drivers/isdn/i4l/isdn_v110.c

   1 /* $Id: isdn_v110.c,v 1.1.2.2 2004/01/12 22:37:19 keil Exp $
   2  *
   3  * Linux ISDN subsystem, V.110 related functions (linklevel).
   4  *
   5  * Copyright by Thomas Pfeiffer (pfeiffer@pds.de)
   6  *
   7  * This software may be used and distributed according to the terms
   8  * of the GNU General Public License, incorporated herein by reference.
   9  *
  10  */
  11
  12 #include <linux/string.h>
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/mm.h>
  16 #include <linux/delay.h>
  17
  18 #include <linux/isdn.h>
  19 #include "isdn_v110.h"
  20
  21 #undef ISDN_V110_DEBUG
  22
  23 char *isdn_v110_revision = "$Revision: 1.1.2.2 $";
  24
  25 #define V110_38400 255
  26 #define V110_19200  15
  27 #define V110_9600    3
  28
  29 /*
  30  * The following data are precoded matrices, online and offline matrix
  31  * for 9600, 19200 und 38400, respectively
  32  */
  33 static unsigned char V110_OnMatrix_9600[] =
  34 {0xfc, 0xfc, 0xfc, 0xfc, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff,
  35  0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd,
  36  0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff,
  37  0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xfd};
  38
  39 static unsigned char V110_OffMatrix_9600[] =
  40 {0xfc, 0xfc, 0xfc, 0xfc, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  41  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  42  0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  43  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
  44
  45 static unsigned char V110_OnMatrix_19200[] =
  46 {0xf0, 0xf0, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7,
  47  0xfd, 0xff, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7, 0xff, 0xf7};
  48
  49 static unsigned char V110_OffMatrix_19200[] =
  50 {0xf0, 0xf0, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
  51  0xfd, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
  52
  53 static unsigned char V110_OnMatrix_38400[] =
  54 {0x00, 0x7f, 0x7f, 0x7f, 0x7f, 0xfd, 0x7f, 0x7f, 0x7f, 0x7f};
  55
  56 static unsigned char V110_OffMatrix_38400[] =
  57 {0x00, 0xff, 0xff, 0xff, 0xff, 0xfd, 0xff, 0xff, 0xff, 0xff};
  58
  59 /*
  60  * FlipBits reorders sequences of keylen bits in one byte.
  61  * E.g. source order 7654321 will be converted to 45670123 when keylen = 4,
  62  * and to 67452301 when keylen = 2. This is necessary because ordering on
  63  * the isdn line is the other way.
  64  */
  65 static __inline unsigned char
  66 FlipBits(unsigned char c, int keylen)
  67 {
  68         unsigned char b = c;
  69         unsigned char bit = 128;
  70         int i;
  71         int j;
  72         int hunks = (8 / keylen);
  73
  74         c = 0;
  75         for (i = 0; i < hunks; i++) {
  76                 for (j = 0; j < keylen; j++) {
  77                         if (b & (bit >> j))
  78                                 c |= bit >> (keylen - j - 1);
  79                 }
  80                 bit >>= keylen;
  81         }
  82         return c;
  83 }
  84
  85
  86 /* isdn_v110_open allocates and initializes private V.110 data
  87  * structures and returns a pointer to these.
  88  */
  89 static isdn_v110_stream *
  90 isdn_v110_open(unsigned char key, int hdrlen, int maxsize)
  91 {
  92         int i;
  93         isdn_v110_stream *v;
  94
  95         if ((v = kmalloc(sizeof(isdn_v110_stream), GFP_ATOMIC)) == NULL)
  96                 return NULL;
  97         memset(v, 0, sizeof(isdn_v110_stream));
  98         v->key = key;
  99         v->nbits = 0;
 100         for (i = 0; key & (1 << i); i++)
 101                 v->nbits++;
 102
 103         v->nbytes = 8 / v->nbits;
 104         v->decodelen = 0;
 105
 106         switch (key) {
 107                 case V110_38400:
 108                         v->OnlineFrame = V110_OnMatrix_38400;
 109                         v->OfflineFrame = V110_OffMatrix_38400;
 110                         break;
 111                 case V110_19200:
 112                         v->OnlineFrame = V110_OnMatrix_19200;
 113                         v->OfflineFrame = V110_OffMatrix_19200;
 114                         break;
 115                 default:
 116                         v->OnlineFrame = V110_OnMatrix_9600;
 117                         v->OfflineFrame = V110_OffMatrix_9600;
 118                         break;
 119         }
 120         v->framelen = v->nbytes * 10;
 121         v->SyncInit = 5;
 122         v->introducer = 0;
 123         v->dbit = 1;
 124         v->b = 0;
 125         v->skbres = hdrlen;
 126         v->maxsize = maxsize - hdrlen;
 127         if ((v->encodebuf = kmalloc(maxsize, GFP_ATOMIC)) == NULL) {
 128                 kfree(v);
 129                 return NULL;
 130         }
 131         return v;
 132 }
 133
 134 /* isdn_v110_close frees private V.110 data structures */
 135 void
 136 isdn_v110_close(isdn_v110_stream * v)
 137 {
 138         if (v == NULL)
 139                 return;
 140 #ifdef ISDN_V110_DEBUG
 141         printk(KERN_DEBUG "v110 close\n");
 142 #endif
 143         kfree(v->encodebuf);
 144         kfree(v);
 145 }
 146
 147
 148 /*
 149  * ValidHeaderBytes return the number of valid bytes in v->decodebuf
 150  */
 151 static int
 152 ValidHeaderBytes(isdn_v110_stream * v)
 153 {
 154         int i;
 155         for (i = 0; (i < v->decodelen) && (i < v->nbytes); i++)
 156                 if ((v->decodebuf[i] & v->key) != 0)
 157                         break;
 158         return i;
 159 }
 160
 161 /*
 162  * SyncHeader moves the decodebuf ptr to the next valid header
 163  */
 164 static void
 165 SyncHeader(isdn_v110_stream * v)
 166 {
 167         unsigned char *rbuf = v->decodebuf;
 168         int len = v->decodelen;
 169
 170         if (len == 0)
 171                 return;
 172         for (rbuf++, len--; len > 0; len--, rbuf++)     /* such den SyncHeader in buf ! */
 173                 if ((*rbuf & v->key) == 0)      /* erstes byte gefunden ?       */
 174                         break;  /* jupp!                        */
 175         if (len)
 176                 memcpy(v->decodebuf, rbuf, len);
 177
 178         v->decodelen = len;
 179 #ifdef ISDN_V110_DEBUG
 180         printk(KERN_DEBUG "isdn_v110: Header resync\n");
 181 #endif
 182 }
 183
 184 /* DecodeMatrix takes n (n>=1) matrices (v110 frames, 10 bytes) where
 185    len is the number of matrix-lines. len must be a multiple of 10, i.e.
 186    only complete matices must be given.
 187    From these, netto data is extracted and returned in buf. The return-value
 188    is the bytecount of the decoded data.
 189  */
 190 static int
 191 DecodeMatrix(isdn_v110_stream * v, unsigned char *m, int len, unsigned char *buf)
 192 {
 193         int line = 0;
 194         int buflen = 0;
 195         int mbit = 64;
 196         int introducer = v->introducer;
 197         int dbit = v->dbit;
 198         unsigned char b = v->b;
 199
 200         while (line < len) {    /* Are we done with all lines of the matrix? */
 201                 if ((line % 10) == 0) { /* the 0. line of the matrix is always 0 ! */
 202                         if (m[line] != 0x00) {  /* not 0 ? -> error! */
 203 #ifdef ISDN_V110_DEBUG
 204                                 printk(KERN_DEBUG "isdn_v110: DecodeMatrix, V110 Bad Header\n");
 205                                 /* returning now is not the right thing, though :-( */
 206 #endif
 207                         }
 208                         line++; /* next line of matrix */
 209                         continue;
 210                 } else if ((line % 10) == 5) {  /* in line 5 there's only e-bits ! */
 211                         if ((m[line] & 0x70) != 0x30) { /* 011 has to be at the beginning! */
 212 #ifdef ISDN_V110_DEBUG
 213                                 printk(KERN_DEBUG "isdn_v110: DecodeMatrix, V110 Bad 5th line\n");
 214                                 /* returning now is not the right thing, though :-( */
 215 #endif
 216                         }
 217                         line++; /* next line */
 218                         continue;
 219                 } else if (!introducer) {       /* every byte starts with 10 (stopbit, startbit) */
 220                         introducer = (m[line] & mbit) ? 0 : 1;  /* current bit of the matrix */
 221                       next_byte:
 222                         if (mbit > 2) { /* was it the last bit in this line ? */
 223                                 mbit >>= 1;     /* no -> take next */
 224                                 continue;
 225                         }       /* otherwise start with leftmost bit in the next line */
 226                         mbit = 64;
 227                         line++;
 228                         continue;
 229                 } else {        /* otherwise we need to set a data bit */
 230                         if (m[line] & mbit)     /* was that bit set in the matrix ? */
 231                                 b |= dbit;      /* yes -> set it in the data byte */
 232                         else
 233                                 b &= dbit - 1;  /* no -> clear it in the data byte */
 234                         if (dbit < 128) /* is that data byte done ? */
 235                                 dbit <<= 1;     /* no, got the next bit */
 236                         else {  /* data byte is done */
 237                                 buf[buflen++] = b;      /* copy byte into the output buffer */
 238                                 introducer = b = 0;     /* init of the intro sequence and of the data byte */
 239                                 dbit = 1;       /* next we look for the 0th bit */
 240                         }
 241                         goto next_byte; /* look for next bit in the matrix */
 242                 }
 243         }
 244         v->introducer = introducer;
 245         v->dbit = dbit;
 246         v->b = b;
 247         return buflen;          /* return number of bytes in the output buffer */
 248 }
 249
 250 /*
 251  * DecodeStream receives V.110 coded data from the input stream. It recovers the
 252  * original frames.
 253  * The input stream doesn't need to be framed
 254  */
 255 struct sk_buff *
 256 isdn_v110_decode(isdn_v110_stream * v, struct sk_buff *skb)
 257 {
 258         int i;
 259         int j;
 260         int len;
 261         unsigned char *v110_buf;
 262         unsigned char *rbuf;
 263
 264         if (!skb) {
 265                 printk(KERN_WARNING "isdn_v110_decode called with NULL skb!\n");
 266                 return NULL;
 267         }
 268         rbuf = skb->data;
 269         len = skb->len;
 270         if (v == NULL) {
 271                 /* invalid handle, no chance to proceed */
 272                 printk(KERN_WARNING "isdn_v110_decode called with NULL stream!\n");
 273                 dev_kfree_skb(skb);
 274                 return NULL;
 275         }
 276         if (v->decodelen == 0)  /* cache empty?               */
 277                 for (; len > 0; len--, rbuf++)  /* scan for SyncHeader in buf */
 278                         if ((*rbuf & v->key) == 0)
 279                                 break;  /* found first byte           */
 280         if (len == 0) {
 281                 dev_kfree_skb(skb);
 282                 return NULL;
 283         }
 284         /* copy new data to decode-buffer */
 285         memcpy(&(v->decodebuf[v->decodelen]), rbuf, len);
 286         v->decodelen += len;
 287       ReSync:
 288         if (v->decodelen < v->nbytes) { /* got a new header ? */
 289                 dev_kfree_skb(skb);
 290                 return NULL;    /* no, try later      */
 291         }
 292         if (ValidHeaderBytes(v) != v->nbytes) { /* is that a valid header? */
 293                 SyncHeader(v);  /* no -> look for header */
 294                 goto ReSync;
 295         }
 296         len = (v->decodelen - (v->decodelen % (10 * v->nbytes))) / v->nbytes;
 297         if ((v110_buf = kmalloc(len, GFP_ATOMIC)) == NULL) {
 298                 printk(KERN_WARNING "isdn_v110_decode: Couldn't allocate v110_buf\n");
 299                 dev_kfree_skb(skb);
 300                 return NULL;
 301         }
 302         for (i = 0; i < len; i++) {
 303                 v110_buf[i] = 0;
 304                 for (j = 0; j < v->nbytes; j++)
 305                         v110_buf[i] |= (v->decodebuf[(i * v->nbytes) + j] & v->key) << (8 - ((j + 1) * v->nbits));
 306                 v110_buf[i] = FlipBits(v110_buf[i], v->nbits);
 307         }
 308         v->decodelen = (v->decodelen % (10 * v->nbytes));
 309         memcpy(v->decodebuf, &(v->decodebuf[len * v->nbytes]), v->decodelen);
 310
 311         skb_trim(skb, DecodeMatrix(v, v110_buf, len, skb->data));
 312         kfree(v110_buf);
 313         if (skb->len)
 314                 return skb;
 315         else {
 316                 kfree_skb(skb);
 317                 return NULL;
 318         }
 319 }
 320
 321 /* EncodeMatrix takes input data in buf, len is the bytecount.
 322    Data is encoded into v110 frames in m. Return value is the number of
 323    matrix-lines generated.
 324  */
 325 static int
 326 EncodeMatrix(unsigned char *buf, int len, unsigned char *m, int mlen)
 327 {
 328         int line = 0;
 329         int i = 0;
 330         int mbit = 128;
 331         int dbit = 1;
 332         int introducer = 3;
 333         int ibit[] = {0, 1, 1};
 334
 335         while ((i < len) && (line < mlen)) {    /* while we still have input data */
 336                 switch (line % 10) {    /* in which line of the matrix are we? */
 337                         case 0:
 338                                 m[line++] = 0x00;       /* line 0 is always 0 */
 339                                 mbit = 128;     /* go on with the 7th bit */
 340                                 break;
 341                         case 5:
 342                                 m[line++] = 0xbf;       /* line 5 is always 10111111 */
 343                                 mbit = 128;     /* go on with the 7th bit */
 344                                 break;
 345                 }
 346                 if (line >= mlen) {
 347                         printk(KERN_WARNING "isdn_v110 (EncodeMatrix): buffer full!\n");
 348                         return line;
 349                 }
 350         next_bit:
 351                 switch (mbit) { /* leftmost or rightmost bit ? */
 352                         case 1:
 353                                 line++; /* rightmost -> go to next line */
 354                                 if (line >= mlen) {
 355                                         printk(KERN_WARNING "isdn_v110 (EncodeMatrix): buffer full!\n");
 356                                         return line;
 357                                 }
 358                         case 128:
 359                                 m[line] = 128;  /* leftmost -> set byte to 1000000 */
 360                                 mbit = 64;      /* current bit in the matrix line */
 361                                 continue;
 362                 }
 363                 if (introducer) {       /* set 110 sequence ? */
 364                         introducer--;   /* set on digit less */
 365                         m[line] |= ibit[introducer] ? mbit : 0; /* set corresponding bit */
 366                         mbit >>= 1;     /* bit of matrix line  >> 1 */
 367                         goto next_bit;  /* and go on there */
 368                 }               /* else push data bits into the matrix! */
 369                 m[line] |= (buf[i] & dbit) ? mbit : 0;  /* set data bit in matrix */
 370                 if (dbit == 128) {      /* was it the last one? */
 371                         dbit = 1;       /* then go on with first bit of  */
 372                         i++;            /* next byte in input buffer */
 373                         if (i < len)    /* input buffer done ? */
 374                                 introducer = 3; /* no, write introducer 110 */
 375                         else {  /* input buffer done ! */
 376                                 m[line] |= (mbit - 1) & 0xfe;   /* set remaining bits in line to 1 */
 377                                 break;
 378                         }
 379                 } else          /* not the last data bit */
 380                         dbit <<= 1;     /* then go to next data bit */
 381                 mbit >>= 1;     /* go to next bit of matrix */
 382                 goto next_bit;
 383
 384         }
 385         /* if necessary, generate remaining lines of the matrix... */
 386         if ((line) && ((line + 10) < mlen))
 387                 switch (++line % 10) {
 388                         case 1:
 389                                 m[line++] = 0xfe;
 390                         case 2:
 391                                 m[line++] = 0xfe;
 392                         case 3:
 393                                 m[line++] = 0xfe;
 394                         case 4:
 395                                 m[line++] = 0xfe;
 396                         case 5:
 397                                 m[line++] = 0xbf;
 398                         case 6:
 399                                 m[line++] = 0xfe;
 400                         case 7:
 401                                 m[line++] = 0xfe;
 402                         case 8:
 403                                 m[line++] = 0xfe;
 404                         case 9:
 405                                 m[line++] = 0xfe;
 406                 }
 407         return line;            /* that's how many lines we have */
 408 }
 409
 410 /*
 411  * Build a sync frame.
 412  */
 413 static struct sk_buff *
 414 isdn_v110_sync(isdn_v110_stream *v)
 415 {
 416         struct sk_buff *skb;
 417
 418         if (v == NULL) {
 419                 /* invalid handle, no chance to proceed */
 420                 printk(KERN_WARNING "isdn_v110_sync called with NULL stream!\n");
 421                 return NULL;
 422         }
 423         if ((skb = dev_alloc_skb(v->framelen + v->skbres))) {
 424                 skb_reserve(skb, v->skbres);
 425                 memcpy(skb_put(skb, v->framelen), v->OfflineFrame, v->framelen);
 426         }
 427         return skb;
 428 }
 429
 430 /*
 431  * Build an idle frame.
 432  */
 433 static struct sk_buff *
 434 isdn_v110_idle(isdn_v110_stream *v)
 435 {
 436         struct sk_buff *skb;
 437
 438         if (v == NULL) {
 439                 /* invalid handle, no chance to proceed */
 440                 printk(KERN_WARNING "isdn_v110_sync called with NULL stream!\n");
 441                 return NULL;
 442         }
 443         if ((skb = dev_alloc_skb(v->framelen + v->skbres))) {
 444                 skb_reserve(skb, v->skbres);
 445                 memcpy(skb_put(skb, v->framelen), v->OnlineFrame, v->framelen);
 446         }
 447         return skb;
 448 }
 449
 450 struct sk_buff *
 451 isdn_v110_encode(isdn_v110_stream * v, struct sk_buff *skb)
 452 {
 453         int i;
 454         int j;
 455         int rlen;
 456         int mlen;
 457         int olen;
 458         int size;
 459         int sval1;
 460         int sval2;
 461         int nframes;
 462         unsigned char *v110buf;
 463         unsigned char *rbuf;
 464         struct sk_buff *nskb;
 465
 466         if (v == NULL) {
 467                 /* invalid handle, no chance to proceed */
 468                 printk(KERN_WARNING "isdn_v110_encode called with NULL stream!\n");
 469                 return NULL;
 470         }
 471         if (!skb) {
 472                 /* invalid skb, no chance to proceed */
 473                 printk(KERN_WARNING "isdn_v110_encode called with NULL skb!\n");
 474                 return NULL;
 475         }
 476         rlen = skb->len;
 477         nframes = (rlen + 3) / 4;
 478         v110buf = v->encodebuf;
 479         if ((nframes * 40) > v->maxsize) {
 480                 size = v->maxsize;
 481                 rlen = v->maxsize / 40;
 482         } else
 483                 size = nframes * 40;
 484         if (!(nskb = dev_alloc_skb(size + v->skbres + sizeof(int)))) {
 485                 printk(KERN_WARNING "isdn_v110_encode: Couldn't alloc skb\n");
 486                 return NULL;
 487         }
 488         skb_reserve(nskb, v->skbres + sizeof(int));
 489         if (skb->len == 0) {
 490                 memcpy(skb_put(nskb, v->framelen), v->OnlineFrame, v->framelen);
 491                 *((int *)skb_push(nskb, sizeof(int))) = 0;
 492                 return nskb;
 493         }
 494         mlen = EncodeMatrix(skb->data, rlen, v110buf, size);
 495         /* now distribute 2 or 4 bits each to the output stream! */
 496         rbuf = skb_put(nskb, size);
 497         olen = 0;
 498         sval1 = 8 - v->nbits;
 499         sval2 = v->key << sval1;
 500         for (i = 0; i < mlen; i++) {
 501                 v110buf[i] = FlipBits(v110buf[i], v->nbits);
 502                 for (j = 0; j < v->nbytes; j++) {
 503                         if (size--)
 504                                 *rbuf++ = ~v->key | (((v110buf[i] << (j * v->nbits)) & sval2) >> sval1);
 505                         else {
 506                                 printk(KERN_WARNING "isdn_v110_encode: buffers full!\n");
 507                                 goto buffer_full;
 508                         }
 509                         olen++;
 510                 }
 511         }
 512 buffer_full:
 513         skb_trim(nskb, olen);
 514         *((int *)skb_push(nskb, sizeof(int))) = rlen;
 515         return nskb;
 516 }
 517
 518 int
 519 isdn_v110_stat_callback(int idx, isdn_ctrl *c)
 520 {
 521         isdn_v110_stream *v = NULL;
 522         int i;
 523         int ret = 0;
 524
 525         if (idx < 0)
 526                 return 0;
 527         switch (c->command) {
 528                 case ISDN_STAT_BSENT:
 529                         /* Keep the send-queue of the driver filled
 530                          * with frames:
 531                          * If number of outstanding frames < 3,
 532                          * send down an Idle-Frame (or an Sync-Frame, if
 533                          * v->SyncInit != 0).
 534                          */
 535                         if (!(v = dev->v110[idx]))
 536                                 return 0;
 537                         atomic_inc(&dev->v110use[idx]);
 538                         for (i=0; i * v->framelen < c->parm.length; i++) {
 539                                 if (v->skbidle > 0) {
 540                                         v->skbidle--;
 541                                         ret = 1;
 542                                 } else {
 543                                         if (v->skbuser > 0)
 544                                                 v->skbuser--;
 545                                         ret = 0;
 546                                 }
 547                         }
 548                         for (i = v->skbuser + v->skbidle; i < 2; i++) {
 549                                 struct sk_buff *skb;
 550                                 if (v->SyncInit > 0)
 551                                         skb = isdn_v110_sync(v);
 552                                 else
 553                                         skb = isdn_v110_idle(v);
 554                                 if (skb) {
 555                                         if (dev->drv[c->driver]->interface->writebuf_skb(c->driver, c->arg, 1, skb) <= 0) {
 556                                                 dev_kfree_skb(skb);
 557                                                 break;
 558                                         } else {
 559                                                 if (v->SyncInit)
 560                                                         v->SyncInit--;
 561                                                 v->skbidle++;
 562                                         }
 563                                 } else
 564                                         break;
 565                         }
 566                         atomic_dec(&dev->v110use[idx]);
 567                         return ret;
 568                 case ISDN_STAT_DHUP:
 569                 case ISDN_STAT_BHUP:
 570                         while (1) {
 571                                 atomic_inc(&dev->v110use[idx]);
 572                                 if (atomic_dec_and_test(&dev->v110use[idx])) {
 573                                         isdn_v110_close(dev->v110[idx]);
 574                                         dev->v110[idx] = NULL;
 575                                         break;
 576                                 }
 577                                 mdelay(1);
 578                         }
 579                         break;
 580                 case ISDN_STAT_BCONN:
 581                         if (dev->v110emu[idx] && (dev->v110[idx] == NULL)) {
 582                                 int hdrlen = dev->drv[c->driver]->interface->hl_hdrlen;
 583                                 int maxsize = dev->drv[c->driver]->interface->maxbufsize;
 584                                 atomic_inc(&dev->v110use[idx]);
 585                                 switch (dev->v110emu[idx]) {
 586                                         case ISDN_PROTO_L2_V11096:
 587                                                 dev->v110[idx] = isdn_v110_open(V110_9600, hdrlen, maxsize);
 588                                                 break;
 589                                         case ISDN_PROTO_L2_V11019:
 590                                                 dev->v110[idx] = isdn_v110_open(V110_19200, hdrlen, maxsize);
 591                                                 break;
 592                                         case ISDN_PROTO_L2_V11038:
 593                                                 dev->v110[idx] = isdn_v110_open(V110_38400, hdrlen, maxsize);
 594                                                 break;
 595                                         default:;
 596                                 }
 597                                 if ((v = dev->v110[idx])) {
 598                                         while (v->SyncInit) {
 599                                                 struct sk_buff *skb = isdn_v110_sync(v);
 600                                                 if (dev->drv[c->driver]->interface->writebuf_skb(c->driver, c->arg, 1, skb) <= 0) {
 601                                                         dev_kfree_skb(skb);
 602                                                         /* Unable to send, try later */
 603                                                         break;
 604                                                 }
 605                                                 v->SyncInit--;
 606                                                 v->skbidle++;
 607                                         }
 608                                 } else
 609                                         printk(KERN_WARNING "isdn_v110: Couldn't open stream for chan %d\n", idx);
 610                                 atomic_dec(&dev->v110use[idx]);
 611                         }
 612                         break;
 613                 default:
 614                         return 0;
 615         }
 616         return 0;
 617 }