drivers/char/rio/riotty.c

   1 /*
   2 ** -----------------------------------------------------------------------------
   3 **
   4 **  Perle Specialix driver for Linux
   5 **  Ported from existing RIO Driver for SCO sources.
   6  *
   7  *  (C) 1990 - 2000 Specialix International Ltd., Byfleet, Surrey, UK.
   8  *
   9  *      This program is free software; you can redistribute it and/or modify
  10  *      it under the terms of the GNU General Public License as published by
  11  *      the Free Software Foundation; either version 2 of the License, or
  12  *      (at your option) any later version.
  13  *
  14  *      This program is distributed in the hope that it will be useful,
  15  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *      GNU General Public License for more details.
  18  *
  19  *      You should have received a copy of the GNU General Public License
  20  *      along with this program; if not, write to the Free Software
  21  *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 **
  23 **      Module          : riotty.c
  24 **      SID             : 1.3
  25 **      Last Modified   : 11/6/98 10:33:47
  26 **      Retrieved       : 11/6/98 10:33:50
  27 **
  28 **  ident @(#)riotty.c  1.3
  29 **
  30 ** -----------------------------------------------------------------------------
  31 */
  32 #ifdef SCCS_LABELS
  33 static char *_riotty_c_sccs_ = "@(#)riotty.c    1.3";
  34 #endif
  35
  36
  37 #define __EXPLICIT_DEF_H__
  38
  39 #include <linux/module.h>
  40 #include <linux/slab.h>
  41 #include <linux/errno.h>
  42 #include <linux/tty.h>
  43 #include <linux/string.h>
  44 #include <asm/io.h>
  45 #include <asm/system.h>
  46 #include <asm/string.h>
  47 #include <asm/semaphore.h>
  48 #include <asm/uaccess.h>
  49
  50 #include <linux/termios.h>
  51
  52 #include <linux/serial.h>
  53
  54 #include <linux/generic_serial.h>
  55
  56
  57 #include "linux_compat.h"
  58 #include "rio_linux.h"
  59 #include "pkt.h"
  60 #include "daemon.h"
  61 #include "rio.h"
  62 #include "riospace.h"
  63 #include "cmdpkt.h"
  64 #include "map.h"
  65 #include "rup.h"
  66 #include "port.h"
  67 #include "riodrvr.h"
  68 #include "rioinfo.h"
  69 #include "func.h"
  70 #include "errors.h"
  71 #include "pci.h"
  72
  73 #include "parmmap.h"
  74 #include "unixrup.h"
  75 #include "board.h"
  76 #include "host.h"
  77 #include "phb.h"
  78 #include "link.h"
  79 #include "cmdblk.h"
  80 #include "route.h"
  81 #include "cirrus.h"
  82 #include "rioioctl.h"
  83 #include "param.h"
  84
  85 static void RIOClearUp(struct Port *PortP);
  86
  87 /* Below belongs in func.h */
  88 int RIOShortCommand(struct rio_info *p, struct Port *PortP, int command, int len, int arg);
  89
  90
  91 extern struct rio_info *p;
  92
  93
  94 int riotopen(struct tty_struct *tty, struct file *filp)
  95 {
  96         unsigned int SysPort;
  97         int repeat_this = 250;
  98         struct Port *PortP;     /* pointer to the port structure */
  99         unsigned long flags;
 100         int retval = 0;
 101
 102         func_enter();
 103
 104         /* Make sure driver_data is NULL in case the rio isn't booted jet. Else gs_close
 105            is going to oops.
 106          */
 107         tty->driver_data = NULL;
 108
 109         SysPort = rio_minor(tty);
 110
 111         if (p->RIOFailed) {
 112                 rio_dprintk(RIO_DEBUG_TTY, "System initialisation failed\n");
 113                 func_exit();
 114                 return -ENXIO;
 115         }
 116
 117         rio_dprintk(RIO_DEBUG_TTY, "port open SysPort %d (mapped:%d)\n", SysPort, p->RIOPortp[SysPort]->Mapped);
 118
 119         /*
 120          ** Validate that we have received a legitimate request.
 121          ** Currently, just check that we are opening a port on
 122          ** a host card that actually exists, and that the port
 123          ** has been mapped onto a host.
 124          */
 125         if (SysPort >= RIO_PORTS) {     /* out of range ? */
 126                 rio_dprintk(RIO_DEBUG_TTY, "Illegal port number %d\n", SysPort);
 127                 func_exit();
 128                 return -ENXIO;
 129         }
 130
 131         /*
 132          ** Grab pointer to the port stucture
 133          */
 134         PortP = p->RIOPortp[SysPort];   /* Get control struc */
 135         rio_dprintk(RIO_DEBUG_TTY, "PortP: %p\n", PortP);
 136         if (!PortP->Mapped) {   /* we aren't mapped yet! */
 137                 /*
 138                  ** The system doesn't know which RTA this port
 139                  ** corresponds to.
 140                  */
 141                 rio_dprintk(RIO_DEBUG_TTY, "port not mapped into system\n");
 142                 func_exit();
 143                 return -ENXIO;
 144         }
 145
 146         tty->driver_data = PortP;
 147
 148         PortP->gs.tty = tty;
 149         PortP->gs.count++;
 150
 151         rio_dprintk(RIO_DEBUG_TTY, "%d bytes in tx buffer\n", PortP->gs.xmit_cnt);
 152
 153         retval = gs_init_port(&PortP->gs);
 154         if (retval) {
 155                 PortP->gs.count--;
 156                 return -ENXIO;
 157         }
 158         /*
 159          ** If the host hasn't been booted yet, then
 160          ** fail
 161          */
 162         if ((PortP->HostP->Flags & RUN_STATE) != RC_RUNNING) {
 163                 rio_dprintk(RIO_DEBUG_TTY, "Host not running\n");
 164                 func_exit();
 165                 return -ENXIO;
 166         }
 167
 168         /*
 169          ** If the RTA has not booted yet and the user has choosen to block
 170          ** until the RTA is present then we must spin here waiting for
 171          ** the RTA to boot.
 172          */
 173         /* I find the above code a bit hairy. I find the below code
 174            easier to read and shorter. Now, if it works too that would
 175            be great... -- REW
 176          */
 177         rio_dprintk(RIO_DEBUG_TTY, "Checking if RTA has booted... \n");
 178         while (!(PortP->HostP->Mapping[PortP->RupNum].Flags & RTA_BOOTED)) {
 179                 if (!PortP->WaitUntilBooted) {
 180                         rio_dprintk(RIO_DEBUG_TTY, "RTA never booted\n");
 181                         func_exit();
 182                         return -ENXIO;
 183                 }
 184
 185                 /* Under Linux you'd normally use a wait instead of this
 186                    busy-waiting. I'll stick with the old implementation for
 187                    now. --REW
 188                  */
 189                 if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 190                         rio_dprintk(RIO_DEBUG_TTY, "RTA_wait_for_boot: EINTR in delay \n");
 191                         func_exit();
 192                         return -EINTR;
 193                 }
 194                 if (repeat_this-- <= 0) {
 195                         rio_dprintk(RIO_DEBUG_TTY, "Waiting for RTA to boot timeout\n");
 196                         func_exit();
 197                         return -EIO;
 198                 }
 199         }
 200         rio_dprintk(RIO_DEBUG_TTY, "RTA has been booted\n");
 201         rio_spin_lock_irqsave(&PortP->portSem, flags);
 202         if (p->RIOHalted) {
 203                 goto bombout;
 204         }
 205
 206         /*
 207          ** If the port is in the final throws of being closed,
 208          ** we should wait here (politely), waiting
 209          ** for it to finish, so that it doesn't close us!
 210          */
 211         while ((PortP->State & RIO_CLOSING) && !p->RIOHalted) {
 212                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for RIO_CLOSING to go away\n");
 213                 if (repeat_this-- <= 0) {
 214                         rio_dprintk(RIO_DEBUG_TTY, "Waiting for not idle closed broken by signal\n");
 215                         RIOPreemptiveCmd(p, PortP, FCLOSE);
 216                         retval = -EINTR;
 217                         goto bombout;
 218                 }
 219                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 220                 if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 221                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 222                         retval = -EINTR;
 223                         goto bombout;
 224                 }
 225                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 226         }
 227
 228         if (!PortP->Mapped) {
 229                 rio_dprintk(RIO_DEBUG_TTY, "Port unmapped while closing!\n");
 230                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 231                 retval = -ENXIO;
 232                 func_exit();
 233                 return retval;
 234         }
 235
 236         if (p->RIOHalted) {
 237                 goto bombout;
 238         }
 239
 240 /*
 241 ** 15.10.1998 ARG - ESIL 0761 part fix
 242 ** RIO has it's own CTSFLOW and RTSFLOW flags in 'Config' in the port structure,
 243 ** we need to make sure that the flags are clear when the port is opened.
 244 */
 245         /* Uh? Suppose I turn these on and then another process opens
 246            the port again? The flags get cleared! Not good. -- REW */
 247         if (!(PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
 248                 PortP->Config &= ~(RIO_CTSFLOW | RIO_RTSFLOW);
 249         }
 250
 251         if (!(PortP->firstOpen)) {      /* First time ? */
 252                 rio_dprintk(RIO_DEBUG_TTY, "First open for this port\n");
 253
 254
 255                 PortP->firstOpen++;
 256                 PortP->CookMode = 0;    /* XXX RIOCookMode(tp); */
 257                 PortP->InUse = NOT_INUSE;
 258
 259                 /* Tentative fix for bug PR27. Didn't work. */
 260                 /* PortP->gs.xmit_cnt = 0; */
 261
 262                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 263
 264                 /* Someone explain to me why this delay/config is
 265                    here. If I read the docs correctly the "open"
 266                    command piggybacks the parameters immediately.
 267                    -- REW */
 268                 RIOParam(PortP, OPEN, 1, OK_TO_SLEEP);  /* Open the port */
 269                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 270
 271                 /*
 272                  ** wait for the port to be not closed.
 273                  */
 274                 while (!(PortP->PortState & PORT_ISOPEN) && !p->RIOHalted) {
 275                         rio_dprintk(RIO_DEBUG_TTY, "Waiting for PORT_ISOPEN-currently %x\n", PortP->PortState);
 276                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 277                         if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 278                                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for open to finish broken by signal\n");
 279                                 RIOPreemptiveCmd(p, PortP, FCLOSE);
 280                                 func_exit();
 281                                 return -EINTR;
 282                         }
 283                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 284                 }
 285
 286                 if (p->RIOHalted) {
 287                         retval = -EIO;
 288                       bombout:
 289                         /*                    RIOClearUp( PortP ); */
 290                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 291                         return retval;
 292                 }
 293                 rio_dprintk(RIO_DEBUG_TTY, "PORT_ISOPEN found\n");
 294         }
 295         rio_dprintk(RIO_DEBUG_TTY, "Modem - test for carrier\n");
 296         /*
 297          ** ACTION
 298          ** insert test for carrier here. -- ???
 299          ** I already see that test here. What's the deal? -- REW
 300          */
 301         if ((PortP->gs.tty->termios->c_cflag & CLOCAL) || (PortP->ModemState & MSVR1_CD)) {
 302                 rio_dprintk(RIO_DEBUG_TTY, "open(%d) Modem carr on\n", SysPort);
 303                 /*
 304                    tp->tm.c_state |= CARR_ON;
 305                    wakeup((caddr_t) &tp->tm.c_canq);
 306                  */
 307                 PortP->State |= RIO_CARR_ON;
 308                 wake_up_interruptible(&PortP->gs.open_wait);
 309         } else {        /* no carrier - wait for DCD */
 310                         /*
 311                    while (!(PortP->gs.tty->termios->c_state & CARR_ON) &&
 312                    !(filp->f_flags & O_NONBLOCK) && !p->RIOHalted )
 313                  */
 314                 while (!(PortP->State & RIO_CARR_ON) && !(filp->f_flags & O_NONBLOCK) && !p->RIOHalted) {
 315                                 rio_dprintk(RIO_DEBUG_TTY, "open(%d) sleeping for carr on\n", SysPort);
 316                         /*
 317                            PortP->gs.tty->termios->c_state |= WOPEN;
 318                          */
 319                         PortP->State |= RIO_WOPEN;
 320                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 321                         if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 322                                 /*
 323                                  ** ACTION: verify that this is a good thing
 324                                  ** to do here. -- ???
 325                                  ** I think it's OK. -- REW
 326                                  */
 327                                 rio_dprintk(RIO_DEBUG_TTY, "open(%d) sleeping for carr broken by signal\n", SysPort);
 328                                 RIOPreemptiveCmd(p, PortP, FCLOSE);
 329                                 /*
 330                                    tp->tm.c_state &= ~WOPEN;
 331                                  */
 332                                 PortP->State &= ~RIO_WOPEN;
 333                                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 334                                 func_exit();
 335                                 return -EINTR;
 336                         }
 337                 }
 338                 PortP->State &= ~RIO_WOPEN;
 339         }
 340         if (p->RIOHalted)
 341                 goto bombout;
 342         rio_dprintk(RIO_DEBUG_TTY, "Setting RIO_MOPEN\n");
 343         PortP->State |= RIO_MOPEN;
 344
 345         if (p->RIOHalted)
 346                 goto bombout;
 347
 348         rio_dprintk(RIO_DEBUG_TTY, "high level open done\n");
 349
 350         /*
 351          ** Count opens for port statistics reporting
 352          */
 353         if (PortP->statsGather)
 354                 PortP->opens++;
 355
 356         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 357         rio_dprintk(RIO_DEBUG_TTY, "Returning from open\n");
 358         func_exit();
 359         return 0;
 360 }
 361
 362 /*
 363 ** RIOClose the port.
 364 ** The operating system thinks that this is last close for the device.
 365 ** As there are two interfaces to the port (Modem and tty), we need to
 366 ** check that both are closed before we close the device.
 367 */
 368 int riotclose(void *ptr)
 369 {
 370         struct Port *PortP = ptr;       /* pointer to the port structure */
 371         int deleted = 0;
 372         int try = -1;           /* Disable the timeouts by setting them to -1 */
 373         int repeat_this = -1;   /* Congrats to those having 15 years of
 374                                    uptime! (You get to break the driver.) */
 375         unsigned long end_time;
 376         struct tty_struct *tty;
 377         unsigned long flags;
 378         int rv = 0;
 379
 380         rio_dprintk(RIO_DEBUG_TTY, "port close SysPort %d\n", PortP->PortNum);
 381
 382         /* PortP = p->RIOPortp[SysPort]; */
 383         rio_dprintk(RIO_DEBUG_TTY, "Port is at address %p\n", PortP);
 384         /* tp = PortP->TtyP; *//* Get tty */
 385         tty = PortP->gs.tty;
 386         rio_dprintk(RIO_DEBUG_TTY, "TTY is at address %p\n", tty);
 387
 388         if (PortP->gs.closing_wait)
 389                 end_time = jiffies + PortP->gs.closing_wait;
 390         else
 391                 end_time = jiffies + MAX_SCHEDULE_TIMEOUT;
 392
 393         rio_spin_lock_irqsave(&PortP->portSem, flags);
 394
 395         /*
 396          ** Setting this flag will make any process trying to open
 397          ** this port block until we are complete closing it.
 398          */
 399         PortP->State |= RIO_CLOSING;
 400
 401         if ((PortP->State & RIO_DELETED)) {
 402                 rio_dprintk(RIO_DEBUG_TTY, "Close on deleted RTA\n");
 403                 deleted = 1;
 404         }
 405
 406         if (p->RIOHalted) {
 407                 RIOClearUp(PortP);
 408                 rv = -EIO;
 409                 goto close_end;
 410         }
 411
 412         rio_dprintk(RIO_DEBUG_TTY, "Clear bits\n");
 413         /*
 414          ** clear the open bits for this device
 415          */
 416         PortP->State &= ~RIO_MOPEN;
 417         PortP->State &= ~RIO_CARR_ON;
 418         PortP->ModemState &= ~MSVR1_CD;
 419         /*
 420          ** If the device was open as both a Modem and a tty line
 421          ** then we need to wimp out here, as the port has not really
 422          ** been finally closed (gee, whizz!) The test here uses the
 423          ** bit for the OTHER mode of operation, to see if THAT is
 424          ** still active!
 425          */
 426         if ((PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
 427                 /*
 428                  ** The port is still open for the other task -
 429                  ** return, pretending that we are still active.
 430                  */
 431                 rio_dprintk(RIO_DEBUG_TTY, "Channel %d still open !\n", PortP->PortNum);
 432                 PortP->State &= ~RIO_CLOSING;
 433                 if (PortP->firstOpen)
 434                         PortP->firstOpen--;
 435                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 436                 return -EIO;
 437         }
 438
 439         rio_dprintk(RIO_DEBUG_TTY, "Closing down - everything must go!\n");
 440
 441         PortP->State &= ~RIO_DYNOROD;
 442
 443         /*
 444          ** This is where we wait for the port
 445          ** to drain down before closing. Bye-bye....
 446          ** (We never meant to do this)
 447          */
 448         rio_dprintk(RIO_DEBUG_TTY, "Timeout 1 starts\n");
 449
 450         if (!deleted)
 451                 while ((PortP->InUse != NOT_INUSE) && !p->RIOHalted && (PortP->TxBufferIn != PortP->TxBufferOut)) {
 452                         if (repeat_this-- <= 0) {
 453                                 rv = -EINTR;
 454                                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for not idle closed broken by signal\n");
 455                                 RIOPreemptiveCmd(p, PortP, FCLOSE);
 456                                 goto close_end;
 457                         }
 458                         rio_dprintk(RIO_DEBUG_TTY, "Calling timeout to flush in closing\n");
 459                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 460                         if (RIODelay_ni(PortP, HUNDRED_MS * 10) == RIO_FAIL) {
 461                                 rio_dprintk(RIO_DEBUG_TTY, "RTA EINTR in delay \n");
 462                                 rv = -EINTR;
 463                                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 464                                 goto close_end;
 465                         }
 466                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 467                 }
 468
 469         PortP->TxBufferIn = PortP->TxBufferOut = 0;
 470         repeat_this = 0xff;
 471
 472         PortP->InUse = 0;
 473         if ((PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
 474                 /*
 475                  ** The port has been re-opened for the other task -
 476                  ** return, pretending that we are still active.
 477                  */
 478                 rio_dprintk(RIO_DEBUG_TTY, "Channel %d re-open!\n", PortP->PortNum);
 479                 PortP->State &= ~RIO_CLOSING;
 480                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 481                 if (PortP->firstOpen)
 482                         PortP->firstOpen--;
 483                 return -EIO;
 484         }
 485
 486         if (p->RIOHalted) {
 487                 RIOClearUp(PortP);
 488                 goto close_end;
 489         }
 490
 491         /* Can't call RIOShortCommand with the port locked. */
 492         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 493
 494         if (RIOShortCommand(p, PortP, CLOSE, 1, 0) == RIO_FAIL) {
 495                 RIOPreemptiveCmd(p, PortP, FCLOSE);
 496                 goto close_end;
 497         }
 498
 499         if (!deleted)
 500                 while (try && (PortP->PortState & PORT_ISOPEN)) {
 501                         try--;
 502                         if (time_after(jiffies, end_time)) {
 503                                 rio_dprintk(RIO_DEBUG_TTY, "Run out of tries - force the bugger shut!\n");
 504                                 RIOPreemptiveCmd(p, PortP, FCLOSE);
 505                                 break;
 506                         }
 507                         rio_dprintk(RIO_DEBUG_TTY, "Close: PortState:ISOPEN is %d\n", PortP->PortState & PORT_ISOPEN);
 508
 509                         if (p->RIOHalted) {
 510                                 RIOClearUp(PortP);
 511                                 goto close_end;
 512                         }
 513                         if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 514                                 rio_dprintk(RIO_DEBUG_TTY, "RTA EINTR in delay \n");
 515                                 RIOPreemptiveCmd(p, PortP, FCLOSE);
 516                                 break;
 517                         }
 518                 }
 519         rio_spin_lock_irqsave(&PortP->portSem, flags);
 520         rio_dprintk(RIO_DEBUG_TTY, "Close: try was %d on completion\n", try);
 521
 522         /* RIOPreemptiveCmd(p, PortP, FCLOSE); */
 523
 524 /*
 525 ** 15.10.1998 ARG - ESIL 0761 part fix
 526 ** RIO has it's own CTSFLOW and RTSFLOW flags in 'Config' in the port structure,** we need to make sure that the flags are clear when the port is opened.
 527 */
 528         PortP->Config &= ~(RIO_CTSFLOW | RIO_RTSFLOW);
 529
 530         /*
 531          ** Count opens for port statistics reporting
 532          */
 533         if (PortP->statsGather)
 534                 PortP->closes++;
 535
 536 close_end:
 537         /* XXX: Why would a "DELETED" flag be reset here? I'd have
 538            thought that a "deleted" flag means that the port was
 539            permanently gone, but here we can make it reappear by it
 540            being in close during the "deletion".
 541          */
 542         PortP->State &= ~(RIO_CLOSING | RIO_DELETED);
 543         if (PortP->firstOpen)
 544                 PortP->firstOpen--;
 545         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 546         rio_dprintk(RIO_DEBUG_TTY, "Return from close\n");
 547         return rv;
 548 }
 549
 550
 551
 552 static void RIOClearUp(struct Port *PortP)
 553 {
 554         rio_dprintk(RIO_DEBUG_TTY, "RIOHalted set\n");
 555         PortP->Config = 0;      /* Direct semaphore */
 556         PortP->PortState = 0;
 557         PortP->firstOpen = 0;
 558         PortP->FlushCmdBodge = 0;
 559         PortP->ModemState = PortP->CookMode = 0;
 560         PortP->Mapped = 0;
 561         PortP->WflushFlag = 0;
 562         PortP->MagicFlags = 0;
 563         PortP->RxDataStart = 0;
 564         PortP->TxBufferIn = 0;
 565         PortP->TxBufferOut = 0;
 566 }
 567
 568 /*
 569 ** Put a command onto a port.
 570 ** The PortPointer, command, length and arg are passed.
 571 ** The len is the length *inclusive* of the command byte,
 572 ** and so for a command that takes no data, len==1.
 573 ** The arg is a single byte, and is only used if len==2.
 574 ** Other values of len aren't allowed, and will cause
 575 ** a panic.
 576 */
 577 int RIOShortCommand(struct rio_info *p, struct Port *PortP, int command, int len, int arg)
 578 {
 579         struct PKT __iomem *PacketP;
 580         int retries = 20;       /* at 10 per second -> 2 seconds */
 581         unsigned long flags;
 582
 583         rio_dprintk(RIO_DEBUG_TTY, "entering shortcommand.\n");
 584
 585         if (PortP->State & RIO_DELETED) {
 586                 rio_dprintk(RIO_DEBUG_TTY, "Short command to deleted RTA ignored\n");
 587                 return RIO_FAIL;
 588         }
 589         rio_spin_lock_irqsave(&PortP->portSem, flags);
 590
 591         /*
 592          ** If the port is in use for pre-emptive command, then wait for it to
 593          ** be free again.
 594          */
 595         while ((PortP->InUse != NOT_INUSE) && !p->RIOHalted) {
 596                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for not in use (%d)\n", retries);
 597                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 598                 if (retries-- <= 0) {
 599                         return RIO_FAIL;
 600                 }
 601                 if (RIODelay_ni(PortP, HUNDRED_MS) == RIO_FAIL) {
 602                         return RIO_FAIL;
 603                 }
 604                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 605         }
 606         if (PortP->State & RIO_DELETED) {
 607                 rio_dprintk(RIO_DEBUG_TTY, "Short command to deleted RTA ignored\n");
 608                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 609                 return RIO_FAIL;
 610         }
 611
 612         while (!can_add_transmit(&PacketP, PortP) && !p->RIOHalted) {
 613                 rio_dprintk(RIO_DEBUG_TTY, "Waiting to add short command to queue (%d)\n", retries);
 614                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 615                 if (retries-- <= 0) {
 616                         rio_dprintk(RIO_DEBUG_TTY, "out of tries. Failing\n");
 617                         return RIO_FAIL;
 618                 }
 619                 if (RIODelay_ni(PortP, HUNDRED_MS) == RIO_FAIL) {
 620                         return RIO_FAIL;
 621                 }
 622                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 623         }
 624
 625         if (p->RIOHalted) {
 626                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 627                 return RIO_FAIL;
 628         }
 629
 630         /*
 631          ** set the command byte and the argument byte
 632          */
 633         writeb(command, &PacketP->data[0]);
 634
 635         if (len == 2)
 636                 writeb(arg, &PacketP->data[1]);
 637
 638         /*
 639          ** set the length of the packet and set the command bit.
 640          */
 641         writeb(PKT_CMD_BIT | len, &PacketP->len);
 642
 643         add_transmit(PortP);
 644         /*
 645          ** Count characters transmitted for port statistics reporting
 646          */
 647         if (PortP->statsGather)
 648                 PortP->txchars += len;
 649
 650         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 651         return p->RIOHalted ? RIO_FAIL : ~RIO_FAIL;
 652 }
 653
 654