Free Electrons

Embedded Linux Experts

   1
   2
   3
   4
   5
   6
   7
   8
   9
  10
  11
  12
  13
  14
  15
  16
  17
  18
  19
  20
  21
  22
  23
  24
  25
  26
  27
  28
  29
  30
  31
  32
  33
  34
  35
  36
  37
  38
  39
  40
  41
  42
  43
  44
  45
  46
  47
  48
  49
  50
  51
  52
  53
  54
  55
  56
  57
  58
  59
  60
  61
  62
  63
  64
  65
  66
  67
  68
  69
  70
  71
  72
  73
  74
  75
  76
  77
  78
  79
  80
  81
  82
  83
  84
  85
  86
  87
  88
  89
  90
  91
  92
  93
  94
  95
  96
  97
  98
  99
 100
 101
 102
 103
 104
 105
 106
 107
 108
 109
 110
 111
 112
 113
 114
 115
 116
 117
 118
 119
 120
 121
 122
 123
 124
 125
 126
 127
 128
 129
 130
 131
 132
 133
 134
 135
 136
 137
 138
 139
 140
 141
 142
 143
 144
 145
 146
 147
 148
 149
 150
 151
 152
 153
 154
 155
 156
 157
 158
 159
 160
 161
 162
 163
 164
 165
 166
 167
 168
 169
 170
 171
 172
 173
 174
 175
 176
 177
 178
 179
 180
 181
 182
 183
 184
 185
 186
 187
 188
 189
 190
 191
 192
 193
 194
 195
 196
 197
 198
 199
 200
 201
 202
 203
 204
 205
 206
 207
 208
 209
 210
 211
 212
 213
 214
 215
 216
 217
 218
 219
 220
 221
 222
 223
 224
 225
 226
 227
 228
 229
 230
 231
 232
 233
 234
 235
 236
 237
 238
 239
 240
 241
 242
 243
 244
 245
 246
 247
 248
 249
 250
 251
 252
 253
 254
 255
 256
 257
 258
 259
 260
 261
 262
 263
 264
 265
 266
 267
 268
 269
 270
 271
 272
 273
 274
 275
 276
 277
 278
 279
 280
 281
 282
 283
 284
 285
 286
 287
 288
 289
 290
 291
 292
 293
 294
 295
 296
 297
 298
 299
 300
 301
 302
 303
 304
 305
 306
 307
 308
 309
 310
 311
 312
 313
 314
 315
 316
 317
 318
 319
 320
 321
 322
 323
 324
 325
 326
 327
 328
 329
 330
 331
 332
 333
 334
 335
 336
 337
 338
 339
 340
 341
 342
 343
 344
 345
 346
 347
 348
 349
 350
 351
 352
 353
 354
 355
 356
 357
 358
 359
 360
 361
 362
 363
 364
 365
 366
 367
 368
 369
 370
 371
 372
 373
 374
 375
 376
 377
 378
 379
 380
 381
 382
 383
 384
 385
 386
 387
 388
 389
 390
 391
 392
 393
 394
 395
 396
 397
 398
 399
 400
 401
 402
 403
 404
 405
 406
 407
 408
 409
 410
 411
 412
 413
 414
 415
 416
 417
 418
 419
 420
 421
 422
 423
 424
 425
 426
 427
 428
 429
 430
 431
 432
 433
 434
 435
 436
 437
 438
 439
 440
 441
 442
 443
 444
 445
 446
 447
 448
 449
 450
 451
 452
 453
 454
 455
 456
 457
 458
 459
 460
 461
 462
 463
 464
 465
 466
 467
 468
 469
 470
 471
 472
 473
 474
 475
 476
 477
 478
 479
 480
 481
 482
 483
 484
 485
 486
 487
 488
 489
 490
 491
 492
 493
 494
 495
 496
 497
 498
 499
 500
 501
 502
 503
 504
 505
 506
 507
 508
 509
 510
 511
 512
 513
 514
 515
 516
 517
 518
 519
 520
 521
 522
 523
 524
 525
 526
 527
 528
 529
 530
 531
 532
 533
 534
 535
 536
 537
 538
 539
 540
 541
 542
 543
 544
 545
 546
 547
 548
 549
 550
 551
 552
 553
 554
 555
 556
 557
 558
 559
 560
 561
 562
 563
 564
 565
 566
 567
 568
 569
 570
 571
 572
 573
 574
 575
 576
 577
 578
 579
 580
 581
 582
 583
 584
 585
 586
 587
 588
 589
 590
 591
 592
 593
 594
 595
 596
 597
 598
 599
 600
 601
 602
 603
 604
 605
 606
 607
 608
 609
 610
 611
 612
 613
 614
 615
 616
 617
 618
 619
 620
 621
 622
 623
 624
 625
 626
 627
 628
 629
 630
 631
 632
 633
 634
 635
 636
 637
 638
 639
 640
 641
 642
 643
 644
 645
 646
 647
 648
 649
 650
 651
 652
 653
 654
 655
 656
 657
 658
 659
 660
 661
 662
 663
 664
 665
 666
 667
 668
 669
 670
 671
 672
 673
 674
 675
 676
 677
 678
 679
 680
 681
 682
 683
 684
 685
 686
 687
 688
 689
 690
 691
 692
 693
 694
 695
 696
 697
 698
 699
 700
 701
 702
 703
 704
 705
 706
 707
 708
 709
 710
 711
 712
 713
 714
 715
 716
 717
 718
 719
 720
 721
 722
 723
 724
 725
 726
 727
 728
 729
 730
 731
 732
 733
 734
 735
 736
 737
 738
 739
 740
 741
 742
 743
 744
 745
 746
 747
 748
 749
 750
 751
 752
 753
 754
 755
 756
 757
 758
 759
 760
 761
 762
 763
 764
 765
 766
 767
 768
 769
 770
 771
 772
 773
 774
 775
 776
 777
 778
 779
 780
 781
 782
 783
 784
 785
 786
 787
 788
 789
 790
 791
 792
 793
 794
 795
 796
 797
 798
 799
 800
 801
 802
 803
 804
 805
 806
 807
 808
 809
 810
 811
 812
 813
 814
 815
 816
 817
 818
 819
 820
 821
 822
 823
 824
 825
 826
 827
 828
 829
 830
 831
 832
 833
 834
 835
 836
 837
 838
 839
 840
 841
 842
 843
 844
 845
 846
 847
 848
 849
 850
 851
 852
 853
 854
 855
 856
 857
 858
 859
 860
 861
 862
 863
 864
 865
 866
 867
 868
 869
 870
 871
 872
 873
 874
 875
 876
 877
 878
 879
 880
 881
 882
 883
 884
 885
 886
 887
 888
 889
 890
 891
 892
 893
 894
 895
 896
 897
 898
 899
 900
 901
 902
 903
 904
 905
 906
 907
 908
 909
 910
 911
 912
 913
 914
 915
 916
 917
 918
 919
 920
 921
 922
 923
 924
 925
 926
 927
 928
 929
 930
 931
 932
 933
 934
 935
 936
 937
 938
 939
 940
 941
 942
 943
 944
 945
 946
 947
 948
 949
 950
 951
 952
 953
 954
 955
 956
 957
 958
 959
 960
 961
 962
 963
 964
 965
 966
 967
 968
 969
 970
 971
 972
 973
 974
 975
 976
 977
 978
 979
 980
 981
 982
 983
 984
 985
 986
 987
 988
 989
 990
 991
 992
 993
 994
 995
 996
 997
 998
 999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
/*
 * Linux Ethernet device driver for the 3Com Etherlink Plus (3C505)
 *      By Craig Southeren, Juha Laiho and Philip Blundell
 *
 * 3c505.c      This module implements an interface to the 3Com
 *              Etherlink Plus (3c505) Ethernet card. Linux device
 *              driver interface reverse engineered from the Linux 3C509
 *              device drivers. Some 3C505 information gleaned from
 *              the Crynwr packet driver. Still this driver would not
 *              be here without 3C505 technical reference provided by
 *              3Com.
 *
 * $Id: 3c505.c,v 1.10 1996/04/16 13:06:27 phil Exp $
 *
 * Authors:     Linux 3c505 device driver by
 *                      Craig Southeren, <craigs@ineluki.apana.org.au>
 *              Final debugging by
 *                      Andrew Tridgell, <tridge@nimbus.anu.edu.au>
 *              Auto irq/address, tuning, cleanup and v1.1.4+ kernel mods by
 *                      Juha Laiho, <jlaiho@ichaos.nullnet.fi>
 *              Linux 3C509 driver by
 *                      Donald Becker, <becker@super.org>
 *			(Now at <becker@scyld.com>)
 *              Crynwr packet driver by
 *                      Krishnan Gopalan and Gregg Stefancik,
 *                      Clemson University Engineering Computer Operations.
 *                      Portions of the code have been adapted from the 3c505
 *                         driver for NCSA Telnet by Bruce Orchard and later
 *                         modified by Warren Van Houten and krus@diku.dk.
 *              3C505 technical information provided by
 *                      Terry Murphy, of 3Com Network Adapter Division
 *              Linux 1.3.0 changes by
 *                      Alan Cox <Alan.Cox@linux.org>
 *              More debugging, DMA support, currently maintained by
 *                      Philip Blundell <philb@gnu.org>
 *              Multicard/soft configurable dma channel/rev 2 hardware support
 *                      by Christopher Collins <ccollins@pcug.org.au>
 *		Ethtool support (jgarzik), 11/17/2001
 */

#define DRV_NAME	"3c505"
#define DRV_VERSION	"1.10a"


/* Theory of operation:
 *
 * The 3c505 is quite an intelligent board.  All communication with it is done
 * by means of Primary Command Blocks (PCBs); these are transferred using PIO
 * through the command register.  The card has 256k of on-board RAM, which is
 * used to buffer received packets.  It might seem at first that more buffers
 * are better, but in fact this isn't true.  From my tests, it seems that
 * more than about 10 buffers are unnecessary, and there is a noticeable
 * performance hit in having more active on the card.  So the majority of the
 * card's memory isn't, in fact, used.  Sadly, the card only has one transmit
 * buffer and, short of loading our own firmware into it (which is what some
 * drivers resort to) there's nothing we can do about this.
 *
 * We keep up to 4 "receive packet" commands active on the board at a time.
 * When a packet comes in, so long as there is a receive command active, the
 * board will send us a "packet received" PCB and then add the data for that
 * packet to the DMA queue.  If a DMA transfer is not already in progress, we
 * set one up to start uploading the data.  We have to maintain a list of
 * backlogged receive packets, because the card may decide to tell us about
 * a newly-arrived packet at any time, and we may not be able to start a DMA
 * transfer immediately (ie one may already be going on).  We can't NAK the
 * PCB, because then it would throw the packet away.
 *
 * Trying to send a PCB to the card at the wrong moment seems to have bad
 * effects.  If we send it a transmit PCB while a receive DMA is happening,
 * it will just NAK the PCB and so we will have wasted our time.  Worse, it
 * sometimes seems to interrupt the transfer.  The majority of the low-level
 * code is protected by one huge semaphore -- "busy" -- which is set whenever
 * it probably isn't safe to do anything to the card.  The receive routine
 * must gain a lock on "busy" before it can start a DMA transfer, and the
 * transmit routine must gain a lock before it sends the first PCB to the card.
 * The send_pcb() routine also has an internal semaphore to protect it against
 * being re-entered (which would be disastrous) -- this is needed because
 * several things can happen asynchronously (re-priming the receiver and
 * asking the card for statistics, for example).  send_pcb() will also refuse
 * to talk to the card at all if a DMA upload is happening.  The higher-level
 * networking code will reschedule a later retry if some part of the driver
 * is blocked.  In practice, this doesn't seem to happen very often.
 */

/* This driver may now work with revision 2.x hardware, since all the read
 * operations on the HCR have been removed (we now keep our own softcopy).
 * But I don't have an old card to test it on.
 *
 * This has had the bad effect that the autoprobe routine is now a bit
 * less friendly to other devices.  However, it was never very good.
 * before, so I doubt it will hurt anybody.
 */

/* The driver is a mess.  I took Craig's and Juha's code, and hacked it firstly
 * to make it more reliable, and secondly to add DMA mode.  Many things could
 * probably be done better; the concurrency protection is particularly awful.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/spinlock.h>
#include <linux/ethtool.h>
#include <linux/delay.h>
#include <linux/bitops.h>

#include <asm/uaccess.h>
#include <asm/io.h>
#include <asm/dma.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/init.h>

#include "3c505.h"

/*********************************************************
 *
 *  define debug messages here as common strings to reduce space
 *
 *********************************************************/

static const char filename[] = __FILE__;

static const char timeout_msg[] = "*** timeout at %s:%s (line %d) ***\n";
#define TIMEOUT_MSG(lineno) \
	printk(timeout_msg, filename,__FUNCTION__,(lineno))

static const char invalid_pcb_msg[] =
"*** invalid pcb length %d at %s:%s (line %d) ***\n";
#define INVALID_PCB_MSG(len) \
	printk(invalid_pcb_msg, (len),filename,__FUNCTION__,__LINE__)

static char search_msg[] __initdata = KERN_INFO "%s: Looking for 3c505 adapter at address %#x...";

static char stilllooking_msg[] __initdata = "still looking...";

static char found_msg[] __initdata = "found.\n";

static char notfound_msg[] __initdata = "not found (reason = %d)\n";

static char couldnot_msg[] __initdata = KERN_INFO "%s: 3c505 not found\n";

/*********************************************************
 *
 *  various other debug stuff
 *
 *********************************************************/

#ifdef ELP_DEBUG
static int elp_debug = ELP_DEBUG;
#else
static int elp_debug;
#endif
#define debug elp_debug

/*
 *  0 = no messages (well, some)
 *  1 = messages when high level commands performed
 *  2 = messages when low level commands performed
 *  3 = messages when interrupts received
 */

/*****************************************************************
 *
 * useful macros
 *
 *****************************************************************/

#ifndef	TRUE
#define	TRUE	1
#endif

#ifndef	FALSE
#define	FALSE	0
#endif


/*****************************************************************
 *
 * List of I/O-addresses we try to auto-sense
 * Last element MUST BE 0!
 *****************************************************************/

static int addr_list[] __initdata = {0x300, 0x280, 0x310, 0};

/* Dma Memory related stuff */

static unsigned long dma_mem_alloc(int size)
{
	int order = get_order(size);
	return __get_dma_pages(GFP_KERNEL, order);
}


/*****************************************************************
 *
 * Functions for I/O (note the inline !)
 *
 *****************************************************************/

static inline unsigned char inb_status(unsigned int base_addr)
{
	return inb(base_addr + PORT_STATUS);
}

static inline int inb_command(unsigned int base_addr)
{
	return inb(base_addr + PORT_COMMAND);
}

static inline void outb_control(unsigned char val, struct net_device *dev)
{
	outb(val, dev->base_addr + PORT_CONTROL);
	((elp_device *)(dev->priv))->hcr_val = val;
}

#define HCR_VAL(x)   (((elp_device *)((x)->priv))->hcr_val)

static inline void outb_command(unsigned char val, unsigned int base_addr)
{
	outb(val, base_addr + PORT_COMMAND);
}

static inline unsigned int backlog_next(unsigned int n)
{
	return (n + 1) % BACKLOG_SIZE;
}

/*****************************************************************
 *
 *  useful functions for accessing the adapter
 *
 *****************************************************************/

/*
 * use this routine when accessing the ASF bits as they are
 * changed asynchronously by the adapter
 */

/* get adapter PCB status */
#define	GET_ASF(addr) \
	(get_status(addr)&ASF_PCB_MASK)

static inline int get_status(unsigned int base_addr)
{
	unsigned long timeout = jiffies + 10*HZ/100;
	register int stat1;
	do {
		stat1 = inb_status(base_addr);
	} while (stat1 != inb_status(base_addr) && time_before(jiffies, timeout));
	if (time_after_eq(jiffies, timeout))
		TIMEOUT_MSG(__LINE__);
	return stat1;
}

static inline void set_hsf(struct net_device *dev, int hsf)
{
	elp_device *adapter = dev->priv;
	unsigned long flags;

	spin_lock_irqsave(&adapter->lock, flags);
	outb_control((HCR_VAL(dev) & ~HSF_PCB_MASK) | hsf, dev);
	spin_unlock_irqrestore(&adapter->lock, flags);
}

static int start_receive(struct net_device *, pcb_struct *);

static inline void adapter_reset(struct net_device *dev)
{
	unsigned long timeout;
	elp_device *adapter = dev->priv;
	unsigned char orig_hcr = adapter->hcr_val;

	outb_control(0, dev);

	if (inb_status(dev->base_addr) & ACRF) {
		do {
			inb_command(dev->base_addr);
			timeout = jiffies + 2*HZ/100;
			while (time_before_eq(jiffies, timeout) && !(inb_status(dev->base_addr) & ACRF));
		} while (inb_status(dev->base_addr) & ACRF);
		set_hsf(dev, HSF_PCB_NAK);
	}
	outb_control(adapter->hcr_val | ATTN | DIR, dev);
	mdelay(10);
	outb_control(adapter->hcr_val & ~ATTN, dev);
	mdelay(10);
	outb_control(adapter->hcr_val | FLSH, dev);
	mdelay(10);
	outb_control(adapter->hcr_val & ~FLSH, dev);
	mdelay(10);

	outb_control(orig_hcr, dev);
	if (!start_receive(dev, &adapter->tx_pcb))
		printk(KERN_ERR "%s: start receive command failed \n", dev->name);
}

/* Check to make sure that a DMA transfer hasn't timed out.  This should
 * never happen in theory, but seems to occur occasionally if the card gets
 * prodded at the wrong time.
 */
static inline void check_3c505_dma(struct net_device *dev)
{
	elp_device *adapter = dev->priv;
	if (adapter->dmaing && time_after(jiffies, adapter->current_dma.start_time + 10)) {
		unsigned long flags, f;
		printk(KERN_ERR "%s: DMA %s timed out, %d bytes left\n", dev->name, adapter->current_dma.direction ? "download" : "upload", get_dma_residue(dev->dma));
		spin_lock_irqsave(&adapter->lock, flags);
		adapter->dmaing = 0;
		adapter->busy = 0;
		
		f=claim_dma_lock();
		disable_dma(dev->dma);
		release_dma_lock(f);
		
		if (adapter->rx_active)
			adapter->rx_active--;
		outb_control(adapter->hcr_val & ~(DMAE | TCEN | DIR), dev);
		spin_unlock_irqrestore(&adapter->lock, flags);
	}
}

/* Primitive functions used by send_pcb() */
static inline unsigned int send_pcb_slow(unsigned int base_addr, unsigned char byte)
{
	unsigned long timeout;
	outb_command(byte, base_addr);
	for (timeout = jiffies + 5*HZ/100; time_before(jiffies, timeout);) {
		if (inb_status(base_addr) & HCRE)
			return FALSE;
	}
	printk(KERN_WARNING "3c505: send_pcb_slow timed out\n");
	return TRUE;
}

static inline unsigned int send_pcb_fast(unsigned int base_addr, unsigned char byte)
{
	unsigned int timeout;
	outb_command(byte, base_addr);
	for (timeout = 0; timeout < 40000; timeout++) {
		if (inb_status(base_addr) & HCRE)
			return FALSE;
	}
	printk(KERN_WARNING "3c505: send_pcb_fast timed out\n");
	return TRUE;
}

/* Check to see if the receiver needs restarting, and kick it if so */
static inline void prime_rx(struct net_device *dev)
{
	elp_device *adapter = dev->priv;
	while (adapter->rx_active < ELP_RX_PCBS && netif_running(dev)) {
		if (!start_receive(dev, &adapter->itx_pcb))
			break;
	}
}

/*****************************************************************
 *
 * send_pcb
 *   Send a PCB to the adapter.
 *
 *	output byte to command reg  --<--+
 *	wait until HCRE is non zero      |
 *	loop until all bytes sent   -->--+
 *	set HSF1 and HSF2 to 1
 *	output pcb length
 *	wait until ASF give ACK or NAK
 *	set HSF1 and HSF2 to 0
 *
 *****************************************************************/

/* This can be quite slow -- the adapter is allowed to take up to 40ms
 * to respond to the initial interrupt.
 *
 * We run initially with interrupts turned on, but with a semaphore set
 * so that nobody tries to re-enter this code.  Once the first byte has
 * gone through, we turn interrupts off and then send the others (the
 * timeout is reduced to 500us).
 */

static int send_pcb(struct net_device *dev, pcb_struct * pcb)
{
	int i;
	unsigned long timeout;
	elp_device *adapter = dev->priv;
	unsigned long flags;

	check_3c505_dma(dev);

	if (adapter->dmaing && adapter->current_dma.direction == 0)
		return FALSE;

	/* Avoid contention */
	if (test_and_set_bit(1, &adapter->send_pcb_semaphore)) {
		if (elp_debug >= 3) {
			printk(KERN_DEBUG "%s: send_pcb entered while threaded\n", dev->name);
		}
		return FALSE;
	}
	/*
	 * load each byte into the command register and
	 * wait for the HCRE bit to indicate the adapter
	 * had read the byte
	 */
	set_hsf(dev, 0);

	if (send_pcb_slow(dev->base_addr, pcb->command))
		goto abort;

	spin_lock_irqsave(&adapter->lock, flags);

	if (send_pcb_fast(dev->base_addr, pcb->length))
		goto sti_abort;

	for (i = 0; i < pcb->length; i++) {
		if (send_pcb_fast(dev->base_addr, pcb->data.raw[i]))
			goto sti_abort;
	}

	outb_control(adapter->hcr_val | 3, dev);	/* signal end of PCB */
	outb_command(2 + pcb->length, dev->base_addr);

	/* now wait for the acknowledgement */
	spin_unlock_irqrestore(&adapter->lock, flags);

	for (timeout = jiffies + 5*HZ/100; time_before(jiffies, timeout);) {
		switch (GET_ASF(dev->base_addr)) {
		case ASF_PCB_ACK:
			adapter->send_pcb_semaphore = 0;
			return TRUE;

		case ASF_PCB_NAK:
#ifdef ELP_DEBUG
			printk(KERN_DEBUG "%s: send_pcb got NAK\n", dev->name);
#endif
			goto abort;
		}
	}

	if (elp_debug >= 1)
		printk(KERN_DEBUG "%s: timeout waiting for PCB acknowledge (status %02x)\n", dev->name, inb_status(dev->base_addr));
	goto abort;

      sti_abort:
	spin_unlock_irqrestore(&adapter->lock, flags);
      abort:
	adapter->send_pcb_semaphore = 0;
	return FALSE;
}


/*****************************************************************
 *
 * receive_pcb
 *   Read a PCB from the adapter
 *
 *	wait for ACRF to be non-zero        ---<---+
 *	input a byte                               |
 *	if ASF1 and ASF2 were not both one         |
 *		before byte was read, loop      --->---+
 *	set HSF1 and HSF2 for ack
 *
 *****************************************************************/

static int receive_pcb(struct net_device *dev, pcb_struct * pcb)
{
	int i, j;
	int total_length;
	int stat;
	unsigned long timeout;
	unsigned long flags;

	elp_device *adapter = dev->priv;

	set_hsf(dev, 0);

	/* get the command code */
	timeout = jiffies + 2*HZ/100;
	while (((stat = get_status(dev->base_addr)) & ACRF) == 0 && time_before(jiffies, timeout));
	if (time_after_eq(jiffies, timeout)) {
		TIMEOUT_MSG(__LINE__);
		return FALSE;
	}
	pcb->command = inb_command(dev->base_addr);

	/* read the data length */
	timeout = jiffies + 3*HZ/100;
	while (((stat = get_status(dev->base_addr)) & ACRF) == 0 && time_before(jiffies, timeout));
	if (time_after_eq(jiffies, timeout)) {
		TIMEOUT_MSG(__LINE__);
		printk(KERN_INFO "%s: status %02x\n", dev->name, stat);
		return FALSE;
	}
	pcb->length = inb_command(dev->base_addr);

	if (pcb->length > MAX_PCB_DATA) {
		INVALID_PCB_MSG(pcb->length);
		adapter_reset(dev);
		return FALSE;
	}
	/* read the data */
	spin_lock_irqsave(&adapter->lock, flags);
	i = 0;
	do {
		j = 0;
		while (((stat = get_status(dev->base_addr)) & ACRF) == 0 && j++ < 20000);
		pcb->data.raw[i++] = inb_command(dev->base_addr);
		if (i > MAX_PCB_DATA)
			INVALID_PCB_MSG(i);
	} while ((stat & ASF_PCB_MASK) != ASF_PCB_END && j < 20000);
	spin_unlock_irqrestore(&adapter->lock, flags);
	if (j >= 20000) {
		TIMEOUT_MSG(__LINE__);
		return FALSE;
	}
	/* woops, the last "data" byte was really the length! */
	total_length = pcb->data.raw[--i];

	/* safety check total length vs data length */
	if (total_length != (pcb->length + 2)) {
		if (elp_debug >= 2)
			printk(KERN_WARNING "%s: mangled PCB received\n", dev->name);
		set_hsf(dev, HSF_PCB_NAK);
		return FALSE;
	}

	if (pcb->command == CMD_RECEIVE_PACKET_COMPLETE) {
		if (test_and_set_bit(0, (void *) &adapter->busy)) {
			if (backlog_next(adapter->rx_backlog.in) == adapter->rx_backlog.out) {
				set_hsf(dev, HSF_PCB_NAK);
				printk(KERN_WARNING "%s: PCB rejected, transfer in progress and backlog full\n", dev->name);
				pcb->command = 0;
				return TRUE;
			} else {
				pcb->command = 0xff;
			}
		}
	}
	set_hsf(dev, HSF_PCB_ACK);
	return TRUE;
}

/******************************************************
 *
 *  queue a receive command on the adapter so we will get an
 *  interrupt when a packet is received.
 *
 ******************************************************/

static int start_receive(struct net_device *dev, pcb_struct * tx_pcb)
{
	int status;
	elp_device *adapter = dev->priv;

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: restarting receiver\n", dev->name);
	tx_pcb->command = CMD_RECEIVE_PACKET;
	tx_pcb->length = sizeof(struct Rcv_pkt);
	tx_pcb->data.rcv_pkt.buf_seg
	    = tx_pcb->data.rcv_pkt.buf_ofs = 0;		/* Unused */
	tx_pcb->data.rcv_pkt.buf_len = 1600;
	tx_pcb->data.rcv_pkt.timeout = 0;	/* set timeout to zero */
	status = send_pcb(dev, tx_pcb);
	if (status)
		adapter->rx_active++;
	return status;
}

/******************************************************
 *
 * extract a packet from the adapter
 * this routine is only called from within the interrupt
 * service routine, so no cli/sti calls are needed
 * note that the length is always assumed to be even
 *
 ******************************************************/

static void receive_packet(struct net_device *dev, int len)
{
	int rlen;
	elp_device *adapter = dev->priv;
	void *target;
	struct sk_buff *skb;
	unsigned long flags;

	rlen = (len + 1) & ~1;
	skb = dev_alloc_skb(rlen + 2);

	if (!skb) {
		printk(KERN_WARNING "%s: memory squeeze, dropping packet\n", dev->name);
		target = adapter->dma_buffer;
		adapter->current_dma.target = NULL;
		/* FIXME: stats */
		return;
	}

	skb_reserve(skb, 2);
	target = skb_put(skb, rlen);
	if ((unsigned long)(target + rlen) >= MAX_DMA_ADDRESS) {
		adapter->current_dma.target = target;
		target = adapter->dma_buffer;
	} else {
		adapter->current_dma.target = NULL;
	}

	/* if this happens, we die */
	if (test_and_set_bit(0, (void *) &adapter->dmaing))
		printk(KERN_ERR "%s: rx blocked, DMA in progress, dir %d\n", dev->name, adapter->current_dma.direction);

	skb->dev = dev;
	adapter->current_dma.direction = 0;
	adapter->current_dma.length = rlen;
	adapter->current_dma.skb = skb;
	adapter->current_dma.start_time = jiffies;

	outb_control(adapter->hcr_val | DIR | TCEN | DMAE, dev);

	flags=claim_dma_lock();
	disable_dma(dev->dma);
	clear_dma_ff(dev->dma);
	set_dma_mode(dev->dma, 0x04);	/* dma read */
	set_dma_addr(dev->dma, isa_virt_to_bus(target));
	set_dma_count(dev->dma, rlen);
	enable_dma(dev->dma);
	release_dma_lock(flags);

	if (elp_debug >= 3) {
		printk(KERN_DEBUG "%s: rx DMA transfer started\n", dev->name);
	}

	if (adapter->rx_active)
		adapter->rx_active--;

	if (!adapter->busy)
		printk(KERN_WARNING "%s: receive_packet called, busy not set.\n", dev->name);
}

/******************************************************
 *
 * interrupt handler
 *
 ******************************************************/

static irqreturn_t elp_interrupt(int irq, void *dev_id, struct pt_regs *reg_ptr)
{
	int len;
	int dlen;
	int icount = 0;
	struct net_device *dev;
	elp_device *adapter;
	unsigned long timeout;

	dev = dev_id;
	adapter = (elp_device *) dev->priv;
	
	spin_lock(&adapter->lock);

	do {
		/*
		 * has a DMA transfer finished?
		 */
		if (inb_status(dev->base_addr) & DONE) {
			if (!adapter->dmaing) {
				printk(KERN_WARNING "%s: phantom DMA completed\n", dev->name);
			}
			if (elp_debug >= 3) {
				printk(KERN_DEBUG "%s: %s DMA complete, status %02x\n", dev->name, adapter->current_dma.direction ? "tx" : "rx", inb_status(dev->base_addr));
			}

			outb_control(adapter->hcr_val & ~(DMAE | TCEN | DIR), dev);
			if (adapter->current_dma.direction) {
				dev_kfree_skb_irq(adapter->current_dma.skb);
			} else {
				struct sk_buff *skb = adapter->current_dma.skb;
				if (skb) {
					if (adapter->current_dma.target) {
				  	/* have already done the skb_put() */
				  	memcpy(adapter->current_dma.target, adapter->dma_buffer, adapter->current_dma.length);
					}
					skb->protocol = eth_type_trans(skb,dev);
					adapter->stats.rx_bytes += skb->len;
					netif_rx(skb);
					dev->last_rx = jiffies;
				}
			}
			adapter->dmaing = 0;
			if (adapter->rx_backlog.in != adapter->rx_backlog.out) {
				int t = adapter->rx_backlog.length[adapter->rx_backlog.out];
				adapter->rx_backlog.out = backlog_next(adapter->rx_backlog.out);
				if (elp_debug >= 2)
					printk(KERN_DEBUG "%s: receiving backlogged packet (%d)\n", dev->name, t);
				receive_packet(dev, t);
			} else {
				adapter->busy = 0;
			}
		} else {
			/* has one timed out? */
			check_3c505_dma(dev);
		}

		/*
		 * receive a PCB from the adapter
		 */
		timeout = jiffies + 3*HZ/100;
		while ((inb_status(dev->base_addr) & ACRF) != 0 && time_before(jiffies, timeout)) {
			if (receive_pcb(dev, &adapter->irx_pcb)) {
				switch (adapter->irx_pcb.command) 
				{
				case 0:
					break;
					/*
					 * received a packet - this must be handled fast
					 */
				case 0xff:
				case CMD_RECEIVE_PACKET_COMPLETE:
					/* if the device isn't open, don't pass packets up the stack */
					if (!netif_running(dev))
						break;
					len = adapter->irx_pcb.data.rcv_resp.pkt_len;
					dlen = adapter->irx_pcb.data.rcv_resp.buf_len;
					if (adapter->irx_pcb.data.rcv_resp.timeout != 0) {
						printk(KERN_ERR "%s: interrupt - packet not received correctly\n", dev->name);
					} else {
						if (elp_debug >= 3) {
							printk(KERN_DEBUG "%s: interrupt - packet received of length %i (%i)\n", dev->name, len, dlen);
						}
						if (adapter->irx_pcb.command == 0xff) {
							if (elp_debug >= 2)
								printk(KERN_DEBUG "%s: adding packet to backlog (len = %d)\n", dev->name, dlen);
							adapter->rx_backlog.length[adapter->rx_backlog.in] = dlen;
							adapter->rx_backlog.in = backlog_next(adapter->rx_backlog.in);
						} else {
							receive_packet(dev, dlen);
						}
						if (elp_debug >= 3)
							printk(KERN_DEBUG "%s: packet received\n", dev->name);
					}
					break;

					/*
					 * 82586 configured correctly
					 */
				case CMD_CONFIGURE_82586_RESPONSE:
					adapter->got[CMD_CONFIGURE_82586] = 1;
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: interrupt - configure response received\n", dev->name);
					break;

					/*
					 * Adapter memory configuration
					 */
				case CMD_CONFIGURE_ADAPTER_RESPONSE:
					adapter->got[CMD_CONFIGURE_ADAPTER_MEMORY] = 1;
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: Adapter memory configuration %s.\n", dev->name,
						       adapter->irx_pcb.data.failed ? "failed" : "succeeded");
					break;

					/*
					 * Multicast list loading
					 */
				case CMD_LOAD_MULTICAST_RESPONSE:
					adapter->got[CMD_LOAD_MULTICAST_LIST] = 1;
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: Multicast address list loading %s.\n", dev->name,
						       adapter->irx_pcb.data.failed ? "failed" : "succeeded");
					break;

					/*
					 * Station address setting
					 */
				case CMD_SET_ADDRESS_RESPONSE:
					adapter->got[CMD_SET_STATION_ADDRESS] = 1;
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: Ethernet address setting %s.\n", dev->name,
						       adapter->irx_pcb.data.failed ? "failed" : "succeeded");
					break;


					/*
					 * received board statistics
					 */
				case CMD_NETWORK_STATISTICS_RESPONSE:
					adapter->stats.rx_packets += adapter->irx_pcb.data.netstat.tot_recv;
					adapter->stats.tx_packets += adapter->irx_pcb.data.netstat.tot_xmit;
					adapter->stats.rx_crc_errors += adapter->irx_pcb.data.netstat.err_CRC;
					adapter->stats.rx_frame_errors += adapter->irx_pcb.data.netstat.err_align;
					adapter->stats.rx_fifo_errors += adapter->irx_pcb.data.netstat.err_ovrrun;
					adapter->stats.rx_over_errors += adapter->irx_pcb.data.netstat.err_res;
					adapter->got[CMD_NETWORK_STATISTICS] = 1;
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: interrupt - statistics response received\n", dev->name);
					break;

					/*
					 * sent a packet
					 */
				case CMD_TRANSMIT_PACKET_COMPLETE:
					if (elp_debug >= 3)
						printk(KERN_DEBUG "%s: interrupt - packet sent\n", dev->name);
					if (!netif_running(dev))
						break;
					switch (adapter->irx_pcb.data.xmit_resp.c_stat) {
					case 0xffff:
						adapter->stats.tx_aborted_errors++;
						printk(KERN_INFO "%s: transmit timed out, network cable problem?\n", dev->name);
						break;
					case 0xfffe:
						adapter->stats.tx_fifo_errors++;
						printk(KERN_INFO "%s: transmit timed out, FIFO underrun\n", dev->name);
						break;
					}
					netif_wake_queue(dev);
					break;

					/*
					 * some unknown PCB
					 */
				default:
					printk(KERN_DEBUG "%s: unknown PCB received - %2.2x\n", dev->name, adapter->irx_pcb.command);
					break;
				}
			} else {
				printk(KERN_WARNING "%s: failed to read PCB on interrupt\n", dev->name);
				adapter_reset(dev);
			}
		}

	} while (icount++ < 5 && (inb_status(dev->base_addr) & (ACRF | DONE)));

	prime_rx(dev);

	/*
	 * indicate no longer in interrupt routine
	 */
	spin_unlock(&adapter->lock);
	return IRQ_HANDLED;
}


/******************************************************
 *
 * open the board
 *
 ******************************************************/

static int elp_open(struct net_device *dev)
{
	elp_device *adapter;
	int retval;

	adapter = dev->priv;

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: request to open device\n", dev->name);

	/*
	 * make sure we actually found the device
	 */
	if (adapter == NULL) {
		printk(KERN_ERR "%s: Opening a non-existent physical device\n", dev->name);
		return -EAGAIN;
	}
	/*
	 * disable interrupts on the board
	 */
	outb_control(0, dev);

	/*
	 * clear any pending interrupts
	 */
	inb_command(dev->base_addr);
	adapter_reset(dev);

	/*
	 * no receive PCBs active
	 */
	adapter->rx_active = 0;

	adapter->busy = 0;
	adapter->send_pcb_semaphore = 0;
	adapter->rx_backlog.in = 0;
	adapter->rx_backlog.out = 0;
	
	spin_lock_init(&adapter->lock);

	/*
	 * install our interrupt service routine
	 */
	if ((retval = request_irq(dev->irq, &elp_interrupt, 0, dev->name, dev))) {
		printk(KERN_ERR "%s: could not allocate IRQ%d\n", dev->name, dev->irq);
		return retval;
	}
	if ((retval = request_dma(dev->dma, dev->name))) {
		free_irq(dev->irq, dev);
		printk(KERN_ERR "%s: could not allocate DMA%d channel\n", dev->name, dev->dma);
		return retval;
	}
	adapter->dma_buffer = (void *) dma_mem_alloc(DMA_BUFFER_SIZE);
	if (!adapter->dma_buffer) {
		printk(KERN_ERR "%s: could not allocate DMA buffer\n", dev->name);
		free_dma(dev->dma);
		free_irq(dev->irq, dev);
		return -ENOMEM;
	}
	adapter->dmaing = 0;

	/*
	 * enable interrupts on the board
	 */
	outb_control(CMDE, dev);

	/*
	 * configure adapter memory: we need 10 multicast addresses, default==0
	 */
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: sending 3c505 memory configuration command\n", dev->name);
	adapter->tx_pcb.command = CMD_CONFIGURE_ADAPTER_MEMORY;
	adapter->tx_pcb.data.memconf.cmd_q = 10;
	adapter->tx_pcb.data.memconf.rcv_q = 20;
	adapter->tx_pcb.data.memconf.mcast = 10;
	adapter->tx_pcb.data.memconf.frame = 20;
	adapter->tx_pcb.data.memconf.rcv_b = 20;
	adapter->tx_pcb.data.memconf.progs = 0;
	adapter->tx_pcb.length = sizeof(struct Memconf);
	adapter->got[CMD_CONFIGURE_ADAPTER_MEMORY] = 0;
	if (!send_pcb(dev, &adapter->tx_pcb))
		printk(KERN_ERR "%s: couldn't send memory configuration command\n", dev->name);
	else {
		unsigned long timeout = jiffies + TIMEOUT;
		while (adapter->got[CMD_CONFIGURE_ADAPTER_MEMORY] == 0 && time_before(jiffies, timeout));
		if (time_after_eq(jiffies, timeout))
			TIMEOUT_MSG(__LINE__);
	}


	/*
	 * configure adapter to receive broadcast messages and wait for response
	 */
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: sending 82586 configure command\n", dev->name);
	adapter->tx_pcb.command = CMD_CONFIGURE_82586;
	adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_BROAD;
	adapter->tx_pcb.length = 2;
	adapter->got[CMD_CONFIGURE_82586] = 0;
	if (!send_pcb(dev, &adapter->tx_pcb))
		printk(KERN_ERR "%s: couldn't send 82586 configure command\n", dev->name);
	else {
		unsigned long timeout = jiffies + TIMEOUT;
		while (adapter->got[CMD_CONFIGURE_82586] == 0 && time_before(jiffies, timeout));
		if (time_after_eq(jiffies, timeout))
			TIMEOUT_MSG(__LINE__);
	}

	/* enable burst-mode DMA */
	/* outb(0x1, dev->base_addr + PORT_AUXDMA); */

	/*
	 * queue receive commands to provide buffering
	 */
	prime_rx(dev);
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: %d receive PCBs active\n", dev->name, adapter->rx_active);

	/*
	 * device is now officially open!
	 */

	netif_start_queue(dev);
	return 0;
}


/******************************************************
 *
 * send a packet to the adapter
 *
 ******************************************************/

static int send_packet(struct net_device *dev, struct sk_buff *skb)
{
	elp_device *adapter = dev->priv;
	unsigned long target;
	unsigned long flags;

	/*
	 * make sure the length is even and no shorter than 60 bytes
	 */
	unsigned int nlen = (((skb->len < 60) ? 60 : skb->len) + 1) & (~1);

	if (test_and_set_bit(0, (void *) &adapter->busy)) {
		if (elp_debug >= 2)
			printk(KERN_DEBUG "%s: transmit blocked\n", dev->name);
		return FALSE;
	}

	adapter->stats.tx_bytes += nlen;
	
	/*
	 * send the adapter a transmit packet command. Ignore segment and offset
	 * and make sure the length is even
	 */
	adapter->tx_pcb.command = CMD_TRANSMIT_PACKET;
	adapter->tx_pcb.length = sizeof(struct Xmit_pkt);
	adapter->tx_pcb.data.xmit_pkt.buf_ofs
	    = adapter->tx_pcb.data.xmit_pkt.buf_seg = 0;	/* Unused */
	adapter->tx_pcb.data.xmit_pkt.pkt_len = nlen;

	if (!send_pcb(dev, &adapter->tx_pcb)) {
		adapter->busy = 0;
		return FALSE;
	}
	/* if this happens, we die */
	if (test_and_set_bit(0, (void *) &adapter->dmaing))
		printk(KERN_DEBUG "%s: tx: DMA %d in progress\n", dev->name, adapter->current_dma.direction);

	adapter->current_dma.direction = 1;
	adapter->current_dma.start_time = jiffies;

	if ((unsigned long)(skb->data + nlen) >= MAX_DMA_ADDRESS || nlen != skb->len) {
		memcpy(adapter->dma_buffer, skb->data, nlen);
		memset(adapter->dma_buffer+skb->len, 0, nlen-skb->len);
		target = isa_virt_to_bus(adapter->dma_buffer);
	}
	else {
		target = isa_virt_to_bus(skb->data);
	}
	adapter->current_dma.skb = skb;

	flags=claim_dma_lock();
	disable_dma(dev->dma);
	clear_dma_ff(dev->dma);
	set_dma_mode(dev->dma, 0x48);	/* dma memory -> io */
	set_dma_addr(dev->dma, target);
	set_dma_count(dev->dma, nlen);
	outb_control(adapter->hcr_val | DMAE | TCEN, dev);
	enable_dma(dev->dma);
	release_dma_lock(flags);
	
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: DMA transfer started\n", dev->name);

	return TRUE;
}

/*
 *	The upper layer thinks we timed out
 */
 
static void elp_timeout(struct net_device *dev)
{
	elp_device *adapter = dev->priv;
	int stat;

	stat = inb_status(dev->base_addr);
	printk(KERN_WARNING "%s: transmit timed out, lost %s?\n", dev->name, (stat & ACRF) ? "interrupt" : "command");
	if (elp_debug >= 1)
		printk(KERN_DEBUG "%s: status %#02x\n", dev->name, stat);
	dev->trans_start = jiffies;
	adapter->stats.tx_dropped++;
	netif_wake_queue(dev);
}

/******************************************************
 *
 * start the transmitter
 *    return 0 if sent OK, else return 1
 *
 ******************************************************/

static int elp_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	unsigned long flags;
	elp_device *adapter = dev->priv;
	
	spin_lock_irqsave(&adapter->lock, flags);
	check_3c505_dma(dev);

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: request to send packet of length %d\n", dev->name, (int) skb->len);

	netif_stop_queue(dev);
	
	/*
	 * send the packet at skb->data for skb->len
	 */
	if (!send_packet(dev, skb)) {
		if (elp_debug >= 2) {
			printk(KERN_DEBUG "%s: failed to transmit packet\n", dev->name);
		}
		spin_unlock_irqrestore(&adapter->lock, flags);
		return 1;
	}
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: packet of length %d sent\n", dev->name, (int) skb->len);

	/*
	 * start the transmit timeout
	 */
	dev->trans_start = jiffies;

	prime_rx(dev);
	spin_unlock_irqrestore(&adapter->lock, flags);
	netif_start_queue(dev);
	return 0;
}

/******************************************************
 *
 * return statistics on the board
 *
 ******************************************************/

static struct net_device_stats *elp_get_stats(struct net_device *dev)
{
	elp_device *adapter = (elp_device *) dev->priv;

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: request for stats\n", dev->name);

	/* If the device is closed, just return the latest stats we have,
	   - we cannot ask from the adapter without interrupts */
	if (!netif_running(dev))
		return &adapter->stats;

	/* send a get statistics command to the board */
	adapter->tx_pcb.command = CMD_NETWORK_STATISTICS;
	adapter->tx_pcb.length = 0;
	adapter->got[CMD_NETWORK_STATISTICS] = 0;
	if (!send_pcb(dev, &adapter->tx_pcb))
		printk(KERN_ERR "%s: couldn't send get statistics command\n", dev->name);
	else {
		unsigned long timeout = jiffies + TIMEOUT;
		while (adapter->got[CMD_NETWORK_STATISTICS] == 0 && time_before(jiffies, timeout));
		if (time_after_eq(jiffies, timeout)) {
			TIMEOUT_MSG(__LINE__);
			return &adapter->stats;
		}
	}

	/* statistics are now up to date */
	return &adapter->stats;
}


static void netdev_get_drvinfo(struct net_device *dev,
			       struct ethtool_drvinfo *info)
{
	strcpy(info->driver, DRV_NAME);
	strcpy(info->version, DRV_VERSION);
	sprintf(info->bus_info, "ISA 0x%lx", dev->base_addr);
}

static u32 netdev_get_msglevel(struct net_device *dev)
{
	return debug;
}

static void netdev_set_msglevel(struct net_device *dev, u32 level)
{
	debug = level;
}

static struct ethtool_ops netdev_ethtool_ops = {
	.get_drvinfo		= netdev_get_drvinfo,
	.get_msglevel		= netdev_get_msglevel,
	.set_msglevel		= netdev_set_msglevel,
};

/******************************************************
 *
 * close the board
 *
 ******************************************************/

static int elp_close(struct net_device *dev)
{
	elp_device *adapter;

	adapter = dev->priv;

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: request to close device\n", dev->name);

	netif_stop_queue(dev);

	/* Someone may request the device statistic information even when
	 * the interface is closed. The following will update the statistics
	 * structure in the driver, so we'll be able to give current statistics.
	 */
	(void) elp_get_stats(dev);

	/*
	 * disable interrupts on the board
	 */
	outb_control(0, dev);

	/*
	 * release the IRQ
	 */
	free_irq(dev->irq, dev);

	free_dma(dev->dma);
	free_pages((unsigned long) adapter->dma_buffer, get_order(DMA_BUFFER_SIZE));

	return 0;
}


/************************************************************
 *
 * Set multicast list
 * num_addrs==0: clear mc_list
 * num_addrs==-1: set promiscuous mode
 * num_addrs>0: set mc_list
 *
 ************************************************************/

static void elp_set_mc_list(struct net_device *dev)
{
	elp_device *adapter = (elp_device *) dev->priv;
	struct dev_mc_list *dmi = dev->mc_list;
	int i;
	unsigned long flags;

	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: request to set multicast list\n", dev->name);

	spin_lock_irqsave(&adapter->lock, flags);
	
	if (!(dev->flags & (IFF_PROMISC | IFF_ALLMULTI))) {
		/* send a "load multicast list" command to the board, max 10 addrs/cmd */
		/* if num_addrs==0 the list will be cleared */
		adapter->tx_pcb.command = CMD_LOAD_MULTICAST_LIST;
		adapter->tx_pcb.length = 6 * dev->mc_count;
		for (i = 0; i < dev->mc_count; i++) {
			memcpy(adapter->tx_pcb.data.multicast[i], dmi->dmi_addr, 6);
			dmi = dmi->next;
		}
		adapter->got[CMD_LOAD_MULTICAST_LIST] = 0;
		if (!send_pcb(dev, &adapter->tx_pcb))
			printk(KERN_ERR "%s: couldn't send set_multicast command\n", dev->name);
		else {
			unsigned long timeout = jiffies + TIMEOUT;
			while (adapter->got[CMD_LOAD_MULTICAST_LIST] == 0 && time_before(jiffies, timeout));
			if (time_after_eq(jiffies, timeout)) {
				TIMEOUT_MSG(__LINE__);
			}
		}
		if (dev->mc_count)
			adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_BROAD | RECV_MULTI;
		else		/* num_addrs == 0 */
			adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_BROAD;
	} else
		adapter->tx_pcb.data.configure = NO_LOOPBACK | RECV_PROMISC;
	/*
	 * configure adapter to receive messages (as specified above)
	 * and wait for response
	 */
	if (elp_debug >= 3)
		printk(KERN_DEBUG "%s: sending 82586 configure command\n", dev->name);
	adapter->tx_pcb.command = CMD_CONFIGURE_82586;
	adapter->tx_pcb.length = 2;
	adapter->got[CMD_CONFIGURE_82586] = 0;
	if (!send_pcb(dev, &adapter->tx_pcb))
	{
		spin_unlock_irqrestore(&adapter->lock, flags);
		printk(KERN_ERR "%s: couldn't send 82586 configure command\n", dev->name);
	}
	else {
		unsigned long timeout = jiffies + TIMEOUT;
		spin_unlock_irqrestore(&adapter->lock, flags);
		while (adapter->got[CMD_CONFIGURE_82586] == 0 && time_before(jiffies, timeout));
		if (time_after_eq(jiffies, timeout))
			TIMEOUT_MSG(__LINE__);
	}
}

/************************************************************
 *
 * A couple of tests to see if there's 3C505 or not
 * Called only by elp_autodetect
 ************************************************************/

static int __init elp_sense(struct net_device *dev)
{
	int addr = dev->base_addr;
	const char *name = dev->name;
	byte orig_HSR;

	if (!request_region(addr, ELP_IO_EXTENT, "3c505"))
		return -ENODEV;

	orig_HSR = inb_status(addr);

	if (elp_debug > 0)
		printk(search_msg, name, addr);

	if (orig_HSR == 0xff) {
		if (elp_debug > 0)
			printk(notfound_msg, 1);
		goto out;
	}

	/* Wait for a while; the adapter may still be booting up */
	if (elp_debug > 0)
		printk(stilllooking_msg);

	if (orig_HSR & DIR) {
		/* If HCR.DIR is up, we pull it down. HSR.DIR should follow. */
		outb(0, dev->base_addr + PORT_CONTROL);
		msleep(300);
		if (inb_status(addr) & DIR) {
			if (elp_debug > 0)
				printk(notfound_msg, 2);
			goto out;
		}
	} else {
		/* If HCR.DIR is down, we pull it up. HSR.DIR should follow. */
		outb(DIR, dev->base_addr + PORT_CONTROL);
		msleep(300);
		if (!(inb_status(addr) & DIR)) {
			if (elp_debug > 0)
				printk(notfound_msg, 3);
			goto out;
		}
	}
	/*
	 * It certainly looks like a 3c505.
	 */
	if (elp_debug > 0)
		printk(found_msg);

	return 0;
out:
	release_region(addr, ELP_IO_EXTENT);
	return -ENODEV;
}

/*************************************************************
 *
 * Search through addr_list[] and try to find a 3C505
 * Called only by eplus_probe
 *************************************************************/

static int __init elp_autodetect(struct net_device *dev)
{
	int idx = 0;

	/* if base address set, then only check that address
	   otherwise, run through the table */
	if (dev->base_addr != 0) {	/* dev->base_addr == 0 ==> plain autodetect */
		if (elp_sense(dev) == 0)
			return dev->base_addr;
	} else
		while ((dev->base_addr = addr_list[idx++])) {
			if (elp_sense(dev) == 0)
				return dev->base_addr;
		}

	/* could not find an adapter */
	if (elp_debug > 0)
		printk(couldnot_msg, dev->name);

	return 0;		/* Because of this, the layer above will return -ENODEV */
}


/******************************************************
 *
 * probe for an Etherlink Plus board at the specified address
 *
 ******************************************************/

/* There are three situations we need to be able to detect here:

 *  a) the card is idle
 *  b) the card is still booting up
 *  c) the card is stuck in a strange state (some DOS drivers do this)
 *
 * In case (a), all is well.  In case (b), we wait 10 seconds to see if the
 * card finishes booting, and carry on if so.  In case (c), we do a hard reset,
 * loop round, and hope for the best.
 *
 * This is all very unpleasant, but hopefully avoids the problems with the old
 * probe code (which had a 15-second delay if the card was idle, and didn't
 * work at all if it was in a weird state).
 */

static int __init elplus_setup(struct net_device *dev)
{
	elp_device *adapter = dev->priv;
	int i, tries, tries1, okay;
	unsigned long timeout;
	unsigned long cookie = 0;
	int err = -ENODEV;

	SET_MODULE_OWNER(dev);

	/*
	 *  setup adapter structure
	 */

	dev->base_addr = elp_autodetect(dev);
	if (!dev->base_addr)
		return -ENODEV;

	adapter->send_pcb_semaphore = 0;

	for (tries1 = 0; tries1 < 3; tries1++) {
		outb_control((adapter->hcr_val | CMDE) & ~DIR, dev);
		/* First try to write just one byte, to see if the card is
		 * responding at all normally.
		 */
		timeout = jiffies + 5*HZ/100;
		okay = 0;
		while (time_before(jiffies, timeout) && !(inb_status(dev->base_addr) & HCRE));
		if ((inb_status(dev->base_addr) & HCRE)) {
			outb_command(0, dev->base_addr);	/* send a spurious byte */
			timeout = jiffies + 5*HZ/100;
			while (time_before(jiffies, timeout) && !(inb_status(dev->base_addr) & HCRE));
			if (inb_status(dev->base_addr) & HCRE)
				okay = 1;
		}
		if (!okay) {
			/* Nope, it's ignoring the command register.  This means that
			 * either it's still booting up, or it's died.
			 */
			printk(KERN_ERR "%s: command register wouldn't drain, ", dev->name);
			if ((inb_status(dev->base_addr) & 7) == 3) {
				/* If the adapter status is 3, it *could* still be booting.
				 * Give it the benefit of the doubt for 10 seconds.
				 */
				printk("assuming 3c505 still starting\n");
				timeout = jiffies + 10*HZ;
				while (time_before(jiffies, timeout) && (inb_status(dev->base_addr) & 7));
				if (inb_status(dev->base_addr) & 7) {
					printk(KERN_ERR "%s: 3c505 failed to start\n", dev->name);
				} else {
					okay = 1;  /* It started */
				}
			} else {
				/* Otherwise, it must just be in a strange
				 * state.  We probably need to kick it.
				 */
				printk("3c505 is sulking\n");
			}
		}
		for (tries = 0; tries < 5 && okay; tries++) {

			/*
			 * Try to set the Ethernet address, to make sure that the board
			 * is working.
			 */
			adapter->tx_pcb.command = CMD_STATION_ADDRESS;
			adapter->tx_pcb.length = 0;
			cookie = probe_irq_on();
			if (!send_pcb(dev, &adapter->tx_pcb)) {
				printk(KERN_ERR "%s: could not send first PCB\n", dev->name);
				probe_irq_off(cookie);
				continue;
			}
			if (!receive_pcb(dev, &adapter->rx_pcb)) {
				printk(KERN_ERR "%s: could not read first PCB\n", dev->name);
				probe_irq_off(cookie);
				continue;
			}
			if ((adapter->rx_pcb.command != CMD_ADDRESS_RESPONSE) ||
			    (adapter->rx_pcb.length != 6)) {
				printk(KERN_ERR "%s: first PCB wrong (%d, %d)\n", dev->name, adapter->rx_pcb.command, adapter->rx_pcb.length);
				probe_irq_off(cookie);
				continue;
			}
			goto okay;
		}
		/* It's broken.  Do a hard reset to re-initialise the board,
		 * and try again.
		 */
		printk(KERN_INFO "%s: resetting adapter\n", dev->name);
		outb_control(adapter->hcr_val | FLSH | ATTN, dev);
		outb_control(adapter->hcr_val & ~(FLSH | ATTN), dev);
	}
	printk(KERN_ERR "%s: failed to initialise 3c505\n", dev->name);
	goto out;

      okay:
	if (dev->irq) {		/* Is there a preset IRQ? */
		int rpt = probe_irq_off(cookie);
		if (dev->irq != rpt) {
			printk(KERN_WARNING "%s: warning, irq %d configured but %d detected\n", dev->name, dev->irq, rpt);
		}
		/* if dev->irq == probe_irq_off(cookie), all is well */
	} else		       /* No preset IRQ; just use what we can detect */
		dev->irq = probe_irq_off(cookie);
	switch (dev->irq) {    /* Legal, sane? */
	case 0:
		printk(KERN_ERR "%s: IRQ probe failed: check 3c505 jumpers.\n",
		       dev->name);
		goto out;
	case 1:
	case 6:
	case 8:
	case 13:
		printk(KERN_ERR "%s: Impossible IRQ %d reported by probe_irq_off().\n",
		       dev->name, dev->irq);
		       goto out;
	}
	/*
	 *  Now we have the IRQ number so we can disable the interrupts from
	 *  the board until the board is opened.
	 */
	outb_control(adapter->hcr_val & ~CMDE, dev);

	/*
	 * copy Ethernet address into structure
	 */
	for (i = 0; i < 6; i++)
		dev->dev_addr[i] = adapter->rx_pcb.data.eth_addr[i];

	/* find a DMA channel */
	if (!dev->dma) {
		if (dev->mem_start) {
			dev->dma = dev->mem_start & 7;
		}
		else {
			printk(KERN_WARNING "%s: warning, DMA channel not specified, using default\n", dev->name);
			dev->dma = ELP_DMA;
		}
	}

	/*
	 * print remainder of startup message
	 */
	printk(KERN_INFO "%s: 3c505 at %#lx, irq %d, dma %d, ",
	       dev->name, dev->base_addr, dev->irq, dev->dma);
	printk("addr %02x:%02x:%02x:%02x:%02x:%02x, ",
	       dev->dev_addr[0], dev->dev_addr[1], dev->dev_addr[2],
	       dev->dev_addr[3], dev->dev_addr[4], dev->dev_addr[5]);

	/*
	 * read more information from the adapter
	 */

	adapter->tx_pcb.command = CMD_ADAPTER_INFO;
	adapter->tx_pcb.length = 0;
	if (!send_pcb(dev, &adapter->tx_pcb) ||
	    !receive_pcb(dev, &adapter->rx_pcb) ||
	    (adapter->rx_pcb.command != CMD_ADAPTER_INFO_RESPONSE) ||
	    (adapter->rx_pcb.length != 10)) {
		printk("not responding to second PCB\n");
	}
	printk("rev %d.%d, %dk\n", adapter->rx_pcb.data.info.major_vers, adapter->rx_pcb.data.info.minor_vers, adapter->rx_pcb.data.info.RAM_sz);

	/*
	 * reconfigure the adapter memory to better suit our purposes
	 */
	adapter->tx_pcb.command = CMD_CONFIGURE_ADAPTER_MEMORY;
	adapter->tx_pcb.length = 12;
	adapter->tx_pcb.data.memconf.cmd_q = 8;
	adapter->tx_pcb.data.memconf.rcv_q = 8;
	adapter->tx_pcb.data.memconf.mcast = 10;
	adapter->tx_pcb.data.memconf.frame = 10;
	adapter->tx_pcb.data.memconf.rcv_b = 10;
	adapter->tx_pcb.data.memconf.progs = 0;
	if (!send_pcb(dev, &adapter->tx_pcb) ||
	    !receive_pcb(dev, &adapter->rx_pcb) ||
	    (adapter->rx_pcb.command != CMD_CONFIGURE_ADAPTER_RESPONSE) ||
	    (adapter->rx_pcb.length != 2)) {
		printk(KERN_ERR "%s: could not configure adapter memory\n", dev->name);
	}
	if (adapter->rx_pcb.data.configure) {
		printk(KERN_ERR "%s: adapter configuration failed\n", dev->name);
	}

	dev->open = elp_open;				/* local */
	dev->stop = elp_close;				/* local */
	dev->get_stats = elp_get_stats;			/* local */
	dev->hard_start_xmit = elp_start_xmit;		/* local */
	dev->tx_timeout = elp_timeout;			/* local */
	dev->watchdog_timeo = 10*HZ;
	dev->set_multicast_list = elp_set_mc_list;	/* local */
	dev->ethtool_ops = &netdev_ethtool_ops;		/* local */

	memset(&(adapter->stats), 0, sizeof(struct net_device_stats));
	dev->mem_start = dev->mem_end = 0;

	err = register_netdev(dev);
	if (err)
		goto out;

	return 0;
out:
	release_region(dev->base_addr, ELP_IO_EXTENT);
	return err;
}

#ifndef MODULE
struct net_device * __init elplus_probe(int unit)
{
	struct net_device *dev = alloc_etherdev(sizeof(elp_device));
	int err;
	if (!dev)
		return ERR_PTR(-ENOMEM);

	sprintf(dev->name, "eth%d", unit);
	netdev_boot_setup_check(dev);

	err = elplus_setup(dev);
	if (err) {
		free_netdev(dev);
		return ERR_PTR(err);
	}
	return dev;
}

#else
static struct net_device *dev_3c505[ELP_MAX_CARDS];
static int io[ELP_MAX_CARDS];
static int irq[ELP_MAX_CARDS];
static int dma[ELP_MAX_CARDS];
module_param_array(io, int, NULL, 0);
module_param_array(irq, int, NULL, 0);
module_param_array(dma, int, NULL, 0);
MODULE_PARM_DESC(io, "EtherLink Plus I/O base address(es)");
MODULE_PARM_DESC(irq, "EtherLink Plus IRQ number(s) (assigned)");
MODULE_PARM_DESC(dma, "EtherLink Plus DMA channel(s)");

int init_module(void)
{
	int this_dev, found = 0;

	for (this_dev = 0; this_dev < ELP_MAX_CARDS; this_dev++) {
		struct net_device *dev = alloc_etherdev(sizeof(elp_device));
		if (!dev)
			break;

		dev->irq = irq[this_dev];
		dev->base_addr = io[this_dev];
		if (dma[this_dev]) {
			dev->dma = dma[this_dev];
		} else {
			dev->dma = ELP_DMA;
			printk(KERN_WARNING "3c505.c: warning, using default DMA channel,\n");
		}
		if (io[this_dev] == 0) {
			if (this_dev) {
				free_netdev(dev);
				break;
			}
			printk(KERN_NOTICE "3c505.c: module autoprobe not recommended, give io=xx.\n");
		}
		if (elplus_setup(dev) != 0) {
			printk(KERN_WARNING "3c505.c: Failed to register card at 0x%x.\n", io[this_dev]);
			free_netdev(dev);
			break;
		}
		dev_3c505[this_dev] = dev;
		found++;
	}
	if (!found)
		return -ENODEV;
	return 0;
}

void cleanup_module(void)
{
	int this_dev;

	for (this_dev = 0; this_dev < ELP_MAX_CARDS; this_dev++) {
		struct net_device *dev = dev_3c505[this_dev];
		if (dev) {
			unregister_netdev(dev);
			release_region(dev->base_addr, ELP_IO_EXTENT);
			free_netdev(dev);
		}
	}
}

#endif				/* MODULE */
MODULE_LICENSE("GPL");