]; 149 u8 array_uniq_id_len; 150 u8 array_unique_id[16]; 151 u8 array_user_label_len; 152 u8 array_user_label[60]; 153 u8 lun[8]; 154 }; 155 156 struct c2_inquiry { 157 u8 peripheral_info; 158 u8 page_code; /* 0xC2 */ 159 u8 reserved1; 160 u8 page_len; 161 u8 page_id[4]; /* "swr4" */ 162 u8 sw_version[3]; 163 u8 sw_date[3]; 164 u8 features_enabled; 165 u8 max_lun_supported; 166 u8 partitions[239]; /* Total allocation length should be 0xFF */ 167 }; 168 169 struct rdac_dh_data { 170 struct rdac_controller *ctlr; 171 #define UNINITIALIZED_LUN (1 << 8) 172 unsigned lun; 173 #define RDAC_STATE_ACTIVE 0 174 #define RDAC_STATE_PASSIVE 1 175 unsigned char state; 176 unsigned char sense[SCSI_SENSE_BUFFERSIZE]; 177 union { 178 struct c2_inquiry c2; 179 struct c4_inquiry c4; 180 struct c8_inquiry c8; 181 struct c9_inquiry c9; 182 } inq; 183 }; 184 185 static LIST_HEAD(ctlr_list); 186 static DEFINE_SPINLOCK(list_lock); 187 188 static inline struct rdac_dh_data *get_rdac_data(struct scsi_device *sdev) 189 { 190 struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; 191 BUG_ON(scsi_dh_data == NULL); 192 return ((struct rdac_dh_data *) scsi_dh_data->buf); 193 } 194 195 static struct request *get_rdac_req(struct scsi_device *sdev, 196 void *buffer, unsigned buflen, int rw) 197 { 198 struct request *rq; 199 struct request_queue *q = sdev->request_queue; 200 struct rdac_dh_data *h = get_rdac_data(sdev); 201 202 rq = blk_get_request(q, rw, GFP_KERNEL); 203 204 if (!rq) { 205 sdev_printk(KERN_INFO, sdev, 206 "get_rdac_req: blk_get_request failed.\n"); 207 return NULL; 208 } 209 210 if (buflen && blk_rq_map_kern(q, rq, buffer, buflen, GFP_KERNEL)) { 211 blk_put_request(rq); 212 sdev_printk(KERN_INFO, sdev, 213 "get_rdac_req: blk_rq_map_kern failed.\n"); 214 return NULL; 215 } 216 217 memset(&rq->cmd, 0, BLK_MAX_CDB); 218 rq->sense = h->sense; 219 memset(rq->sense, 0, SCSI_SENSE_BUFFERSIZE); 220 rq->sense_len = 0; 221 222 rq->cmd_type = REQ_TYPE_BLOCK_PC; 223 rq->cmd_flags |= REQ_FAILFAST | REQ_NOMERGE; 224 rq->retries = RDAC_RETRIES; 225 rq->timeout = RDAC_TIMEOUT; 226 227 return rq; 228 } 229 230 static struct request *rdac_failover_get(struct scsi_device *sdev) 231 { 232 struct request *rq; 233 struct rdac_mode_common *common; 234 unsigned data_size; 235 struct rdac_dh_data *h = get_rdac_data(sdev); 236 237 if (h->ctlr->use_ms10) { 238 struct rdac_pg_expanded *rdac_pg; 239 240 data_size = sizeof(struct rdac_pg_expanded); 241 rdac_pg = &h->ctlr->mode_select.expanded; 242 memset(rdac_pg, 0, data_size); 243 common = &rdac_pg->common; 244 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER + 0x40; 245 rdac_pg->subpage_code = 0x1; 246 rdac_pg->page_len[0] = 0x01; 247 rdac_pg->page_len[1] = 0x28; 248 rdac_pg->lun_table[h->lun] = 0x81; 249 } else { 250 struct rdac_pg_legacy *rdac_pg; 251 252 data_size = sizeof(struct rdac_pg_legacy); 253 rdac_pg = &h->ctlr->mode_select.legacy; 254 memset(rdac_pg, 0, data_size); 255 common = &rdac_pg->common; 256 rdac_pg->page_code = RDAC_PAGE_CODE_REDUNDANT_CONTROLLER; 257 rdac_pg->page_len = 0x68; 258 rdac_pg->lun_table[h->lun] = 0x81; 259 } 260 common->rdac_mode[1] = RDAC_MODE_TRANSFER_SPECIFIED_LUNS; 261 common->quiescence_timeout = RDAC_QUIESCENCE_TIME; 262 common->rdac_options = RDAC_FORCED_QUIESENCE; 263 264 /* get request for block layer packet command */ 265 rq = get_rdac_req(sdev, &h->ctlr->mode_select, data_size, WRITE); 266 if (!rq) 267 return NULL; 268 269 /* Prepare the command. */ 270 if (h->ctlr->use_ms10) { 271 rq->cmd[0] = MODE_SELECT_10; 272 rq->cmd[7] = data_size >> 8; 273 rq->cmd[8] = data_size & 0xff; 274 } else { 275 rq->cmd[0] = MODE_SELECT; 276 rq->cmd[4] = data_size; 277 } 278 rq->cmd_len = COMMAND_SIZE(rq->cmd[0]); 279 280 return rq; 281 } 282 283 static void release_controller(struct kref *kref) 284 { 285 struct rdac_controller *ctlr; 286 ctlr = container_of(kref, struct rdac_controller, kref); 287 288 spin_lock(&list_lock); 289 list_del(&ctlr->node); 290 spin_unlock(&list_lock); 291 kfree(ctlr); 292 } 293 294 static struct rdac_controller *get_controller(u8 *subsys_id, u8 *slot_id) 295 { 296 struct rdac_controller *ctlr, *tmp; 297 298 spin_lock(&list_lock); 299 300 list_for_each_entry(tmp, &ctlr_list, node) { 301 if ((memcmp(tmp->subsys_id, subsys_id, SUBSYS_ID_LEN) == 0) && 302 (memcmp(tmp->slot_id, slot_id, SLOT_ID_LEN) == 0)) { 303 kref_get(&tmp->kref); 304 spin_unlock(&list_lock); 305 return tmp; 306 } 307 } 308 ctlr = kmalloc(sizeof(*ctlr), GFP_ATOMIC); 309 if (!ctlr) 310 goto done; 311 312 /* initialize fields of controller */ 313 memcpy(ctlr->subsys_id, subsys_id, SUBSYS_ID_LEN); 314 memcpy(ctlr->slot_id, slot_id, SLOT_ID_LEN); 315 kref_init(&ctlr->kref); 316 ctlr->use_ms10 = -1; 317 list_add(&ctlr->node, &ctlr_list); 318 done: 319 spin_unlock(&list_lock); 320 return ctlr; 321 } 322 323 static int submit_inquiry(struct scsi_device *sdev, int page_code, 324 unsigned int len) 325 { 326 struct request *rq; 327 struct request_queue *q = sdev->request_queue; 328 struct rdac_dh_data *h = get_rdac_data(sdev); 329 int err = SCSI_DH_RES_TEMP_UNAVAIL; 330 331 rq = get_rdac_req(sdev, &h->inq, len, READ); 332 if (!rq) 333 goto done; 334 335 /* Prepare the command. */ 336 rq->cmd[0] = INQUIRY; 337 rq->cmd[1] = 1; 338 rq->cmd[2] = page_code; 339 rq->cmd[4] = len; 340 rq->cmd_len = COMMAND_SIZE(INQUIRY); 341 err = blk_execute_rq(q, NULL, rq, 1); 342 if (err == -EIO) 343 err = SCSI_DH_IO; 344 done: 345 return err; 346 } 347 348 static int get_lun(struct scsi_device *sdev) 349 { 350 int err; 351 struct c8_inquiry *inqp; 352 struct rdac_dh_data *h = get_rdac_data(sdev); 353 354 err = submit_inquiry(sdev, 0xC8, sizeof(struct c8_inquiry)); 355 if (err == SCSI_DH_OK) { 356 inqp = &h->inq.c8; 357 h->lun = inqp->lun[7]; /* currently it uses only one byte */ 358 } 359 return err; 360 } 361 362 #define RDAC_OWNED 0 363 #define RDAC_UNOWNED 1 364 #define RDAC_FAILED 2 365 static int check_ownership(struct scsi_device *sdev) 366 { 367 int err; 368 struct c9_inquiry *inqp; 369 struct rdac_dh_data *h = get_rdac_data(sdev); 370 371 err = submit_inquiry(sdev, 0xC9, sizeof(struct c9_inquiry)); 372 if (err == SCSI_DH_OK) { 373 err = RDAC_UNOWNED; 374 inqp = &h->inq.c9; 375 /* 376 * If in AVT mode or if the path already owns the LUN, 377 * return RDAC_OWNED; 378 */ 379 if (((inqp->avte_cvp >> 7) == 0x1) || 380 ((inqp->avte_cvp & 0x1) != 0)) 381 err = RDAC_OWNED; 382 } else 383 err = RDAC_FAILED; 384 return err; 385 } 386 387 static int initialize_controller(struct scsi_device *sdev) 388 { 389 int err; 390 struct c4_inquiry *inqp; 391 struct rdac_dh_data *h = get_rdac_data(sdev); 392 393 err = submit_inquiry(sdev, 0xC4, sizeof(struct c4_inquiry)); 394 if (err == SCSI_DH_OK) { 395 inqp = &h->inq.c4; 396 h->ctlr = get_controller(inqp->subsys_id, inqp->slot_id); 397 if (!h->ctlr) 398 err = SCSI_DH_RES_TEMP_UNAVAIL; 399 } 400 return err; 401 } 402 403 static int set_mode_select(struct scsi_device *sdev) 404 { 405 int err; 406 struct c2_inquiry *inqp; 407 struct rdac_dh_data *h = get_rdac_data(sdev); 408 409 err = submit_inquiry(sdev, 0xC2, sizeof(struct c2_inquiry)); 410 if (err == SCSI_DH_OK) { 411 inqp = &h->inq.c2; 412 /* 413 * If more than MODE6_MAX_LUN luns are supported, use 414 * mode select 10 415 */ 416 if (inqp->max_lun_supported >= MODE6_MAX_LUN) 417 h->ctlr->use_ms10 = 1; 418 else 419 h->ctlr->use_ms10 = 0; 420 } 421 return err; 422 } 423 424 static int mode_select_handle_sense(struct scsi_device *sdev) 425 { 426 struct scsi_sense_hdr sense_hdr; 427 struct rdac_dh_data *h = get_rdac_data(sdev); 428 int sense, err = SCSI_DH_IO, ret; 429 430 ret = scsi_normalize_sense(h->sense, SCSI_SENSE_BUFFERSIZE, &sense_hdr); 431 if (!ret) 432 goto done; 433 434 err = SCSI_DH_OK; 435 sense = (sense_hdr.sense_key << 16) | (sense_hdr.asc << 8) | 436 sense_hdr.ascq; 437 /* If it is retryable failure, submit the c9 inquiry again */ 438 if (sense == 0x59136 || sense == 0x68b02 || sense == 0xb8b02 || 439 sense == 0x62900) { 440 /* 0x59136 - Command lock contention 441 * 0x[6b]8b02 - Quiesense in progress or achieved 442 * 0x62900 - Power On, Reset, or Bus Device Reset 443 */ 444 err = SCSI_DH_RETRY; 445 } 446 447 if (sense) 448 sdev_printk(KERN_INFO, sdev, 449 "MODE_SELECT failed with sense 0x%x.\n", sense); 450 done: 451 return err; 452 } 453 454 static int send_mode_select(struct scsi_device *sdev) 455 { 456 struct request *rq; 457 struct request_queue *q = sdev->request_queue; 458 struct rdac_dh_data *h = get_rdac_data(sdev); 459 int err = SCSI_DH_RES_TEMP_UNAVAIL; 460 461 rq = rdac_failover_get(sdev); 462 if (!rq) 463 goto done; 464 465 sdev_printk(KERN_INFO, sdev, "queueing MODE_SELECT command.\n"); 466 467 err = blk_execute_rq(q, NULL, rq, 1); 468 if (err != SCSI_DH_OK) 469 err = mode_select_handle_sense(sdev); 470 if (err == SCSI_DH_OK) 471 h->state = RDAC_STATE_ACTIVE; 472 done: 473 return err; 474 } 475 476 static int rdac_activate(struct scsi_device *sdev) 477 { 478 struct rdac_dh_data *h = get_rdac_data(sdev); 479 int err = SCSI_DH_OK; 480 481 if (h->lun == UNINITIALIZED_LUN) { 482 err = get_lun(sdev); 483 if (err != SCSI_DH_OK) 484 goto done; 485 } 486 487 err = check_ownership(sdev); 488 switch (err) { 489 case RDAC_UNOWNED: 490 break; 491 case RDAC_OWNED: 492 err = SCSI_DH_OK; 493 goto done; 494 case RDAC_FAILED: 495 default: 496 err = SCSI_DH_IO; 497 goto done; 498 } 499 500 if (!h->ctlr) { 501 err = initialize_controller(sdev); 502 if (err != SCSI_DH_OK) 503 goto done; 504 } 505 506 if (h->ctlr->use_ms10 == -1) { 507 err = set_mode_select(sdev); 508 if (err != SCSI_DH_OK) 509 goto done; 510 } 511 512 err = send_mode_select(sdev); 513 done: 514 return err; 515 } 516 517 static int rdac_prep_fn(struct scsi_device *sdev, struct request *req) 518 { 519 struct rdac_dh_data *h = get_rdac_data(sdev); 520 int ret = BLKPREP_OK; 521 522 if (h->state != RDAC_STATE_ACTIVE) { 523 ret = BLKPREP_KILL; 524 req->cmd_flags |= REQ_QUIET; 525 } 526 return ret; 527 528 } 529 530 static int rdac_check_sense(struct scsi_device *sdev, 531 struct scsi_sense_hdr *sense_hdr) 532 { 533 struct rdac_dh_data *h = get_rdac_data(sdev); 534 switch (sense_hdr->sense_key) { 535 case NOT_READY: 536 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x81) 537 /* LUN Not Ready - Storage firmware incompatible 538 * Manual code synchonisation required. 539 * 540 * Nothing we can do here. Try to bypass the path. 541 */ 542 return SUCCESS; 543 if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0xA1) 544 /* LUN Not Ready - Quiescense in progress 545 * 546 * Just retry and wait. 547 */ 548 return NEEDS_RETRY; 549 break; 550 case ILLEGAL_REQUEST: 551 if (sense_hdr->asc == 0x94 && sense_hdr->ascq == 0x01) { 552 /* Invalid Request - Current Logical Unit Ownership. 553 * Controller is not the current owner of the LUN, 554 * Fail the path, so that the other path be used. 555 */ 556 h->state = RDAC_STATE_PASSIVE; 557 return SUCCESS; 558 } 559 break; 560 case UNIT_ATTENTION: 561 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00) 562 /* 563 * Power On, Reset, or Bus Device Reset, just retry. 564 */ 565 return NEEDS_RETRY; 566 break; 567 } 568 /* success just means we do not care what scsi-ml does */ 569 return SCSI_RETURN_NOT_HANDLED; 570 } 571 572 static const struct { 573 char *vendor; 574 char *model; 575 } rdac_dev_list[] = { 576 {"IBM", "1722"}, 577 {"IBM", "1724"}, 578 {"IBM", "1726"}, 579 {"IBM", "1742"}, 580 {"IBM", "1814"}, 581 {"IBM", "1815"}, 582 {"IBM", "1818"}, 583 {"IBM", "3526"}, 584 {"SGI", "TP9400"}, 585 {"SGI", "TP9500"}, 586 {"SGI", "IS"}, 587 {"STK", "OPENstorage D280"}, 588 {"SUN", "CSM200_R"}, 589 {"SUN", "LCSM100_F"}, 590 {NULL, NULL}, 591 }; 592 593 static int rdac_bus_notify(struct notifier_block *, unsigned long, void *); 594 595 static struct scsi_device_handler rdac_dh = { 596 .name = RDAC_NAME, 597 .module = THIS_MODULE, 598 .nb.notifier_call = rdac_bus_notify, 599 .prep_fn = rdac_prep_fn, 600 .check_sense = rdac_check_sense, 601 .activate = rdac_activate, 602 }; 603 604 /* 605 * TODO: need some interface so we can set trespass values 606 */ 607 static int rdac_bus_notify(struct notifier_block *nb, 608 unsigned long action, void *data) 609 { 610 struct device *dev = data; 611 struct scsi_device *sdev; 612 struct scsi_dh_data *scsi_dh_data; 613 struct rdac_dh_data *h; 614 int i, found = 0; 615 unsigned long flags; 616 617 if (!scsi_is_sdev_device(dev)) 618 return 0; 619 620 sdev = to_scsi_device(dev); 621 622 if (action == BUS_NOTIFY_ADD_DEVICE) { 623 for (i = 0; rdac_dev_list[i].vendor; i++) { 624 if (!strncmp(sdev->vendor, rdac_dev_list[i].vendor, 625 strlen(rdac_dev_list[i].vendor)) && 626 !strncmp(sdev->model, rdac_dev_list[i].model, 627 strlen(rdac_dev_list[i].model))) { 628 found = 1; 629 break; 630 } 631 } 632 if (!found) 633 goto out; 634 635 scsi_dh_data = kzalloc(sizeof(struct scsi_device_handler *) 636 + sizeof(*h) , GFP_KERNEL); 637 if (!scsi_dh_data) { 638 sdev_printk(KERN_ERR, sdev, "Attach failed %s.\n", 639 RDAC_NAME); 640 goto out; 641 } 642 643 scsi_dh_data->scsi_dh = &rdac_dh; 644 h = (struct rdac_dh_data *) scsi_dh_data->buf; 645 h->lun = UNINITIALIZED_LUN; 646 h->state = RDAC_STATE_ACTIVE; 647 spin_lock_irqsave(sdev->request_queue->queue_lock, flags); 648 sdev->scsi_dh_data = scsi_dh_data; 649 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 650 try_module_get(THIS_MODULE); 651 652 sdev_printk(KERN_NOTICE, sdev, "Attached %s.\n", RDAC_NAME); 653 654 } else if (action == BUS_NOTIFY_DEL_DEVICE) { 655 if (sdev->scsi_dh_data == NULL || 656 sdev->scsi_dh_data->scsi_dh != &rdac_dh) 657 goto out; 658 659 spin_lock_irqsave(sdev->request_queue->queue_lock, flags); 660 scsi_dh_data = sdev->scsi_dh_data; 661 sdev->scsi_dh_data = NULL; 662 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags); 663 664 h = (struct rdac_dh_data *) scsi_dh_data->buf; 665 if (h->ctlr) 666 kref_put(&h->ctlr->kref, release_controller); 667 kfree(scsi_dh_data); 668 module_put(THIS_MODULE); 669 sdev_printk(KERN_NOTICE, sdev, "Dettached %s.\n", RDAC_NAME); 670 } 671 672 out: 673 return 0; 674 } 675 676 static int __init rdac_init(void) 677 { 678 int r; 679 680 r = scsi_register_device_handler(&rdac_dh); 681 if (r != 0) 682 printk(KERN_ERR "Failed to register scsi device handler."); 683 return r; 684 } 685 686 static void __exit rdac_exit(void) 687 { 688 scsi_unregister_device_handler(&rdac_dh); 689 } 690 691 module_init(rdac_init); 692 module_exit(rdac_exit); 693 694 MODULE_DESCRIPTION("Multipath LSI/Engenio RDAC driver"); 695 MODULE_AUTHOR("Mike Christie, Chandra Seetharaman"); 696 MODULE_LICENSE("GPL"); 697