1 /*- 2 * Copyright 2003 Eric Anholt 3 * All Rights Reserved. 4 * 5 * Permission is hereby granted, free of charge, to any person obtaining a 6 * copy of this software and associated documentation files (the "Software"), 7 * to deal in the Software without restriction, including without limitation 8 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 9 * and/or sell copies of the Software, and to permit persons to whom the 10 * Software is furnished to do so, subject to the following conditions: 11 * 12 * The above copyright notice and this permission notice (including the next 13 * paragraph) shall be included in all copies or substantial portions of the 14 * Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * ERIC ANHOLT BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER 20 * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 22 * 23 * Authors: 24 * Eric Anholt <anholt@FreeBSD.org> 25 * 26 * $FreeBSD: src/sys/dev/drm2/drm_irq.c,v 1.1 2012/05/22 11:07:44 kib Exp $ 27 */ 28 29 /** @file drm_irq.c 30 * Support code for handling setup/teardown of interrupt handlers and 31 * handing interrupt handlers off to the drivers. 32 */ 33 34 #include <linux/export.h> 35 #include <linux/mutex.h> 36 #include <linux/timer.h> 37 #include <drm/drmP.h> 38 39 MALLOC_DEFINE(DRM_MEM_VBLANK, "drm_vblank", "DRM VBLANK Handling Data"); 40 41 /* Access macro for slots in vblank timestamp ringbuffer. */ 42 #define vblanktimestamp(dev, crtc, count) ( \ 43 (dev)->_vblank_time[(crtc) * DRM_VBLANKTIME_RBSIZE + \ 44 ((count) % DRM_VBLANKTIME_RBSIZE)]) 45 46 /* Retry timestamp calculation up to 3 times to satisfy 47 * drm_timestamp_precision before giving up. 48 */ 49 #define DRM_TIMESTAMP_MAXRETRIES 3 50 51 /* Threshold in nanoseconds for detection of redundant 52 * vblank irq in drm_handle_vblank(). 1 msec should be ok. 53 */ 54 #define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000 55 56 int drm_irq_by_busid(struct drm_device *dev, void *data, 57 struct drm_file *file_priv) 58 { 59 struct drm_irq_busid *irq = data; 60 61 if ((irq->busnum >> 8) != dev->pci_domain || 62 (irq->busnum & 0xff) != dev->pci_bus || 63 irq->devnum != dev->pci_slot || 64 irq->funcnum != dev->pci_func) 65 return EINVAL; 66 67 irq->irq = dev->irq; 68 69 DRM_DEBUG("%d:%d:%d => IRQ %d\n", 70 irq->busnum, irq->devnum, irq->funcnum, irq->irq); 71 72 return 0; 73 } 74 75 int 76 drm_irq_install(struct drm_device *dev) 77 { 78 int retcode; 79 80 if (dev->irq == 0 || dev->dev_private == NULL) 81 return (EINVAL); 82 83 DRM_DEBUG("irq=%d\n", dev->irq); 84 85 DRM_LOCK(dev); 86 if (dev->irq_enabled) { 87 DRM_UNLOCK(dev); 88 return EBUSY; 89 } 90 dev->irq_enabled = 1; 91 92 dev->context_flag = 0; 93 94 /* Before installing handler */ 95 if (dev->driver->irq_preinstall) 96 dev->driver->irq_preinstall(dev); 97 DRM_UNLOCK(dev); 98 99 /* Install handler */ 100 retcode = bus_setup_intr(dev->dev, dev->irqr, INTR_MPSAFE, 101 dev->driver->irq_handler, dev, &dev->irqh, &dev->irq_lock); 102 if (retcode != 0) 103 goto err; 104 105 /* After installing handler */ 106 DRM_LOCK(dev); 107 if (dev->driver->irq_postinstall) 108 dev->driver->irq_postinstall(dev); 109 DRM_UNLOCK(dev); 110 111 return (0); 112 err: 113 device_printf(dev->dev, "Error setting interrupt: %d\n", retcode); 114 dev->irq_enabled = 0; 115 116 return (retcode); 117 } 118 119 int drm_irq_uninstall(struct drm_device *dev) 120 { 121 int i; 122 123 if (!dev->irq_enabled) 124 return EINVAL; 125 126 dev->irq_enabled = 0; 127 128 /* 129 * Wake up any waiters so they don't hang. 130 */ 131 if (dev->num_crtcs) { 132 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE); 133 for (i = 0; i < dev->num_crtcs; i++) { 134 wakeup(&dev->_vblank_count[i]); 135 dev->vblank_enabled[i] = 0; 136 dev->last_vblank[i] = 137 dev->driver->get_vblank_counter(dev, i); 138 } 139 lockmgr(&dev->vbl_lock, LK_RELEASE); 140 } 141 142 DRM_DEBUG("irq=%d\n", dev->irq); 143 144 if (dev->driver->irq_uninstall) 145 dev->driver->irq_uninstall(dev); 146 147 DRM_UNLOCK(dev); 148 bus_teardown_intr(dev->dev, dev->irqr, dev->irqh); 149 DRM_LOCK(dev); 150 151 return 0; 152 } 153 154 int drm_control(struct drm_device *dev, void *data, struct drm_file *file_priv) 155 { 156 struct drm_control *ctl = data; 157 int err; 158 159 switch (ctl->func) { 160 case DRM_INST_HANDLER: 161 /* Handle drivers whose DRM used to require IRQ setup but the 162 * no longer does. 163 */ 164 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) 165 return 0; 166 if (drm_core_check_feature(dev, DRIVER_MODESET)) 167 return 0; 168 if (dev->if_version < DRM_IF_VERSION(1, 2) && 169 ctl->irq != dev->irq) 170 return EINVAL; 171 return drm_irq_install(dev); 172 case DRM_UNINST_HANDLER: 173 if (!drm_core_check_feature(dev, DRIVER_HAVE_IRQ)) 174 return 0; 175 if (drm_core_check_feature(dev, DRIVER_MODESET)) 176 return 0; 177 DRM_LOCK(dev); 178 err = drm_irq_uninstall(dev); 179 DRM_UNLOCK(dev); 180 return err; 181 default: 182 return EINVAL; 183 } 184 } 185 186 #define NSEC_PER_USEC 1000L 187 #define NSEC_PER_SEC 1000000000L 188 189 int64_t 190 timeval_to_ns(const struct timeval *tv) 191 { 192 return ((int64_t)tv->tv_sec * NSEC_PER_SEC) + 193 tv->tv_usec * NSEC_PER_USEC; 194 } 195 196 struct timeval 197 ns_to_timeval(const int64_t nsec) 198 { 199 struct timeval tv; 200 long rem; 201 202 if (nsec == 0) { 203 tv.tv_sec = 0; 204 tv.tv_usec = 0; 205 return (tv); 206 } 207 208 tv.tv_sec = nsec / NSEC_PER_SEC; 209 rem = nsec % NSEC_PER_SEC; 210 if (rem < 0) { 211 tv.tv_sec--; 212 rem += NSEC_PER_SEC; 213 } 214 tv.tv_usec = rem / 1000; 215 return (tv); 216 } 217 218 /* 219 * Clear vblank timestamp buffer for a crtc. 220 */ 221 static void clear_vblank_timestamps(struct drm_device *dev, int crtc) 222 { 223 memset(&dev->_vblank_time[crtc * DRM_VBLANKTIME_RBSIZE], 0, 224 DRM_VBLANKTIME_RBSIZE * sizeof(struct timeval)); 225 } 226 227 static int64_t 228 abs64(int64_t x) 229 { 230 231 return (x < 0 ? -x : x); 232 } 233 234 /* 235 * Disable vblank irq's on crtc, make sure that last vblank count 236 * of hardware and corresponding consistent software vblank counter 237 * are preserved, even if there are any spurious vblank irq's after 238 * disable. 239 */ 240 static void vblank_disable_and_save(struct drm_device *dev, int crtc) 241 { 242 u32 vblcount; 243 int64_t diff_ns; 244 int vblrc; 245 struct timeval tvblank; 246 247 /* Prevent vblank irq processing while disabling vblank irqs, 248 * so no updates of timestamps or count can happen after we've 249 * disabled. Needed to prevent races in case of delayed irq's. 250 */ 251 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE); 252 253 dev->driver->disable_vblank(dev, crtc); 254 dev->vblank_enabled[crtc] = 0; 255 256 /* No further vblank irq's will be processed after 257 * this point. Get current hardware vblank count and 258 * vblank timestamp, repeat until they are consistent. 259 * 260 * FIXME: There is still a race condition here and in 261 * drm_update_vblank_count() which can cause off-by-one 262 * reinitialization of software vblank counter. If gpu 263 * vblank counter doesn't increment exactly at the leading 264 * edge of a vblank interval, then we can lose 1 count if 265 * we happen to execute between start of vblank and the 266 * delayed gpu counter increment. 267 */ 268 do { 269 dev->last_vblank[crtc] = dev->driver->get_vblank_counter(dev, crtc); 270 vblrc = drm_get_last_vbltimestamp(dev, crtc, &tvblank, 0); 271 } while (dev->last_vblank[crtc] != dev->driver->get_vblank_counter(dev, crtc)); 272 273 /* Compute time difference to stored timestamp of last vblank 274 * as updated by last invocation of drm_handle_vblank() in vblank irq. 275 */ 276 vblcount = atomic_read(&dev->_vblank_count[crtc]); 277 diff_ns = timeval_to_ns(&tvblank) - 278 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount)); 279 280 /* If there is at least 1 msec difference between the last stored 281 * timestamp and tvblank, then we are currently executing our 282 * disable inside a new vblank interval, the tvblank timestamp 283 * corresponds to this new vblank interval and the irq handler 284 * for this vblank didn't run yet and won't run due to our disable. 285 * Therefore we need to do the job of drm_handle_vblank() and 286 * increment the vblank counter by one to account for this vblank. 287 * 288 * Skip this step if there isn't any high precision timestamp 289 * available. In that case we can't account for this and just 290 * hope for the best. 291 */ 292 if ((vblrc > 0) && (abs64(diff_ns) > 1000000)) { 293 atomic_inc(&dev->_vblank_count[crtc]); 294 } 295 296 /* Invalidate all timestamps while vblank irq's are off. */ 297 clear_vblank_timestamps(dev, crtc); 298 299 lockmgr(&dev->vblank_time_lock, LK_RELEASE); 300 } 301 302 static void vblank_disable_fn(unsigned long arg) 303 { 304 struct drm_device *dev = (struct drm_device *)arg; 305 int i; 306 307 if (!dev->vblank_disable_allowed) 308 return; 309 310 for (i = 0; i < dev->num_crtcs; i++) { 311 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE); 312 if (atomic_read(&dev->vblank_refcount[i]) == 0 && 313 dev->vblank_enabled[i]) { 314 DRM_DEBUG("disabling vblank on crtc %d\n", i); 315 vblank_disable_and_save(dev, i); 316 } 317 lockmgr(&dev->vbl_lock, LK_RELEASE); 318 } 319 } 320 321 void drm_vblank_cleanup(struct drm_device *dev) 322 { 323 /* Bail if the driver didn't call drm_vblank_init() */ 324 if (dev->num_crtcs == 0) 325 return; 326 327 del_timer_sync(&dev->vblank_disable_timer); 328 329 vblank_disable_fn((unsigned long)dev); 330 331 drm_free(dev->_vblank_count, DRM_MEM_VBLANK); 332 drm_free(dev->vblank_refcount, DRM_MEM_VBLANK); 333 drm_free(dev->vblank_enabled, DRM_MEM_VBLANK); 334 drm_free(dev->last_vblank, DRM_MEM_VBLANK); 335 drm_free(dev->last_vblank_wait, DRM_MEM_VBLANK); 336 drm_free(dev->vblank_inmodeset, DRM_MEM_VBLANK); 337 drm_free(dev->_vblank_time, DRM_MEM_VBLANK); 338 339 dev->num_crtcs = 0; 340 } 341 EXPORT_SYMBOL(drm_vblank_cleanup); 342 343 int drm_vblank_init(struct drm_device *dev, int num_crtcs) 344 { 345 int i; 346 347 setup_timer(&dev->vblank_disable_timer, vblank_disable_fn, 348 (unsigned long)dev); 349 lockinit(&dev->vblank_time_lock, "drmvtl", 0, LK_CANRECURSE); 350 351 dev->num_crtcs = num_crtcs; 352 353 dev->vbl_queue = kmalloc(sizeof(wait_queue_head_t) * num_crtcs, 354 DRM_MEM_VBLANK, M_WAITOK); 355 356 dev->_vblank_count = kmalloc(sizeof(atomic_t) * num_crtcs, 357 DRM_MEM_VBLANK, M_WAITOK); 358 dev->vblank_refcount = kmalloc(sizeof(atomic_t) * num_crtcs, 359 DRM_MEM_VBLANK, M_WAITOK); 360 dev->vblank_enabled = kmalloc(num_crtcs * sizeof(int), 361 DRM_MEM_VBLANK, M_WAITOK | M_ZERO); 362 dev->last_vblank = kmalloc(num_crtcs * sizeof(u32), 363 DRM_MEM_VBLANK, M_WAITOK | M_ZERO); 364 dev->last_vblank_wait = kmalloc(num_crtcs * sizeof(u32), 365 DRM_MEM_VBLANK, M_WAITOK | M_ZERO); 366 dev->vblank_inmodeset = kmalloc(num_crtcs * sizeof(int), 367 DRM_MEM_VBLANK, M_WAITOK | M_ZERO); 368 dev->_vblank_time = kmalloc(num_crtcs * DRM_VBLANKTIME_RBSIZE * 369 sizeof(struct timeval), DRM_MEM_VBLANK, M_WAITOK | M_ZERO); 370 DRM_INFO("Supports vblank timestamp caching Rev 1 (10.10.2010).\n"); 371 372 /* Driver specific high-precision vblank timestamping supported? */ 373 if (dev->driver->get_vblank_timestamp) 374 DRM_INFO("Driver supports precise vblank timestamp query.\n"); 375 else 376 DRM_INFO("No driver support for vblank timestamp query.\n"); 377 378 /* Zero per-crtc vblank stuff */ 379 for (i = 0; i < num_crtcs; i++) { 380 init_waitqueue_head(&dev->vbl_queue[i]); 381 atomic_set(&dev->_vblank_count[i], 0); 382 atomic_set(&dev->vblank_refcount[i], 0); 383 } 384 385 dev->vblank_disable_allowed = 0; 386 return 0; 387 } 388 EXPORT_SYMBOL(drm_vblank_init); 389 390 void 391 drm_calc_timestamping_constants(struct drm_crtc *crtc) 392 { 393 int64_t linedur_ns = 0, pixeldur_ns = 0, framedur_ns = 0; 394 uint64_t dotclock; 395 396 /* Dot clock in Hz: */ 397 dotclock = (uint64_t) crtc->hwmode.clock * 1000; 398 399 /* Fields of interlaced scanout modes are only halve a frame duration. 400 * Double the dotclock to get halve the frame-/line-/pixelduration. 401 */ 402 if (crtc->hwmode.flags & DRM_MODE_FLAG_INTERLACE) 403 dotclock *= 2; 404 405 /* Valid dotclock? */ 406 if (dotclock > 0) { 407 /* Convert scanline length in pixels and video dot clock to 408 * line duration, frame duration and pixel duration in 409 * nanoseconds: 410 */ 411 pixeldur_ns = (int64_t)1000000000 / dotclock; 412 linedur_ns = ((uint64_t)crtc->hwmode.crtc_htotal * 413 1000000000) / dotclock; 414 framedur_ns = (int64_t)crtc->hwmode.crtc_vtotal * linedur_ns; 415 } else 416 DRM_ERROR("crtc %d: Can't calculate constants, dotclock = 0!\n", 417 crtc->base.id); 418 419 crtc->pixeldur_ns = pixeldur_ns; 420 crtc->linedur_ns = linedur_ns; 421 crtc->framedur_ns = framedur_ns; 422 423 DRM_DEBUG("crtc %d: hwmode: htotal %d, vtotal %d, vdisplay %d\n", 424 crtc->base.id, crtc->hwmode.crtc_htotal, 425 crtc->hwmode.crtc_vtotal, crtc->hwmode.crtc_vdisplay); 426 DRM_DEBUG("crtc %d: clock %d kHz framedur %d linedur %d, pixeldur %d\n", 427 crtc->base.id, (int) dotclock/1000, (int) framedur_ns, 428 (int) linedur_ns, (int) pixeldur_ns); 429 } 430 431 /** 432 * drm_calc_vbltimestamp_from_scanoutpos - helper routine for kms 433 * drivers. Implements calculation of exact vblank timestamps from 434 * given drm_display_mode timings and current video scanout position 435 * of a crtc. This can be called from within get_vblank_timestamp() 436 * implementation of a kms driver to implement the actual timestamping. 437 * 438 * Should return timestamps conforming to the OML_sync_control OpenML 439 * extension specification. The timestamp corresponds to the end of 440 * the vblank interval, aka start of scanout of topmost-leftmost display 441 * pixel in the following video frame. 442 * 443 * Requires support for optional dev->driver->get_scanout_position() 444 * in kms driver, plus a bit of setup code to provide a drm_display_mode 445 * that corresponds to the true scanout timing. 446 * 447 * The current implementation only handles standard video modes. It 448 * returns as no operation if a doublescan or interlaced video mode is 449 * active. Higher level code is expected to handle this. 450 * 451 * @dev: DRM device. 452 * @crtc: Which crtc's vblank timestamp to retrieve. 453 * @max_error: Desired maximum allowable error in timestamps (nanosecs). 454 * On return contains true maximum error of timestamp. 455 * @vblank_time: Pointer to struct timeval which should receive the timestamp. 456 * @flags: Flags to pass to driver: 457 * 0 = Default. 458 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler. 459 * @refcrtc: drm_crtc* of crtc which defines scanout timing. 460 * 461 * Returns negative value on error, failure or if not supported in current 462 * video mode: 463 * 464 * -EINVAL - Invalid crtc. 465 * -EAGAIN - Temporary unavailable, e.g., called before initial modeset. 466 * -ENOTSUPP - Function not supported in current display mode. 467 * -EIO - Failed, e.g., due to failed scanout position query. 468 * 469 * Returns or'ed positive status flags on success: 470 * 471 * DRM_VBLANKTIME_SCANOUTPOS_METHOD - Signal this method used for timestamping. 472 * DRM_VBLANKTIME_INVBL - Timestamp taken while scanout was in vblank interval. 473 * 474 */ 475 int 476 drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc, 477 int *max_error, struct timeval *vblank_time, unsigned flags, 478 struct drm_crtc *refcrtc) 479 { 480 struct timeval stime, raw_time; 481 struct drm_display_mode *mode; 482 int vbl_status, vtotal, vdisplay; 483 int vpos, hpos, i; 484 int64_t framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns; 485 bool invbl; 486 487 if (crtc < 0 || crtc >= dev->num_crtcs) { 488 DRM_ERROR("Invalid crtc %d\n", crtc); 489 return -EINVAL; 490 } 491 492 /* Scanout position query not supported? Should not happen. */ 493 if (!dev->driver->get_scanout_position) { 494 DRM_ERROR("Called from driver w/o get_scanout_position()!?\n"); 495 return -EIO; 496 } 497 498 mode = &refcrtc->hwmode; 499 vtotal = mode->crtc_vtotal; 500 vdisplay = mode->crtc_vdisplay; 501 502 /* Durations of frames, lines, pixels in nanoseconds. */ 503 framedur_ns = refcrtc->framedur_ns; 504 linedur_ns = refcrtc->linedur_ns; 505 pixeldur_ns = refcrtc->pixeldur_ns; 506 507 /* If mode timing undefined, just return as no-op: 508 * Happens during initial modesetting of a crtc. 509 */ 510 if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) { 511 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc); 512 return -EAGAIN; 513 } 514 515 /* Get current scanout position with system timestamp. 516 * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times 517 * if single query takes longer than max_error nanoseconds. 518 * 519 * This guarantees a tight bound on maximum error if 520 * code gets preempted or delayed for some reason. 521 */ 522 for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) { 523 /* Disable preemption to make it very likely to 524 * succeed in the first iteration. 525 */ 526 crit_enter(); 527 528 /* Get system timestamp before query. */ 529 getmicrouptime(&stime); 530 531 /* Get vertical and horizontal scanout pos. vpos, hpos. */ 532 vbl_status = dev->driver->get_scanout_position(dev, crtc, &vpos, &hpos); 533 534 /* Get system timestamp after query. */ 535 getmicrouptime(&raw_time); 536 537 crit_exit(); 538 539 /* Return as no-op if scanout query unsupported or failed. */ 540 if (!(vbl_status & DRM_SCANOUTPOS_VALID)) { 541 DRM_DEBUG("crtc %d : scanoutpos query failed [%d].\n", 542 crtc, vbl_status); 543 return -EIO; 544 } 545 546 duration_ns = timeval_to_ns(&raw_time) - timeval_to_ns(&stime); 547 548 /* Accept result with < max_error nsecs timing uncertainty. */ 549 if (duration_ns <= (int64_t) *max_error) 550 break; 551 } 552 553 /* Noisy system timing? */ 554 if (i == DRM_TIMESTAMP_MAXRETRIES) { 555 DRM_DEBUG("crtc %d: Noisy timestamp %d us > %d us [%d reps].\n", 556 crtc, (int) duration_ns/1000, *max_error/1000, i); 557 } 558 559 /* Return upper bound of timestamp precision error. */ 560 *max_error = (int) duration_ns; 561 562 /* Check if in vblank area: 563 * vpos is >=0 in video scanout area, but negative 564 * within vblank area, counting down the number of lines until 565 * start of scanout. 566 */ 567 invbl = vbl_status & DRM_SCANOUTPOS_INVBL; 568 569 /* Convert scanout position into elapsed time at raw_time query 570 * since start of scanout at first display scanline. delta_ns 571 * can be negative if start of scanout hasn't happened yet. 572 */ 573 delta_ns = (int64_t)vpos * linedur_ns + (int64_t)hpos * pixeldur_ns; 574 575 /* Is vpos outside nominal vblank area, but less than 576 * 1/100 of a frame height away from start of vblank? 577 * If so, assume this isn't a massively delayed vblank 578 * interrupt, but a vblank interrupt that fired a few 579 * microseconds before true start of vblank. Compensate 580 * by adding a full frame duration to the final timestamp. 581 * Happens, e.g., on ATI R500, R600. 582 * 583 * We only do this if DRM_CALLED_FROM_VBLIRQ. 584 */ 585 if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl && 586 ((vdisplay - vpos) < vtotal / 100)) { 587 delta_ns = delta_ns - framedur_ns; 588 589 /* Signal this correction as "applied". */ 590 vbl_status |= 0x8; 591 } 592 593 /* Subtract time delta from raw timestamp to get final 594 * vblank_time timestamp for end of vblank. 595 */ 596 *vblank_time = ns_to_timeval(timeval_to_ns(&raw_time) - delta_ns); 597 598 DRM_DEBUG("crtc %d : v %d p(%d,%d)@ %jd.%jd -> %jd.%jd [e %d us, %d rep]\n", 599 crtc, (int)vbl_status, hpos, vpos, (uintmax_t)raw_time.tv_sec, 600 (uintmax_t)raw_time.tv_usec, (uintmax_t)vblank_time->tv_sec, 601 (uintmax_t)vblank_time->tv_usec, (int)duration_ns/1000, i); 602 603 vbl_status = DRM_VBLANKTIME_SCANOUTPOS_METHOD; 604 if (invbl) 605 vbl_status |= DRM_VBLANKTIME_INVBL; 606 607 return vbl_status; 608 } 609 610 static struct timeval get_drm_timestamp(void) 611 { 612 struct timeval now; 613 614 getmicrouptime(&now); 615 616 return now; 617 } 618 619 /** 620 * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent 621 * vblank interval. 622 * 623 * @dev: DRM device 624 * @crtc: which crtc's vblank timestamp to retrieve 625 * @tvblank: Pointer to target struct timeval which should receive the timestamp 626 * @flags: Flags to pass to driver: 627 * 0 = Default. 628 * DRM_CALLED_FROM_VBLIRQ = If function is called from vbl irq handler. 629 * 630 * Fetches the system timestamp corresponding to the time of the most recent 631 * vblank interval on specified crtc. May call into kms-driver to 632 * compute the timestamp with a high-precision GPU specific method. 633 * 634 * Returns zero if timestamp originates from uncorrected do_gettimeofday() 635 * call, i.e., it isn't very precisely locked to the true vblank. 636 * 637 * Returns non-zero if timestamp is considered to be very precise. 638 */ 639 u32 drm_get_last_vbltimestamp(struct drm_device *dev, int crtc, 640 struct timeval *tvblank, unsigned flags) 641 { 642 int ret = 0; 643 644 /* Define requested maximum error on timestamps (nanoseconds). */ 645 int max_error = (int) drm_timestamp_precision * 1000; 646 647 /* Query driver if possible and precision timestamping enabled. */ 648 if (dev->driver->get_vblank_timestamp && (max_error > 0)) { 649 ret = dev->driver->get_vblank_timestamp(dev, crtc, &max_error, 650 tvblank, flags); 651 if (ret > 0) 652 return (u32) ret; 653 } 654 655 /* GPU high precision timestamp query unsupported or failed. 656 * Return gettimeofday timestamp as best estimate. 657 */ 658 microtime(tvblank); 659 660 return 0; 661 } 662 663 /** 664 * drm_vblank_count - retrieve "cooked" vblank counter value 665 * @dev: DRM device 666 * @crtc: which counter to retrieve 667 * 668 * Fetches the "cooked" vblank count value that represents the number of 669 * vblank events since the system was booted, including lost events due to 670 * modesetting activity. 671 */ 672 u32 drm_vblank_count(struct drm_device *dev, int crtc) 673 { 674 return atomic_read(&dev->_vblank_count[crtc]); 675 } 676 677 /** 678 * drm_vblank_count_and_time - retrieve "cooked" vblank counter value 679 * and the system timestamp corresponding to that vblank counter value. 680 * 681 * @dev: DRM device 682 * @crtc: which counter to retrieve 683 * @vblanktime: Pointer to struct timeval to receive the vblank timestamp. 684 * 685 * Fetches the "cooked" vblank count value that represents the number of 686 * vblank events since the system was booted, including lost events due to 687 * modesetting activity. Returns corresponding system timestamp of the time 688 * of the vblank interval that corresponds to the current value vblank counter 689 * value. 690 */ 691 u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc, 692 struct timeval *vblanktime) 693 { 694 u32 cur_vblank; 695 696 /* Read timestamp from slot of _vblank_time ringbuffer 697 * that corresponds to current vblank count. Retry if 698 * count has incremented during readout. This works like 699 * a seqlock. 700 */ 701 do { 702 cur_vblank = atomic_read(&dev->_vblank_count[crtc]); 703 *vblanktime = vblanktimestamp(dev, crtc, cur_vblank); 704 cpu_lfence(); 705 } while (cur_vblank != atomic_read(&dev->_vblank_count[crtc])); 706 707 return cur_vblank; 708 } 709 710 static void send_vblank_event(struct drm_device *dev, 711 struct drm_pending_vblank_event *e, 712 unsigned long seq, struct timeval *now) 713 { 714 KKASSERT(mutex_is_locked(&dev->event_lock)); 715 e->event.sequence = seq; 716 e->event.tv_sec = now->tv_sec; 717 e->event.tv_usec = now->tv_usec; 718 719 list_add_tail(&e->base.link, 720 &e->base.file_priv->event_list); 721 wakeup(&e->base.file_priv->event_list); 722 #if 0 723 trace_drm_vblank_event_delivered(e->base.pid, e->pipe, 724 e->event.sequence); 725 #endif 726 } 727 728 /** 729 * drm_send_vblank_event - helper to send vblank event after pageflip 730 * @dev: DRM device 731 * @crtc: CRTC in question 732 * @e: the event to send 733 * 734 * Updates sequence # and timestamp on event, and sends it to userspace. 735 * Caller must hold event lock. 736 */ 737 void drm_send_vblank_event(struct drm_device *dev, int crtc, 738 struct drm_pending_vblank_event *e) 739 { 740 struct timeval now; 741 unsigned int seq; 742 if (crtc >= 0) { 743 seq = drm_vblank_count_and_time(dev, crtc, &now); 744 } else { 745 seq = 0; 746 747 now = get_drm_timestamp(); 748 } 749 e->pipe = crtc; 750 send_vblank_event(dev, e, seq, &now); 751 } 752 EXPORT_SYMBOL(drm_send_vblank_event); 753 754 /** 755 * drm_update_vblank_count - update the master vblank counter 756 * @dev: DRM device 757 * @crtc: counter to update 758 * 759 * Call back into the driver to update the appropriate vblank counter 760 * (specified by @crtc). Deal with wraparound, if it occurred, and 761 * update the last read value so we can deal with wraparound on the next 762 * call if necessary. 763 * 764 * Only necessary when going from off->on, to account for frames we 765 * didn't get an interrupt for. 766 * 767 * Note: caller must hold dev->vbl_lock since this reads & writes 768 * device vblank fields. 769 */ 770 static void drm_update_vblank_count(struct drm_device *dev, int crtc) 771 { 772 u32 cur_vblank, diff, tslot, rc; 773 struct timeval t_vblank; 774 775 /* 776 * Interrupts were disabled prior to this call, so deal with counter 777 * wrap if needed. 778 * NOTE! It's possible we lost a full dev->max_vblank_count events 779 * here if the register is small or we had vblank interrupts off for 780 * a long time. 781 * 782 * We repeat the hardware vblank counter & timestamp query until 783 * we get consistent results. This to prevent races between gpu 784 * updating its hardware counter while we are retrieving the 785 * corresponding vblank timestamp. 786 */ 787 do { 788 cur_vblank = dev->driver->get_vblank_counter(dev, crtc); 789 rc = drm_get_last_vbltimestamp(dev, crtc, &t_vblank, 0); 790 } while (cur_vblank != dev->driver->get_vblank_counter(dev, crtc)); 791 792 /* Deal with counter wrap */ 793 diff = cur_vblank - dev->last_vblank[crtc]; 794 if (cur_vblank < dev->last_vblank[crtc]) { 795 diff += dev->max_vblank_count; 796 797 DRM_DEBUG("last_vblank[%d]=0x%x, cur_vblank=0x%x => diff=0x%x\n", 798 crtc, dev->last_vblank[crtc], cur_vblank, diff); 799 } 800 801 DRM_DEBUG("enabling vblank interrupts on crtc %d, missed %d\n", 802 crtc, diff); 803 804 /* Reinitialize corresponding vblank timestamp if high-precision query 805 * available. Skip this step if query unsupported or failed. Will 806 * reinitialize delayed at next vblank interrupt in that case. 807 */ 808 if (rc) { 809 tslot = atomic_read(&dev->_vblank_count[crtc]) + diff; 810 vblanktimestamp(dev, crtc, tslot) = t_vblank; 811 } 812 813 atomic_add(diff, &dev->_vblank_count[crtc]); 814 } 815 816 /** 817 * drm_vblank_get - get a reference count on vblank events 818 * @dev: DRM device 819 * @crtc: which CRTC to own 820 * 821 * Acquire a reference count on vblank events to avoid having them disabled 822 * while in use. 823 * 824 * RETURNS 825 * Zero on success, nonzero on failure. 826 */ 827 int drm_vblank_get(struct drm_device *dev, int crtc) 828 { 829 int ret = 0; 830 831 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE); 832 /* Going from 0->1 means we have to enable interrupts again */ 833 if (atomic_add_return(1, &dev->vblank_refcount[crtc]) == 1) { 834 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE); 835 if (!dev->vblank_enabled[crtc]) { 836 /* Enable vblank irqs under vblank_time_lock protection. 837 * All vblank count & timestamp updates are held off 838 * until we are done reinitializing master counter and 839 * timestamps. Filtercode in drm_handle_vblank() will 840 * prevent double-accounting of same vblank interval. 841 */ 842 ret = -dev->driver->enable_vblank(dev, crtc); 843 DRM_DEBUG("enabling vblank on crtc %d, ret: %d\n", 844 crtc, ret); 845 if (ret) 846 atomic_dec(&dev->vblank_refcount[crtc]); 847 else { 848 dev->vblank_enabled[crtc] = 1; 849 drm_update_vblank_count(dev, crtc); 850 } 851 } 852 lockmgr(&dev->vblank_time_lock, LK_RELEASE); 853 } else { 854 if (!dev->vblank_enabled[crtc]) { 855 atomic_dec(&dev->vblank_refcount[crtc]); 856 ret = EINVAL; 857 } 858 } 859 lockmgr(&dev->vbl_lock, LK_RELEASE); 860 861 return ret; 862 } 863 864 /** 865 * drm_vblank_put - give up ownership of vblank events 866 * @dev: DRM device 867 * @crtc: which counter to give up 868 * 869 * Release ownership of a given vblank counter, turning off interrupts 870 * if possible. Disable interrupts after drm_vblank_offdelay milliseconds. 871 */ 872 void drm_vblank_put(struct drm_device *dev, int crtc) 873 { 874 BUG_ON(atomic_read(&dev->vblank_refcount[crtc]) == 0); 875 876 /* Last user schedules interrupt disable */ 877 if (atomic_dec_and_test(&dev->vblank_refcount[crtc]) && 878 (drm_vblank_offdelay > 0)) 879 mod_timer(&dev->vblank_disable_timer, 880 jiffies + ((drm_vblank_offdelay * DRM_HZ)/1000)); 881 } 882 EXPORT_SYMBOL(drm_vblank_put); 883 884 void drm_vblank_off(struct drm_device *dev, int crtc) 885 { 886 struct drm_pending_vblank_event *e, *t; 887 struct timeval now; 888 unsigned int seq; 889 890 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE); 891 vblank_disable_and_save(dev, crtc); 892 lockmgr(&dev->event_lock, LK_EXCLUSIVE); 893 wakeup(&dev->_vblank_count[crtc]); 894 895 /* Send any queued vblank events, lest the natives grow disquiet */ 896 seq = drm_vblank_count_and_time(dev, crtc, &now); 897 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) { 898 if (e->pipe != crtc) 899 continue; 900 DRM_DEBUG("Sending premature vblank event on disable: \ 901 wanted %d, current %d\n", 902 e->event.sequence, seq); 903 list_del(&e->base.link); 904 drm_vblank_put(dev, e->pipe); 905 send_vblank_event(dev, e, seq, &now); 906 } 907 908 lockmgr(&dev->event_lock, LK_RELEASE); 909 lockmgr(&dev->vbl_lock, LK_RELEASE); 910 } 911 912 /** 913 * drm_vblank_pre_modeset - account for vblanks across mode sets 914 * @dev: DRM device 915 * @crtc: CRTC in question 916 * @post: post or pre mode set? 917 * 918 * Account for vblank events across mode setting events, which will likely 919 * reset the hardware frame counter. 920 */ 921 void drm_vblank_pre_modeset(struct drm_device *dev, int crtc) 922 { 923 /* vblank is not initialized (IRQ not installed ?) */ 924 if (!dev->num_crtcs) 925 return; 926 /* 927 * To avoid all the problems that might happen if interrupts 928 * were enabled/disabled around or between these calls, we just 929 * have the kernel take a reference on the CRTC (just once though 930 * to avoid corrupting the count if multiple, mismatch calls occur), 931 * so that interrupts remain enabled in the interim. 932 */ 933 if (!dev->vblank_inmodeset[crtc]) { 934 dev->vblank_inmodeset[crtc] = 0x1; 935 if (drm_vblank_get(dev, crtc) == 0) 936 dev->vblank_inmodeset[crtc] |= 0x2; 937 } 938 } 939 940 void drm_vblank_post_modeset(struct drm_device *dev, int crtc) 941 { 942 943 if (dev->vblank_inmodeset[crtc]) { 944 lockmgr(&dev->vbl_lock, LK_EXCLUSIVE); 945 dev->vblank_disable_allowed = 1; 946 lockmgr(&dev->vbl_lock, LK_RELEASE); 947 948 if (dev->vblank_inmodeset[crtc] & 0x2) 949 drm_vblank_put(dev, crtc); 950 951 dev->vblank_inmodeset[crtc] = 0; 952 } 953 } 954 955 /** 956 * drm_modeset_ctl - handle vblank event counter changes across mode switch 957 * @DRM_IOCTL_ARGS: standard ioctl arguments 958 * 959 * Applications should call the %_DRM_PRE_MODESET and %_DRM_POST_MODESET 960 * ioctls around modesetting so that any lost vblank events are accounted for. 961 * 962 * Generally the counter will reset across mode sets. If interrupts are 963 * enabled around this call, we don't have to do anything since the counter 964 * will have already been incremented. 965 */ 966 int drm_modeset_ctl(struct drm_device *dev, void *data, 967 struct drm_file *file_priv) 968 { 969 struct drm_modeset_ctl *modeset = data; 970 int ret = 0; 971 unsigned int crtc; 972 973 /* If drm_vblank_init() hasn't been called yet, just no-op */ 974 if (!dev->num_crtcs) 975 goto out; 976 977 crtc = modeset->crtc; 978 if (crtc >= dev->num_crtcs) { 979 ret = -EINVAL; 980 goto out; 981 } 982 983 switch (modeset->cmd) { 984 case _DRM_PRE_MODESET: 985 drm_vblank_pre_modeset(dev, crtc); 986 break; 987 case _DRM_POST_MODESET: 988 drm_vblank_post_modeset(dev, crtc); 989 break; 990 default: 991 ret = -EINVAL; 992 break; 993 } 994 995 out: 996 return ret; 997 } 998 999 static void 1000 drm_vblank_event_destroy(struct drm_pending_event *e) 1001 { 1002 1003 drm_free(e, DRM_MEM_VBLANK); 1004 } 1005 1006 static int drm_queue_vblank_event(struct drm_device *dev, int pipe, 1007 union drm_wait_vblank *vblwait, 1008 struct drm_file *file_priv) 1009 { 1010 struct drm_pending_vblank_event *e; 1011 struct timeval now; 1012 unsigned int seq; 1013 int ret; 1014 1015 e = kmalloc(sizeof *e, DRM_MEM_VBLANK, M_WAITOK | M_ZERO); 1016 1017 e->pipe = pipe; 1018 e->base.pid = curproc->p_pid; 1019 e->event.base.type = DRM_EVENT_VBLANK; 1020 e->event.base.length = sizeof e->event; 1021 e->event.user_data = vblwait->request.signal; 1022 e->base.event = &e->event.base; 1023 e->base.file_priv = file_priv; 1024 e->base.destroy = drm_vblank_event_destroy; 1025 1026 lockmgr(&dev->event_lock, LK_EXCLUSIVE); 1027 1028 if (file_priv->event_space < sizeof e->event) { 1029 ret = EBUSY; 1030 goto err_unlock; 1031 } 1032 1033 file_priv->event_space -= sizeof e->event; 1034 seq = drm_vblank_count_and_time(dev, pipe, &now); 1035 1036 if ((vblwait->request.type & _DRM_VBLANK_NEXTONMISS) && 1037 (seq - vblwait->request.sequence) <= (1 << 23)) { 1038 vblwait->request.sequence = seq + 1; 1039 vblwait->reply.sequence = vblwait->request.sequence; 1040 } 1041 1042 DRM_DEBUG("event on vblank count %d, current %d, crtc %d\n", 1043 vblwait->request.sequence, seq, pipe); 1044 1045 e->event.sequence = vblwait->request.sequence; 1046 if ((seq - vblwait->request.sequence) <= (1 << 23)) { 1047 drm_vblank_put(dev, pipe); 1048 send_vblank_event(dev, e, seq, &now); 1049 vblwait->reply.sequence = seq; 1050 } else { 1051 /* drm_handle_vblank_events will call drm_vblank_put */ 1052 list_add_tail(&e->base.link, &dev->vblank_event_list); 1053 vblwait->reply.sequence = vblwait->request.sequence; 1054 } 1055 1056 lockmgr(&dev->event_lock, LK_RELEASE); 1057 1058 return 0; 1059 1060 err_unlock: 1061 lockmgr(&dev->event_lock, LK_RELEASE); 1062 drm_free(e, DRM_MEM_VBLANK); 1063 drm_vblank_put(dev, pipe); 1064 return ret; 1065 } 1066 1067 /** 1068 * Wait for VBLANK. 1069 * 1070 * \param inode device inode. 1071 * \param file_priv DRM file private. 1072 * \param cmd command. 1073 * \param data user argument, pointing to a drm_wait_vblank structure. 1074 * \return zero on success or a negative number on failure. 1075 * 1076 * This function enables the vblank interrupt on the pipe requested, then 1077 * sleeps waiting for the requested sequence number to occur, and drops 1078 * the vblank interrupt refcount afterwards. (vblank irq disable follows that 1079 * after a timeout with no further vblank waits scheduled). 1080 */ 1081 int drm_wait_vblank(struct drm_device *dev, void *data, 1082 struct drm_file *file_priv) 1083 { 1084 union drm_wait_vblank *vblwait = data; 1085 int ret = 0; 1086 unsigned int flags, seq, crtc, high_crtc; 1087 1088 if (/*(!drm_dev_to_irq(dev)) || */(!dev->irq_enabled)) 1089 return (EINVAL); 1090 1091 if (vblwait->request.type & _DRM_VBLANK_SIGNAL) 1092 return (EINVAL); 1093 1094 if (vblwait->request.type & 1095 ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK | 1096 _DRM_VBLANK_HIGH_CRTC_MASK)) { 1097 DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n", 1098 vblwait->request.type, 1099 (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK | 1100 _DRM_VBLANK_HIGH_CRTC_MASK)); 1101 return (EINVAL); 1102 } 1103 1104 flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK; 1105 high_crtc = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK); 1106 if (high_crtc) 1107 crtc = high_crtc >> _DRM_VBLANK_HIGH_CRTC_SHIFT; 1108 else 1109 crtc = flags & _DRM_VBLANK_SECONDARY ? 1 : 0; 1110 if (crtc >= dev->num_crtcs) 1111 return (EINVAL); 1112 1113 ret = drm_vblank_get(dev, crtc); 1114 if (ret) { 1115 DRM_DEBUG("failed to acquire vblank counter, %d\n", ret); 1116 return (ret); 1117 } 1118 seq = drm_vblank_count(dev, crtc); 1119 1120 switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) { 1121 case _DRM_VBLANK_RELATIVE: 1122 vblwait->request.sequence += seq; 1123 vblwait->request.type &= ~_DRM_VBLANK_RELATIVE; 1124 case _DRM_VBLANK_ABSOLUTE: 1125 break; 1126 default: 1127 ret = (EINVAL); 1128 goto done; 1129 } 1130 1131 if (flags & _DRM_VBLANK_EVENT) { 1132 /* must hold on to the vblank ref until the event fires 1133 * drm_vblank_put will be called asynchronously 1134 */ 1135 return drm_queue_vblank_event(dev, crtc, vblwait, file_priv); 1136 } 1137 1138 if ((flags & _DRM_VBLANK_NEXTONMISS) && 1139 (seq - vblwait->request.sequence) <= (1<<23)) { 1140 vblwait->request.sequence = seq + 1; 1141 } 1142 1143 dev->last_vblank_wait[crtc] = vblwait->request.sequence; 1144 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE); 1145 while (((drm_vblank_count(dev, crtc) - vblwait->request.sequence) > 1146 (1 << 23)) && dev->irq_enabled) { 1147 /* 1148 * The wakeups from the drm_irq_uninstall() and 1149 * drm_vblank_off() may be lost there since vbl_lock 1150 * is not held. Then, the timeout will wake us; the 3 1151 * seconds delay should not be a problem for 1152 * application when crtc is disabled or irq 1153 * uninstalled anyway. 1154 */ 1155 ret = lksleep(&dev->_vblank_count[crtc], &dev->vblank_time_lock, 1156 PCATCH, "drmvbl", 3 * hz); 1157 if (ret != 0) 1158 break; 1159 } 1160 lockmgr(&dev->vblank_time_lock, LK_RELEASE); 1161 if (ret != EINTR) { 1162 struct timeval now; 1163 long reply_seq; 1164 1165 reply_seq = drm_vblank_count_and_time(dev, crtc, &now); 1166 vblwait->reply.sequence = reply_seq; 1167 vblwait->reply.tval_sec = now.tv_sec; 1168 vblwait->reply.tval_usec = now.tv_usec; 1169 } 1170 1171 done: 1172 drm_vblank_put(dev, crtc); 1173 return ret; 1174 } 1175 1176 void drm_handle_vblank_events(struct drm_device *dev, int crtc) 1177 { 1178 struct drm_pending_vblank_event *e, *t; 1179 struct timeval now; 1180 unsigned int seq; 1181 1182 seq = drm_vblank_count_and_time(dev, crtc, &now); 1183 1184 lockmgr(&dev->event_lock, LK_EXCLUSIVE); 1185 1186 list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) { 1187 if (e->pipe != crtc) 1188 continue; 1189 if ((seq - e->event.sequence) > (1<<23)) 1190 continue; 1191 1192 DRM_DEBUG("vblank event on %d, current %d\n", 1193 e->event.sequence, seq); 1194 1195 list_del(&e->base.link); 1196 drm_vblank_put(dev, e->pipe); 1197 send_vblank_event(dev, e, seq, &now); 1198 } 1199 1200 lockmgr(&dev->event_lock, LK_RELEASE); 1201 } 1202 1203 /** 1204 * drm_handle_vblank - handle a vblank event 1205 * @dev: DRM device 1206 * @crtc: where this event occurred 1207 * 1208 * Drivers should call this routine in their vblank interrupt handlers to 1209 * update the vblank counter and send any signals that may be pending. 1210 */ 1211 bool drm_handle_vblank(struct drm_device *dev, int crtc) 1212 { 1213 u32 vblcount; 1214 int64_t diff_ns; 1215 struct timeval tvblank; 1216 1217 if (!dev->num_crtcs) 1218 return false; 1219 1220 /* Need timestamp lock to prevent concurrent execution with 1221 * vblank enable/disable, as this would cause inconsistent 1222 * or corrupted timestamps and vblank counts. 1223 */ 1224 lockmgr(&dev->vblank_time_lock, LK_EXCLUSIVE); 1225 1226 /* Vblank irq handling disabled. Nothing to do. */ 1227 if (!dev->vblank_enabled[crtc]) { 1228 lockmgr(&dev->vblank_time_lock, LK_RELEASE); 1229 return false; 1230 } 1231 1232 /* Fetch corresponding timestamp for this vblank interval from 1233 * driver and store it in proper slot of timestamp ringbuffer. 1234 */ 1235 1236 /* Get current timestamp and count. */ 1237 vblcount = atomic_read(&dev->_vblank_count[crtc]); 1238 drm_get_last_vbltimestamp(dev, crtc, &tvblank, DRM_CALLED_FROM_VBLIRQ); 1239 1240 /* Compute time difference to timestamp of last vblank */ 1241 diff_ns = timeval_to_ns(&tvblank) - 1242 timeval_to_ns(&vblanktimestamp(dev, crtc, vblcount)); 1243 1244 /* Update vblank timestamp and count if at least 1245 * DRM_REDUNDANT_VBLIRQ_THRESH_NS nanoseconds 1246 * difference between last stored timestamp and current 1247 * timestamp. A smaller difference means basically 1248 * identical timestamps. Happens if this vblank has 1249 * been already processed and this is a redundant call, 1250 * e.g., due to spurious vblank interrupts. We need to 1251 * ignore those for accounting. 1252 */ 1253 if (abs64(diff_ns) > DRM_REDUNDANT_VBLIRQ_THRESH_NS) { 1254 /* Store new timestamp in ringbuffer. */ 1255 vblanktimestamp(dev, crtc, vblcount + 1) = tvblank; 1256 1257 /* Increment cooked vblank count. This also atomically commits 1258 * the timestamp computed above. 1259 */ 1260 atomic_inc(&dev->_vblank_count[crtc]); 1261 } else { 1262 DRM_DEBUG("crtc %d: Redundant vblirq ignored. diff_ns = %d\n", 1263 crtc, (int) diff_ns); 1264 } 1265 1266 wakeup(&dev->_vblank_count[crtc]); 1267 drm_handle_vblank_events(dev, crtc); 1268 1269 lockmgr(&dev->vblank_time_lock, LK_RELEASE); 1270 return true; 1271 } 1272