sound/hda/hdac_controller.c

   1 /*
   2  * HD-audio controller helpers
   3  */
   4
   5 #include <linux/kernel.h>
   6 #include <linux/delay.h>
   7 #include <linux/export.h>
   8 #include <sound/core.h>
   9 #include <sound/hdaudio.h>
  10 #include <sound/hda_register.h>
  11
  12 /* clear CORB read pointer properly */
  13 static void azx_clear_corbrp(struct hdac_bus *bus)
  14 {
  15         int timeout;
  16
  17         for (timeout = 1000; timeout > 0; timeout--) {
  18                 if (snd_hdac_chip_readw(bus, CORBRP) & AZX_CORBRP_RST)
  19                         break;
  20                 udelay(1);
  21         }
  22         if (timeout <= 0)
  23                 dev_err(bus->dev, "CORB reset timeout#1, CORBRP = %d\n",
  24                         snd_hdac_chip_readw(bus, CORBRP));
  25
  26         snd_hdac_chip_writew(bus, CORBRP, 0);
  27         for (timeout = 1000; timeout > 0; timeout--) {
  28                 if (snd_hdac_chip_readw(bus, CORBRP) == 0)
  29                         break;
  30                 udelay(1);
  31         }
  32         if (timeout <= 0)
  33                 dev_err(bus->dev, "CORB reset timeout#2, CORBRP = %d\n",
  34                         snd_hdac_chip_readw(bus, CORBRP));
  35 }
  36
  37 /**
  38  * snd_hdac_bus_init_cmd_io - set up CORB/RIRB buffers
  39  * @bus: HD-audio core bus
  40  */
  41 void snd_hdac_bus_init_cmd_io(struct hdac_bus *bus)
  42 {
  43         spin_lock_irq(&bus->reg_lock);
  44         /* CORB set up */
  45         bus->corb.addr = bus->rb.addr;
  46         bus->corb.buf = (__le32 *)bus->rb.area;
  47         snd_hdac_chip_writel(bus, CORBLBASE, (u32)bus->corb.addr);
  48         snd_hdac_chip_writel(bus, CORBUBASE, upper_32_bits(bus->corb.addr));
  49
  50         /* set the corb size to 256 entries (ULI requires explicitly) */
  51         snd_hdac_chip_writeb(bus, CORBSIZE, 0x02);
  52         /* set the corb write pointer to 0 */
  53         snd_hdac_chip_writew(bus, CORBWP, 0);
  54
  55         /* reset the corb hw read pointer */
  56         snd_hdac_chip_writew(bus, CORBRP, AZX_CORBRP_RST);
  57         if (!bus->corbrp_self_clear)
  58                 azx_clear_corbrp(bus);
  59
  60         /* enable corb dma */
  61         snd_hdac_chip_writeb(bus, CORBCTL, AZX_CORBCTL_RUN);
  62
  63         /* RIRB set up */
  64         bus->rirb.addr = bus->rb.addr + 2048;
  65         bus->rirb.buf = (__le32 *)(bus->rb.area + 2048);
  66         bus->rirb.wp = bus->rirb.rp = 0;
  67         memset(bus->rirb.cmds, 0, sizeof(bus->rirb.cmds));
  68         snd_hdac_chip_writel(bus, RIRBLBASE, (u32)bus->rirb.addr);
  69         snd_hdac_chip_writel(bus, RIRBUBASE, upper_32_bits(bus->rirb.addr));
  70
  71         /* set the rirb size to 256 entries (ULI requires explicitly) */
  72         snd_hdac_chip_writeb(bus, RIRBSIZE, 0x02);
  73         /* reset the rirb hw write pointer */
  74         snd_hdac_chip_writew(bus, RIRBWP, AZX_RIRBWP_RST);
  75         /* set N=1, get RIRB response interrupt for new entry */
  76         snd_hdac_chip_writew(bus, RINTCNT, 1);
  77         /* enable rirb dma and response irq */
  78         snd_hdac_chip_writeb(bus, RIRBCTL, AZX_RBCTL_DMA_EN | AZX_RBCTL_IRQ_EN);
  79         spin_unlock_irq(&bus->reg_lock);
  80 }
  81 EXPORT_SYMBOL_GPL(snd_hdac_bus_init_cmd_io);
  82
  83 /* wait for cmd dmas till they are stopped */
  84 static void hdac_wait_for_cmd_dmas(struct hdac_bus *bus)
  85 {
  86         unsigned long timeout;
  87
  88         timeout = jiffies + msecs_to_jiffies(100);
  89         while ((snd_hdac_chip_readb(bus, RIRBCTL) & AZX_RBCTL_DMA_EN)
  90                 && time_before(jiffies, timeout))
  91                 udelay(10);
  92
  93         timeout = jiffies + msecs_to_jiffies(100);
  94         while ((snd_hdac_chip_readb(bus, CORBCTL) & AZX_CORBCTL_RUN)
  95                 && time_before(jiffies, timeout))
  96                 udelay(10);
  97 }
  98
  99 /**
 100  * snd_hdac_bus_stop_cmd_io - clean up CORB/RIRB buffers
 101  * @bus: HD-audio core bus
 102  */
 103 void snd_hdac_bus_stop_cmd_io(struct hdac_bus *bus)
 104 {
 105         spin_lock_irq(&bus->reg_lock);
 106         /* disable ringbuffer DMAs */
 107         snd_hdac_chip_writeb(bus, RIRBCTL, 0);
 108         snd_hdac_chip_writeb(bus, CORBCTL, 0);
 109         spin_unlock_irq(&bus->reg_lock);
 110
 111         hdac_wait_for_cmd_dmas(bus);
 112
 113         spin_lock_irq(&bus->reg_lock);
 114         /* disable unsolicited responses */
 115         snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_UNSOL, 0);
 116         spin_unlock_irq(&bus->reg_lock);
 117 }
 118 EXPORT_SYMBOL_GPL(snd_hdac_bus_stop_cmd_io);
 119
 120 static unsigned int azx_command_addr(u32 cmd)
 121 {
 122         unsigned int addr = cmd >> 28;
 123
 124         if (snd_BUG_ON(addr >= HDA_MAX_CODECS))
 125                 addr = 0;
 126         return addr;
 127 }
 128
 129 /**
 130  * snd_hdac_bus_send_cmd - send a command verb via CORB
 131  * @bus: HD-audio core bus
 132  * @val: encoded verb value to send
 133  *
 134  * Returns zero for success or a negative error code.
 135  */
 136 int snd_hdac_bus_send_cmd(struct hdac_bus *bus, unsigned int val)
 137 {
 138         unsigned int addr = azx_command_addr(val);
 139         unsigned int wp, rp;
 140
 141         spin_lock_irq(&bus->reg_lock);
 142
 143         bus->last_cmd[azx_command_addr(val)] = val;
 144
 145         /* add command to corb */
 146         wp = snd_hdac_chip_readw(bus, CORBWP);
 147         if (wp == 0xffff) {
 148                 /* something wrong, controller likely turned to D3 */
 149                 spin_unlock_irq(&bus->reg_lock);
 150                 return -EIO;
 151         }
 152         wp++;
 153         wp %= AZX_MAX_CORB_ENTRIES;
 154
 155         rp = snd_hdac_chip_readw(bus, CORBRP);
 156         if (wp == rp) {
 157                 /* oops, it's full */
 158                 spin_unlock_irq(&bus->reg_lock);
 159                 return -EAGAIN;
 160         }
 161
 162         bus->rirb.cmds[addr]++;
 163         bus->corb.buf[wp] = cpu_to_le32(val);
 164         snd_hdac_chip_writew(bus, CORBWP, wp);
 165
 166         spin_unlock_irq(&bus->reg_lock);
 167
 168         return 0;
 169 }
 170 EXPORT_SYMBOL_GPL(snd_hdac_bus_send_cmd);
 171
 172 #define AZX_RIRB_EX_UNSOL_EV    (1<<4)
 173
 174 /**
 175  * snd_hdac_bus_update_rirb - retrieve RIRB entries
 176  * @bus: HD-audio core bus
 177  *
 178  * Usually called from interrupt handler.
 179  */
 180 void snd_hdac_bus_update_rirb(struct hdac_bus *bus)
 181 {
 182         unsigned int rp, wp;
 183         unsigned int addr;
 184         u32 res, res_ex;
 185
 186         wp = snd_hdac_chip_readw(bus, RIRBWP);
 187         if (wp == 0xffff) {
 188                 /* something wrong, controller likely turned to D3 */
 189                 return;
 190         }
 191
 192         if (wp == bus->rirb.wp)
 193                 return;
 194         bus->rirb.wp = wp;
 195
 196         while (bus->rirb.rp != wp) {
 197                 bus->rirb.rp++;
 198                 bus->rirb.rp %= AZX_MAX_RIRB_ENTRIES;
 199
 200                 rp = bus->rirb.rp << 1; /* an RIRB entry is 8-bytes */
 201                 res_ex = le32_to_cpu(bus->rirb.buf[rp + 1]);
 202                 res = le32_to_cpu(bus->rirb.buf[rp]);
 203                 addr = res_ex & 0xf;
 204                 if (addr >= HDA_MAX_CODECS) {
 205                         dev_err(bus->dev,
 206                                 "spurious response %#x:%#x, rp = %d, wp = %d",
 207                                 res, res_ex, bus->rirb.rp, wp);
 208                         snd_BUG();
 209                 } else if (res_ex & AZX_RIRB_EX_UNSOL_EV)
 210                         snd_hdac_bus_queue_event(bus, res, res_ex);
 211                 else if (bus->rirb.cmds[addr]) {
 212                         bus->rirb.res[addr] = res;
 213                         bus->rirb.cmds[addr]--;
 214                 } else {
 215                         dev_err_ratelimited(bus->dev,
 216                                 "spurious response %#x:%#x, last cmd=%#08x\n",
 217                                 res, res_ex, bus->last_cmd[addr]);
 218                 }
 219         }
 220 }
 221 EXPORT_SYMBOL_GPL(snd_hdac_bus_update_rirb);
 222
 223 /**
 224  * snd_hdac_bus_get_response - receive a response via RIRB
 225  * @bus: HD-audio core bus
 226  * @addr: codec address
 227  * @res: pointer to store the value, NULL when not needed
 228  *
 229  * Returns zero if a value is read, or a negative error code.
 230  */
 231 int snd_hdac_bus_get_response(struct hdac_bus *bus, unsigned int addr,
 232                               unsigned int *res)
 233 {
 234         unsigned long timeout;
 235         unsigned long loopcounter;
 236
 237         timeout = jiffies + msecs_to_jiffies(1000);
 238
 239         for (loopcounter = 0;; loopcounter++) {
 240                 spin_lock_irq(&bus->reg_lock);
 241                 if (!bus->rirb.cmds[addr]) {
 242                         if (res)
 243                                 *res = bus->rirb.res[addr]; /* the last value */
 244                         spin_unlock_irq(&bus->reg_lock);
 245                         return 0;
 246                 }
 247                 spin_unlock_irq(&bus->reg_lock);
 248                 if (time_after(jiffies, timeout))
 249                         break;
 250                 if (loopcounter > 3000)
 251                         msleep(2); /* temporary workaround */
 252                 else {
 253                         udelay(10);
 254                         cond_resched();
 255                 }
 256         }
 257
 258         return -EIO;
 259 }
 260 EXPORT_SYMBOL_GPL(snd_hdac_bus_get_response);
 261
 262 #define HDAC_MAX_CAPS 10
 263 /**
 264  * snd_hdac_bus_parse_capabilities - parse capability structure
 265  * @bus: the pointer to bus object
 266  *
 267  * Returns 0 if successful, or a negative error code.
 268  */
 269 int snd_hdac_bus_parse_capabilities(struct hdac_bus *bus)
 270 {
 271         unsigned int cur_cap;
 272         unsigned int offset;
 273         unsigned int counter = 0;
 274
 275         offset = snd_hdac_chip_readw(bus, LLCH);
 276
 277         /* Lets walk the linked capabilities list */
 278         do {
 279                 cur_cap = _snd_hdac_chip_readl(bus, offset);
 280
 281                 dev_dbg(bus->dev, "Capability version: 0x%x\n",
 282                         (cur_cap & AZX_CAP_HDR_VER_MASK) >> AZX_CAP_HDR_VER_OFF);
 283
 284                 dev_dbg(bus->dev, "HDA capability ID: 0x%x\n",
 285                         (cur_cap & AZX_CAP_HDR_ID_MASK) >> AZX_CAP_HDR_ID_OFF);
 286
 287                 if (cur_cap == -1) {
 288                         dev_dbg(bus->dev, "Invalid capability reg read\n");
 289                         break;
 290                 }
 291
 292                 switch ((cur_cap & AZX_CAP_HDR_ID_MASK) >> AZX_CAP_HDR_ID_OFF) {
 293                 case AZX_ML_CAP_ID:
 294                         dev_dbg(bus->dev, "Found ML capability\n");
 295                         bus->mlcap = bus->remap_addr + offset;
 296                         break;
 297
 298                 case AZX_GTS_CAP_ID:
 299                         dev_dbg(bus->dev, "Found GTS capability offset=%x\n", offset);
 300                         bus->gtscap = bus->remap_addr + offset;
 301                         break;
 302
 303                 case AZX_PP_CAP_ID:
 304                         /* PP capability found, the Audio DSP is present */
 305                         dev_dbg(bus->dev, "Found PP capability offset=%x\n", offset);
 306                         bus->ppcap = bus->remap_addr + offset;
 307                         break;
 308
 309                 case AZX_SPB_CAP_ID:
 310                         /* SPIB capability found, handler function */
 311                         dev_dbg(bus->dev, "Found SPB capability\n");
 312                         bus->spbcap = bus->remap_addr + offset;
 313                         break;
 314
 315                 case AZX_DRSM_CAP_ID:
 316                         /* DMA resume  capability found, handler function */
 317                         dev_dbg(bus->dev, "Found DRSM capability\n");
 318                         bus->drsmcap = bus->remap_addr + offset;
 319                         break;
 320
 321                 default:
 322                         dev_err(bus->dev, "Unknown capability %d\n", cur_cap);
 323                         cur_cap = 0;
 324                         break;
 325                 }
 326
 327                 counter++;
 328
 329                 if (counter > HDAC_MAX_CAPS) {
 330                         dev_err(bus->dev, "We exceeded HDAC capabilities!!!\n");
 331                         break;
 332                 }
 333
 334                 /* read the offset of next capability */
 335                 offset = cur_cap & AZX_CAP_HDR_NXT_PTR_MASK;
 336
 337         } while (offset);
 338
 339         return 0;
 340 }
 341 EXPORT_SYMBOL_GPL(snd_hdac_bus_parse_capabilities);
 342
 343 /*
 344  * Lowlevel interface
 345  */
 346
 347 /**
 348  * snd_hdac_bus_enter_link_reset - enter link reset
 349  * @bus: HD-audio core bus
 350  *
 351  * Enter to the link reset state.
 352  */
 353 void snd_hdac_bus_enter_link_reset(struct hdac_bus *bus)
 354 {
 355         unsigned long timeout;
 356
 357         /* reset controller */
 358         snd_hdac_chip_updatel(bus, GCTL, AZX_GCTL_RESET, 0);
 359
 360         timeout = jiffies + msecs_to_jiffies(100);
 361         while ((snd_hdac_chip_readb(bus, GCTL) & AZX_GCTL_RESET) &&
 362                time_before(jiffies, timeout))
 363                 usleep_range(500, 1000);
 364 }
 365 EXPORT_SYMBOL_GPL(snd_hdac_bus_enter_link_reset);
 366
 367 /**
 368  * snd_hdac_bus_exit_link_reset - exit link reset
 369  * @bus: HD-audio core bus
 370  *
 371  * Exit from the link reset state.
 372  */
 373 void snd_hdac_bus_exit_link_reset(struct hdac_bus *bus)
 374 {
 375         unsigned long timeout;
 376
 377         snd_hdac_chip_updateb(bus, GCTL, 0, AZX_GCTL_RESET);
 378
 379         timeout = jiffies + msecs_to_jiffies(100);
 380         while (!snd_hdac_chip_readb(bus, GCTL) && time_before(jiffies, timeout))
 381                 usleep_range(500, 1000);
 382 }
 383 EXPORT_SYMBOL_GPL(snd_hdac_bus_exit_link_reset);
 384
 385 /* reset codec link */
 386 static int azx_reset(struct hdac_bus *bus, bool full_reset)
 387 {
 388         if (!full_reset)
 389                 goto skip_reset;
 390
 391         /* clear STATESTS */
 392         snd_hdac_chip_writew(bus, STATESTS, STATESTS_INT_MASK);
 393
 394         /* reset controller */
 395         snd_hdac_bus_enter_link_reset(bus);
 396
 397         /* delay for >= 100us for codec PLL to settle per spec
 398          * Rev 0.9 section 5.5.1
 399          */
 400         usleep_range(500, 1000);
 401
 402         /* Bring controller out of reset */
 403         snd_hdac_bus_exit_link_reset(bus);
 404
 405         /* Brent Chartrand said to wait >= 540us for codecs to initialize */
 406         usleep_range(1000, 1200);
 407
 408  skip_reset:
 409         /* check to see if controller is ready */
 410         if (!snd_hdac_chip_readb(bus, GCTL)) {
 411                 dev_dbg(bus->dev, "azx_reset: controller not ready!\n");
 412                 return -EBUSY;
 413         }
 414
 415         /* Accept unsolicited responses */
 416         snd_hdac_chip_updatel(bus, GCTL, 0, AZX_GCTL_UNSOL);
 417
 418         /* detect codecs */
 419         if (!bus->codec_mask) {
 420                 bus->codec_mask = snd_hdac_chip_readw(bus, STATESTS);
 421                 dev_dbg(bus->dev, "codec_mask = 0x%lx\n", bus->codec_mask);
 422         }
 423
 424         return 0;
 425 }
 426
 427 /* enable interrupts */
 428 static void azx_int_enable(struct hdac_bus *bus)
 429 {
 430         /* enable controller CIE and GIE */
 431         snd_hdac_chip_updatel(bus, INTCTL, 0, AZX_INT_CTRL_EN | AZX_INT_GLOBAL_EN);
 432 }
 433
 434 /* disable interrupts */
 435 static void azx_int_disable(struct hdac_bus *bus)
 436 {
 437         struct hdac_stream *azx_dev;
 438
 439         /* disable interrupts in stream descriptor */
 440         list_for_each_entry(azx_dev, &bus->stream_list, list)
 441                 snd_hdac_stream_updateb(azx_dev, SD_CTL, SD_INT_MASK, 0);
 442
 443         /* disable SIE for all streams */
 444         snd_hdac_chip_writeb(bus, INTCTL, 0);
 445
 446         /* disable controller CIE and GIE */
 447         snd_hdac_chip_updatel(bus, INTCTL, AZX_INT_CTRL_EN | AZX_INT_GLOBAL_EN, 0);
 448 }
 449
 450 /* clear interrupts */
 451 static void azx_int_clear(struct hdac_bus *bus)
 452 {
 453         struct hdac_stream *azx_dev;
 454
 455         /* clear stream status */
 456         list_for_each_entry(azx_dev, &bus->stream_list, list)
 457                 snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK);
 458
 459         /* clear STATESTS */
 460         snd_hdac_chip_writew(bus, STATESTS, STATESTS_INT_MASK);
 461
 462         /* clear rirb status */
 463         snd_hdac_chip_writeb(bus, RIRBSTS, RIRB_INT_MASK);
 464
 465         /* clear int status */
 466         snd_hdac_chip_writel(bus, INTSTS, AZX_INT_CTRL_EN | AZX_INT_ALL_STREAM);
 467 }
 468
 469 /**
 470  * snd_hdac_bus_init_chip - reset and start the controller registers
 471  * @bus: HD-audio core bus
 472  * @full_reset: Do full reset
 473  */
 474 bool snd_hdac_bus_init_chip(struct hdac_bus *bus, bool full_reset)
 475 {
 476         if (bus->chip_init)
 477                 return false;
 478
 479         /* reset controller */
 480         azx_reset(bus, full_reset);
 481
 482         /* initialize interrupts */
 483         azx_int_clear(bus);
 484         azx_int_enable(bus);
 485
 486         /* initialize the codec command I/O */
 487         snd_hdac_bus_init_cmd_io(bus);
 488
 489         /* program the position buffer */
 490         if (bus->use_posbuf && bus->posbuf.addr) {
 491                 snd_hdac_chip_writel(bus, DPLBASE, (u32)bus->posbuf.addr);
 492                 snd_hdac_chip_writel(bus, DPUBASE, upper_32_bits(bus->posbuf.addr));
 493         }
 494
 495         bus->chip_init = true;
 496         return true;
 497 }
 498 EXPORT_SYMBOL_GPL(snd_hdac_bus_init_chip);
 499
 500 /**
 501  * snd_hdac_bus_stop_chip - disable the whole IRQ and I/Os
 502  * @bus: HD-audio core bus
 503  */
 504 void snd_hdac_bus_stop_chip(struct hdac_bus *bus)
 505 {
 506         if (!bus->chip_init)
 507                 return;
 508
 509         /* disable interrupts */
 510         azx_int_disable(bus);
 511         azx_int_clear(bus);
 512
 513         /* disable CORB/RIRB */
 514         snd_hdac_bus_stop_cmd_io(bus);
 515
 516         /* disable position buffer */
 517         if (bus->posbuf.addr) {
 518                 snd_hdac_chip_writel(bus, DPLBASE, 0);
 519                 snd_hdac_chip_writel(bus, DPUBASE, 0);
 520         }
 521
 522         bus->chip_init = false;
 523 }
 524 EXPORT_SYMBOL_GPL(snd_hdac_bus_stop_chip);
 525
 526 /**
 527  * snd_hdac_bus_handle_stream_irq - interrupt handler for streams
 528  * @bus: HD-audio core bus
 529  * @status: INTSTS register value
 530  * @ask: callback to be called for woken streams
 531  *
 532  * Returns the bits of handled streams, or zero if no stream is handled.
 533  */
 534 int snd_hdac_bus_handle_stream_irq(struct hdac_bus *bus, unsigned int status,
 535                                     void (*ack)(struct hdac_bus *,
 536                                                 struct hdac_stream *))
 537 {
 538         struct hdac_stream *azx_dev;
 539         u8 sd_status;
 540         int handled = 0;
 541
 542         list_for_each_entry(azx_dev, &bus->stream_list, list) {
 543                 if (status & azx_dev->sd_int_sta_mask) {
 544                         sd_status = snd_hdac_stream_readb(azx_dev, SD_STS);
 545                         snd_hdac_stream_writeb(azx_dev, SD_STS, SD_INT_MASK);
 546                         handled |= 1 << azx_dev->index;
 547                         if (!azx_dev->substream || !azx_dev->running ||
 548                             !(sd_status & SD_INT_COMPLETE))
 549                                 continue;
 550                         if (ack)
 551                                 ack(bus, azx_dev);
 552                 }
 553         }
 554         return handled;
 555 }
 556 EXPORT_SYMBOL_GPL(snd_hdac_bus_handle_stream_irq);
 557
 558 /**
 559  * snd_hdac_bus_alloc_stream_pages - allocate BDL and other buffers
 560  * @bus: HD-audio core bus
 561  *
 562  * Call this after assigning the all streams.
 563  * Returns zero for success, or a negative error code.
 564  */
 565 int snd_hdac_bus_alloc_stream_pages(struct hdac_bus *bus)
 566 {
 567         struct hdac_stream *s;
 568         int num_streams = 0;
 569         int err;
 570
 571         list_for_each_entry(s, &bus->stream_list, list) {
 572                 /* allocate memory for the BDL for each stream */
 573                 err = bus->io_ops->dma_alloc_pages(bus, SNDRV_DMA_TYPE_DEV,
 574                                                    BDL_SIZE, &s->bdl);
 575                 num_streams++;
 576                 if (err < 0)
 577                         return -ENOMEM;
 578         }
 579
 580         if (WARN_ON(!num_streams))
 581                 return -EINVAL;
 582         /* allocate memory for the position buffer */
 583         err = bus->io_ops->dma_alloc_pages(bus, SNDRV_DMA_TYPE_DEV,
 584                                            num_streams * 8, &bus->posbuf);
 585         if (err < 0)
 586                 return -ENOMEM;
 587         list_for_each_entry(s, &bus->stream_list, list)
 588                 s->posbuf = (__le32 *)(bus->posbuf.area + s->index * 8);
 589
 590         /* single page (at least 4096 bytes) must suffice for both ringbuffes */
 591         return bus->io_ops->dma_alloc_pages(bus, SNDRV_DMA_TYPE_DEV,
 592                                             PAGE_SIZE, &bus->rb);
 593 }
 594 EXPORT_SYMBOL_GPL(snd_hdac_bus_alloc_stream_pages);
 595
 596 /**
 597  * snd_hdac_bus_free_stream_pages - release BDL and other buffers
 598  * @bus: HD-audio core bus
 599  */
 600 void snd_hdac_bus_free_stream_pages(struct hdac_bus *bus)
 601 {
 602         struct hdac_stream *s;
 603
 604         list_for_each_entry(s, &bus->stream_list, list) {
 605                 if (s->bdl.area)
 606                         bus->io_ops->dma_free_pages(bus, &s->bdl);
 607         }
 608
 609         if (bus->rb.area)
 610                 bus->io_ops->dma_free_pages(bus, &bus->rb);
 611         if (bus->posbuf.area)
 612                 bus->io_ops->dma_free_pages(bus, &bus->posbuf);
 613 }
 614 EXPORT_SYMBOL_GPL(snd_hdac_bus_free_stream_pages);