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
  33 #define __EXPLICIT_DEF_H__
  34
  35 #include <linux/module.h>
  36 #include <linux/sched.h>
  37 #include <linux/slab.h>
  38 #include <linux/errno.h>
  39 #include <linux/tty.h>
  40 #include <linux/string.h>
  41 #include <asm/io.h>
  42 #include <asm/system.h>
  43 #include <asm/string.h>
  44 #include <asm/uaccess.h>
  45
  46 #include <linux/termios.h>
  47
  48 #include <linux/serial.h>
  49
  50 #include <linux/generic_serial.h>
  51
  52
  53 #include "linux_compat.h"
  54 #include "rio_linux.h"
  55 #include "pkt.h"
  56 #include "daemon.h"
  57 #include "rio.h"
  58 #include "riospace.h"
  59 #include "cmdpkt.h"
  60 #include "map.h"
  61 #include "rup.h"
  62 #include "port.h"
  63 #include "riodrvr.h"
  64 #include "rioinfo.h"
  65 #include "func.h"
  66 #include "errors.h"
  67 #include "pci.h"
  68
  69 #include "parmmap.h"
  70 #include "unixrup.h"
  71 #include "board.h"
  72 #include "host.h"
  73 #include "phb.h"
  74 #include "link.h"
  75 #include "cmdblk.h"
  76 #include "route.h"
  77 #include "cirrus.h"
  78 #include "rioioctl.h"
  79 #include "param.h"
  80
  81 static void RIOClearUp(struct Port *PortP);
  82
  83 /* Below belongs in func.h */
  84 int RIOShortCommand(struct rio_info *p, struct Port *PortP, int command, int len, int arg);
  85
  86
  87 extern struct rio_info *p;
  88
  89
  90 int riotopen(struct tty_struct *tty, struct file *filp)
  91 {
  92         unsigned int SysPort;
  93         int repeat_this = 250;
  94         struct Port *PortP;     /* pointer to the port structure */
  95         unsigned long flags;
  96         int retval = 0;
  97
  98         func_enter();
  99
 100         /* Make sure driver_data is NULL in case the rio isn't booted jet. Else gs_close
 101            is going to oops.
 102          */
 103         tty->driver_data = NULL;
 104
 105         SysPort = rio_minor(tty);
 106
 107         if (p->RIOFailed) {
 108                 rio_dprintk(RIO_DEBUG_TTY, "System initialisation failed\n");
 109                 func_exit();
 110                 return -ENXIO;
 111         }
 112
 113         rio_dprintk(RIO_DEBUG_TTY, "port open SysPort %d (mapped:%d)\n", SysPort, p->RIOPortp[SysPort]->Mapped);
 114
 115         /*
 116          ** Validate that we have received a legitimate request.
 117          ** Currently, just check that we are opening a port on
 118          ** a host card that actually exists, and that the port
 119          ** has been mapped onto a host.
 120          */
 121         if (SysPort >= RIO_PORTS) {     /* out of range ? */
 122                 rio_dprintk(RIO_DEBUG_TTY, "Illegal port number %d\n", SysPort);
 123                 func_exit();
 124                 return -ENXIO;
 125         }
 126
 127         /*
 128          ** Grab pointer to the port stucture
 129          */
 130         PortP = p->RIOPortp[SysPort];   /* Get control struc */
 131         rio_dprintk(RIO_DEBUG_TTY, "PortP: %p\n", PortP);
 132         if (!PortP->Mapped) {   /* we aren't mapped yet! */
 133                 /*
 134                  ** The system doesn't know which RTA this port
 135                  ** corresponds to.
 136                  */
 137                 rio_dprintk(RIO_DEBUG_TTY, "port not mapped into system\n");
 138                 func_exit();
 139                 return -ENXIO;
 140         }
 141
 142         tty->driver_data = PortP;
 143
 144         PortP->gs.port.tty = tty;
 145         PortP->gs.port.count++;
 146
 147         rio_dprintk(RIO_DEBUG_TTY, "%d bytes in tx buffer\n", PortP->gs.xmit_cnt);
 148
 149         retval = gs_init_port(&PortP->gs);
 150         if (retval) {
 151                 PortP->gs.port.count--;
 152                 return -ENXIO;
 153         }
 154         /*
 155          ** If the host hasn't been booted yet, then
 156          ** fail
 157          */
 158         if ((PortP->HostP->Flags & RUN_STATE) != RC_RUNNING) {
 159                 rio_dprintk(RIO_DEBUG_TTY, "Host not running\n");
 160                 func_exit();
 161                 return -ENXIO;
 162         }
 163
 164         /*
 165          ** If the RTA has not booted yet and the user has choosen to block
 166          ** until the RTA is present then we must spin here waiting for
 167          ** the RTA to boot.
 168          */
 169         /* I find the above code a bit hairy. I find the below code
 170            easier to read and shorter. Now, if it works too that would
 171            be great... -- REW
 172          */
 173         rio_dprintk(RIO_DEBUG_TTY, "Checking if RTA has booted... \n");
 174         while (!(PortP->HostP->Mapping[PortP->RupNum].Flags & RTA_BOOTED)) {
 175                 if (!PortP->WaitUntilBooted) {
 176                         rio_dprintk(RIO_DEBUG_TTY, "RTA never booted\n");
 177                         func_exit();
 178                         return -ENXIO;
 179                 }
 180
 181                 /* Under Linux you'd normally use a wait instead of this
 182                    busy-waiting. I'll stick with the old implementation for
 183                    now. --REW
 184                  */
 185                 if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 186                         rio_dprintk(RIO_DEBUG_TTY, "RTA_wait_for_boot: EINTR in delay \n");
 187                         func_exit();
 188                         return -EINTR;
 189                 }
 190                 if (repeat_this-- <= 0) {
 191                         rio_dprintk(RIO_DEBUG_TTY, "Waiting for RTA to boot timeout\n");
 192                         func_exit();
 193                         return -EIO;
 194                 }
 195         }
 196         rio_dprintk(RIO_DEBUG_TTY, "RTA has been booted\n");
 197         rio_spin_lock_irqsave(&PortP->portSem, flags);
 198         if (p->RIOHalted) {
 199                 goto bombout;
 200         }
 201
 202         /*
 203          ** If the port is in the final throws of being closed,
 204          ** we should wait here (politely), waiting
 205          ** for it to finish, so that it doesn't close us!
 206          */
 207         while ((PortP->State & RIO_CLOSING) && !p->RIOHalted) {
 208                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for RIO_CLOSING to go away\n");
 209                 if (repeat_this-- <= 0) {
 210                         rio_dprintk(RIO_DEBUG_TTY, "Waiting for not idle closed broken by signal\n");
 211                         RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 212                         retval = -EINTR;
 213                         goto bombout;
 214                 }
 215                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 216                 if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 217                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 218                         retval = -EINTR;
 219                         goto bombout;
 220                 }
 221                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 222         }
 223
 224         if (!PortP->Mapped) {
 225                 rio_dprintk(RIO_DEBUG_TTY, "Port unmapped while closing!\n");
 226                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 227                 retval = -ENXIO;
 228                 func_exit();
 229                 return retval;
 230         }
 231
 232         if (p->RIOHalted) {
 233                 goto bombout;
 234         }
 235
 236 /*
 237 ** 15.10.1998 ARG - ESIL 0761 part fix
 238 ** RIO has it's own CTSFLOW and RTSFLOW flags in 'Config' in the port structure,
 239 ** we need to make sure that the flags are clear when the port is opened.
 240 */
 241         /* Uh? Suppose I turn these on and then another process opens
 242            the port again? The flags get cleared! Not good. -- REW */
 243         if (!(PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
 244                 PortP->Config &= ~(RIO_CTSFLOW | RIO_RTSFLOW);
 245         }
 246
 247         if (!(PortP->firstOpen)) {      /* First time ? */
 248                 rio_dprintk(RIO_DEBUG_TTY, "First open for this port\n");
 249
 250
 251                 PortP->firstOpen++;
 252                 PortP->CookMode = 0;    /* XXX RIOCookMode(tp); */
 253                 PortP->InUse = NOT_INUSE;
 254
 255                 /* Tentative fix for bug PR27. Didn't work. */
 256                 /* PortP->gs.xmit_cnt = 0; */
 257
 258                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 259
 260                 /* Someone explain to me why this delay/config is
 261                    here. If I read the docs correctly the "open"
 262                    command piggybacks the parameters immediately.
 263                    -- REW */
 264                 RIOParam(PortP, RIOC_OPEN, 1, OK_TO_SLEEP); /* Open the port */
 265                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 266
 267                 /*
 268                  ** wait for the port to be not closed.
 269                  */
 270                 while (!(PortP->PortState & PORT_ISOPEN) && !p->RIOHalted) {
 271                         rio_dprintk(RIO_DEBUG_TTY, "Waiting for PORT_ISOPEN-currently %x\n", PortP->PortState);
 272                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 273                         if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 274                                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for open to finish broken by signal\n");
 275                                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 276                                 func_exit();
 277                                 return -EINTR;
 278                         }
 279                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 280                 }
 281
 282                 if (p->RIOHalted) {
 283                         retval = -EIO;
 284                       bombout:
 285                         /*                    RIOClearUp( PortP ); */
 286                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 287                         return retval;
 288                 }
 289                 rio_dprintk(RIO_DEBUG_TTY, "PORT_ISOPEN found\n");
 290         }
 291         rio_dprintk(RIO_DEBUG_TTY, "Modem - test for carrier\n");
 292         /*
 293          ** ACTION
 294          ** insert test for carrier here. -- ???
 295          ** I already see that test here. What's the deal? -- REW
 296          */
 297         if ((PortP->gs.port.tty->termios->c_cflag & CLOCAL) ||
 298                         (PortP->ModemState & RIOC_MSVR1_CD)) {
 299                 rio_dprintk(RIO_DEBUG_TTY, "open(%d) Modem carr on\n", SysPort);
 300                 /*
 301                    tp->tm.c_state |= CARR_ON;
 302                    wakeup((caddr_t) &tp->tm.c_canq);
 303                  */
 304                 PortP->State |= RIO_CARR_ON;
 305                 wake_up_interruptible(&PortP->gs.port.open_wait);
 306         } else {        /* no carrier - wait for DCD */
 307                         /*
 308                    while (!(PortP->gs.port.tty->termios->c_state & CARR_ON) &&
 309                    !(filp->f_flags & O_NONBLOCK) && !p->RIOHalted )
 310                  */
 311                 while (!(PortP->State & RIO_CARR_ON) && !(filp->f_flags & O_NONBLOCK) && !p->RIOHalted) {
 312                                 rio_dprintk(RIO_DEBUG_TTY, "open(%d) sleeping for carr on\n", SysPort);
 313                         /*
 314                            PortP->gs.port.tty->termios->c_state |= WOPEN;
 315                          */
 316                         PortP->State |= RIO_WOPEN;
 317                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 318                         if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 319                                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 320                                 /*
 321                                  ** ACTION: verify that this is a good thing
 322                                  ** to do here. -- ???
 323                                  ** I think it's OK. -- REW
 324                                  */
 325                                 rio_dprintk(RIO_DEBUG_TTY, "open(%d) sleeping for carr broken by signal\n", SysPort);
 326                                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 327                                 /*
 328                                    tp->tm.c_state &= ~WOPEN;
 329                                  */
 330                                 PortP->State &= ~RIO_WOPEN;
 331                                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 332                                 func_exit();
 333                                 return -EINTR;
 334                         }
 335                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 336                 }
 337                 PortP->State &= ~RIO_WOPEN;
 338         }
 339         if (p->RIOHalted)
 340                 goto bombout;
 341         rio_dprintk(RIO_DEBUG_TTY, "Setting RIO_MOPEN\n");
 342         PortP->State |= RIO_MOPEN;
 343
 344         if (p->RIOHalted)
 345                 goto bombout;
 346
 347         rio_dprintk(RIO_DEBUG_TTY, "high level open done\n");
 348
 349         /*
 350          ** Count opens for port statistics reporting
 351          */
 352         if (PortP->statsGather)
 353                 PortP->opens++;
 354
 355         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 356         rio_dprintk(RIO_DEBUG_TTY, "Returning from open\n");
 357         func_exit();
 358         return 0;
 359 }
 360
 361 /*
 362 ** RIOClose the port.
 363 ** The operating system thinks that this is last close for the device.
 364 ** As there are two interfaces to the port (Modem and tty), we need to
 365 ** check that both are closed before we close the device.
 366 */
 367 int riotclose(void *ptr)
 368 {
 369         struct Port *PortP = ptr;       /* pointer to the port structure */
 370         int deleted = 0;
 371         int try = -1;           /* Disable the timeouts by setting them to -1 */
 372         int repeat_this = -1;   /* Congrats to those having 15 years of
 373                                    uptime! (You get to break the driver.) */
 374         unsigned long end_time;
 375         struct tty_struct *tty;
 376         unsigned long flags;
 377         int rv = 0;
 378
 379         rio_dprintk(RIO_DEBUG_TTY, "port close SysPort %d\n", PortP->PortNum);
 380
 381         /* PortP = p->RIOPortp[SysPort]; */
 382         rio_dprintk(RIO_DEBUG_TTY, "Port is at address %p\n", PortP);
 383         /* tp = PortP->TtyP; *//* Get tty */
 384         tty = PortP->gs.port.tty;
 385         rio_dprintk(RIO_DEBUG_TTY, "TTY is at address %p\n", tty);
 386
 387         if (PortP->gs.closing_wait)
 388                 end_time = jiffies + PortP->gs.closing_wait;
 389         else
 390                 end_time = jiffies + MAX_SCHEDULE_TIMEOUT;
 391
 392         rio_spin_lock_irqsave(&PortP->portSem, flags);
 393
 394         /*
 395          ** Setting this flag will make any process trying to open
 396          ** this port block until we are complete closing it.
 397          */
 398         PortP->State |= RIO_CLOSING;
 399
 400         if ((PortP->State & RIO_DELETED)) {
 401                 rio_dprintk(RIO_DEBUG_TTY, "Close on deleted RTA\n");
 402                 deleted = 1;
 403         }
 404
 405         if (p->RIOHalted) {
 406                 RIOClearUp(PortP);
 407                 rv = -EIO;
 408                 goto close_end;
 409         }
 410
 411         rio_dprintk(RIO_DEBUG_TTY, "Clear bits\n");
 412         /*
 413          ** clear the open bits for this device
 414          */
 415         PortP->State &= ~RIO_MOPEN;
 416         PortP->State &= ~RIO_CARR_ON;
 417         PortP->ModemState &= ~RIOC_MSVR1_CD;
 418         /*
 419          ** If the device was open as both a Modem and a tty line
 420          ** then we need to wimp out here, as the port has not really
 421          ** been finally closed (gee, whizz!) The test here uses the
 422          ** bit for the OTHER mode of operation, to see if THAT is
 423          ** still active!
 424          */
 425         if ((PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
 426                 /*
 427                  ** The port is still open for the other task -
 428                  ** return, pretending that we are still active.
 429                  */
 430                 rio_dprintk(RIO_DEBUG_TTY, "Channel %d still open !\n", PortP->PortNum);
 431                 PortP->State &= ~RIO_CLOSING;
 432                 if (PortP->firstOpen)
 433                         PortP->firstOpen--;
 434                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 435                 return -EIO;
 436         }
 437
 438         rio_dprintk(RIO_DEBUG_TTY, "Closing down - everything must go!\n");
 439
 440         PortP->State &= ~RIO_DYNOROD;
 441
 442         /*
 443          ** This is where we wait for the port
 444          ** to drain down before closing. Bye-bye....
 445          ** (We never meant to do this)
 446          */
 447         rio_dprintk(RIO_DEBUG_TTY, "Timeout 1 starts\n");
 448
 449         if (!deleted)
 450                 while ((PortP->InUse != NOT_INUSE) && !p->RIOHalted && (PortP->TxBufferIn != PortP->TxBufferOut)) {
 451                         if (repeat_this-- <= 0) {
 452                                 rv = -EINTR;
 453                                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for not idle closed broken by signal\n");
 454                                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 455                                 goto close_end;
 456                         }
 457                         rio_dprintk(RIO_DEBUG_TTY, "Calling timeout to flush in closing\n");
 458                         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 459                         if (RIODelay_ni(PortP, HUNDRED_MS * 10) == RIO_FAIL) {
 460                                 rio_dprintk(RIO_DEBUG_TTY, "RTA EINTR in delay \n");
 461                                 rv = -EINTR;
 462                                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 463                                 goto close_end;
 464                         }
 465                         rio_spin_lock_irqsave(&PortP->portSem, flags);
 466                 }
 467
 468         PortP->TxBufferIn = PortP->TxBufferOut = 0;
 469         repeat_this = 0xff;
 470
 471         PortP->InUse = 0;
 472         if ((PortP->State & (RIO_LOPEN | RIO_MOPEN))) {
 473                 /*
 474                  ** The port has been re-opened for the other task -
 475                  ** return, pretending that we are still active.
 476                  */
 477                 rio_dprintk(RIO_DEBUG_TTY, "Channel %d re-open!\n", PortP->PortNum);
 478                 PortP->State &= ~RIO_CLOSING;
 479                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 480                 if (PortP->firstOpen)
 481                         PortP->firstOpen--;
 482                 return -EIO;
 483         }
 484
 485         if (p->RIOHalted) {
 486                 RIOClearUp(PortP);
 487                 goto close_end;
 488         }
 489
 490         /* Can't call RIOShortCommand with the port locked. */
 491         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 492
 493         if (RIOShortCommand(p, PortP, RIOC_CLOSE, 1, 0) == RIO_FAIL) {
 494                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 495                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 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, RIOC_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                                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 512                                 goto close_end;
 513                         }
 514                         if (RIODelay(PortP, HUNDRED_MS) == RIO_FAIL) {
 515                                 rio_dprintk(RIO_DEBUG_TTY, "RTA EINTR in delay \n");
 516                                 RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE);
 517                                 break;
 518                         }
 519                 }
 520         rio_spin_lock_irqsave(&PortP->portSem, flags);
 521         rio_dprintk(RIO_DEBUG_TTY, "Close: try was %d on completion\n", try);
 522
 523         /* RIOPreemptiveCmd(p, PortP, RIOC_FCLOSE); */
 524
 525 /*
 526 ** 15.10.1998 ARG - ESIL 0761 part fix
 527 ** 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.
 528 */
 529         PortP->Config &= ~(RIO_CTSFLOW | RIO_RTSFLOW);
 530
 531         /*
 532          ** Count opens for port statistics reporting
 533          */
 534         if (PortP->statsGather)
 535                 PortP->closes++;
 536
 537 close_end:
 538         /* XXX: Why would a "DELETED" flag be reset here? I'd have
 539            thought that a "deleted" flag means that the port was
 540            permanently gone, but here we can make it reappear by it
 541            being in close during the "deletion".
 542          */
 543         PortP->State &= ~(RIO_CLOSING | RIO_DELETED);
 544         if (PortP->firstOpen)
 545                 PortP->firstOpen--;
 546         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 547         rio_dprintk(RIO_DEBUG_TTY, "Return from close\n");
 548         return rv;
 549 }
 550
 551
 552
 553 static void RIOClearUp(struct Port *PortP)
 554 {
 555         rio_dprintk(RIO_DEBUG_TTY, "RIOHalted set\n");
 556         PortP->Config = 0;      /* Direct semaphore */
 557         PortP->PortState = 0;
 558         PortP->firstOpen = 0;
 559         PortP->FlushCmdBodge = 0;
 560         PortP->ModemState = PortP->CookMode = 0;
 561         PortP->Mapped = 0;
 562         PortP->WflushFlag = 0;
 563         PortP->MagicFlags = 0;
 564         PortP->RxDataStart = 0;
 565         PortP->TxBufferIn = 0;
 566         PortP->TxBufferOut = 0;
 567 }
 568
 569 /*
 570 ** Put a command onto a port.
 571 ** The PortPointer, command, length and arg are passed.
 572 ** The len is the length *inclusive* of the command byte,
 573 ** and so for a command that takes no data, len==1.
 574 ** The arg is a single byte, and is only used if len==2.
 575 ** Other values of len aren't allowed, and will cause
 576 ** a panic.
 577 */
 578 int RIOShortCommand(struct rio_info *p, struct Port *PortP, int command, int len, int arg)
 579 {
 580         struct PKT __iomem *PacketP;
 581         int retries = 20;       /* at 10 per second -> 2 seconds */
 582         unsigned long flags;
 583
 584         rio_dprintk(RIO_DEBUG_TTY, "entering shortcommand.\n");
 585
 586         if (PortP->State & RIO_DELETED) {
 587                 rio_dprintk(RIO_DEBUG_TTY, "Short command to deleted RTA ignored\n");
 588                 return RIO_FAIL;
 589         }
 590         rio_spin_lock_irqsave(&PortP->portSem, flags);
 591
 592         /*
 593          ** If the port is in use for pre-emptive command, then wait for it to
 594          ** be free again.
 595          */
 596         while ((PortP->InUse != NOT_INUSE) && !p->RIOHalted) {
 597                 rio_dprintk(RIO_DEBUG_TTY, "Waiting for not in use (%d)\n", retries);
 598                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 599                 if (retries-- <= 0) {
 600                         return RIO_FAIL;
 601                 }
 602                 if (RIODelay_ni(PortP, HUNDRED_MS) == RIO_FAIL) {
 603                         return RIO_FAIL;
 604                 }
 605                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 606         }
 607         if (PortP->State & RIO_DELETED) {
 608                 rio_dprintk(RIO_DEBUG_TTY, "Short command to deleted RTA ignored\n");
 609                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 610                 return RIO_FAIL;
 611         }
 612
 613         while (!can_add_transmit(&PacketP, PortP) && !p->RIOHalted) {
 614                 rio_dprintk(RIO_DEBUG_TTY, "Waiting to add short command to queue (%d)\n", retries);
 615                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 616                 if (retries-- <= 0) {
 617                         rio_dprintk(RIO_DEBUG_TTY, "out of tries. Failing\n");
 618                         return RIO_FAIL;
 619                 }
 620                 if (RIODelay_ni(PortP, HUNDRED_MS) == RIO_FAIL) {
 621                         return RIO_FAIL;
 622                 }
 623                 rio_spin_lock_irqsave(&PortP->portSem, flags);
 624         }
 625
 626         if (p->RIOHalted) {
 627                 rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 628                 return RIO_FAIL;
 629         }
 630
 631         /*
 632          ** set the command byte and the argument byte
 633          */
 634         writeb(command, &PacketP->data[0]);
 635
 636         if (len == 2)
 637                 writeb(arg, &PacketP->data[1]);
 638
 639         /*
 640          ** set the length of the packet and set the command bit.
 641          */
 642         writeb(PKT_CMD_BIT | len, &PacketP->len);
 643
 644         add_transmit(PortP);
 645         /*
 646          ** Count characters transmitted for port statistics reporting
 647          */
 648         if (PortP->statsGather)
 649                 PortP->txchars += len;
 650
 651         rio_spin_unlock_irqrestore(&PortP->portSem, flags);
 652         return p->RIOHalted ? RIO_FAIL : ~RIO_FAIL;
 653 }
 654
 655