drivers/gpu/drm/i915/intel_crt.c

   1 /*
   2  * Copyright © 2006-2007 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *      Eric Anholt <eric@anholt.net>
  25  */
  26
  27 #include <linux/i2c.h>
  28 #include <linux/slab.h>
  29 #include "drmP.h"
  30 #include "drm.h"
  31 #include "drm_crtc.h"
  32 #include "drm_crtc_helper.h"
  33 #include "drm_edid.h"
  34 #include "intel_drv.h"
  35 #include "i915_drm.h"
  36 #include "i915_drv.h"
  37
  38 /* Here's the desired hotplug mode */
  39 #define ADPA_HOTPLUG_BITS (ADPA_CRT_HOTPLUG_PERIOD_128 |                \
  40                            ADPA_CRT_HOTPLUG_WARMUP_10MS |               \
  41                            ADPA_CRT_HOTPLUG_SAMPLE_4S |                 \
  42                            ADPA_CRT_HOTPLUG_VOLTAGE_50 |                \
  43                            ADPA_CRT_HOTPLUG_VOLREF_325MV |              \
  44                            ADPA_CRT_HOTPLUG_ENABLE)
  45
  46 struct intel_crt {
  47         struct intel_encoder base;
  48         bool force_hotplug_required;
  49 };
  50
  51 static struct intel_crt *intel_attached_crt(struct drm_connector *connector)
  52 {
  53         return container_of(intel_attached_encoder(connector),
  54                             struct intel_crt, base);
  55 }
  56
  57 static void intel_crt_dpms(struct drm_encoder *encoder, int mode)
  58 {
  59         struct drm_device *dev = encoder->dev;
  60         struct drm_i915_private *dev_priv = dev->dev_private;
  61         u32 temp, reg;
  62
  63         if (HAS_PCH_SPLIT(dev))
  64                 reg = PCH_ADPA;
  65         else
  66                 reg = ADPA;
  67
  68         temp = I915_READ(reg);
  69         temp &= ~(ADPA_HSYNC_CNTL_DISABLE | ADPA_VSYNC_CNTL_DISABLE);
  70         temp &= ~ADPA_DAC_ENABLE;
  71
  72         switch(mode) {
  73         case DRM_MODE_DPMS_ON:
  74                 temp |= ADPA_DAC_ENABLE;
  75                 break;
  76         case DRM_MODE_DPMS_STANDBY:
  77                 temp |= ADPA_DAC_ENABLE | ADPA_HSYNC_CNTL_DISABLE;
  78                 break;
  79         case DRM_MODE_DPMS_SUSPEND:
  80                 temp |= ADPA_DAC_ENABLE | ADPA_VSYNC_CNTL_DISABLE;
  81                 break;
  82         case DRM_MODE_DPMS_OFF:
  83                 temp |= ADPA_HSYNC_CNTL_DISABLE | ADPA_VSYNC_CNTL_DISABLE;
  84                 break;
  85         }
  86
  87         I915_WRITE(reg, temp);
  88 }
  89
  90 static int intel_crt_mode_valid(struct drm_connector *connector,
  91                                 struct drm_display_mode *mode)
  92 {
  93         struct drm_device *dev = connector->dev;
  94
  95         int max_clock = 0;
  96         if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
  97                 return MODE_NO_DBLESCAN;
  98
  99         if (mode->clock < 25000)
 100                 return MODE_CLOCK_LOW;
 101
 102         if (IS_GEN2(dev))
 103                 max_clock = 350000;
 104         else
 105                 max_clock = 400000;
 106         if (mode->clock > max_clock)
 107                 return MODE_CLOCK_HIGH;
 108
 109         return MODE_OK;
 110 }
 111
 112 static bool intel_crt_mode_fixup(struct drm_encoder *encoder,
 113                                  struct drm_display_mode *mode,
 114                                  struct drm_display_mode *adjusted_mode)
 115 {
 116         return true;
 117 }
 118
 119 static void intel_crt_mode_set(struct drm_encoder *encoder,
 120                                struct drm_display_mode *mode,
 121                                struct drm_display_mode *adjusted_mode)
 122 {
 123
 124         struct drm_device *dev = encoder->dev;
 125         struct drm_crtc *crtc = encoder->crtc;
 126         struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 127         struct drm_i915_private *dev_priv = dev->dev_private;
 128         int dpll_md_reg;
 129         u32 adpa, dpll_md;
 130         u32 adpa_reg;
 131
 132         dpll_md_reg = DPLL_MD(intel_crtc->pipe);
 133
 134         if (HAS_PCH_SPLIT(dev))
 135                 adpa_reg = PCH_ADPA;
 136         else
 137                 adpa_reg = ADPA;
 138
 139         /*
 140          * Disable separate mode multiplier used when cloning SDVO to CRT
 141          * XXX this needs to be adjusted when we really are cloning
 142          */
 143         if (INTEL_INFO(dev)->gen >= 4 && !HAS_PCH_SPLIT(dev)) {
 144                 dpll_md = I915_READ(dpll_md_reg);
 145                 I915_WRITE(dpll_md_reg,
 146                            dpll_md & ~DPLL_MD_UDI_MULTIPLIER_MASK);
 147         }
 148
 149         adpa = ADPA_HOTPLUG_BITS;
 150         if (adjusted_mode->flags & DRM_MODE_FLAG_PHSYNC)
 151                 adpa |= ADPA_HSYNC_ACTIVE_HIGH;
 152         if (adjusted_mode->flags & DRM_MODE_FLAG_PVSYNC)
 153                 adpa |= ADPA_VSYNC_ACTIVE_HIGH;
 154
 155         if (intel_crtc->pipe == 0) {
 156                 if (HAS_PCH_CPT(dev))
 157                         adpa |= PORT_TRANS_A_SEL_CPT;
 158                 else
 159                         adpa |= ADPA_PIPE_A_SELECT;
 160         } else {
 161                 if (HAS_PCH_CPT(dev))
 162                         adpa |= PORT_TRANS_B_SEL_CPT;
 163                 else
 164                         adpa |= ADPA_PIPE_B_SELECT;
 165         }
 166
 167         if (!HAS_PCH_SPLIT(dev))
 168                 I915_WRITE(BCLRPAT(intel_crtc->pipe), 0);
 169
 170         I915_WRITE(adpa_reg, adpa);
 171 }
 172
 173 static bool intel_ironlake_crt_detect_hotplug(struct drm_connector *connector)
 174 {
 175         struct drm_device *dev = connector->dev;
 176         struct intel_crt *crt = intel_attached_crt(connector);
 177         struct drm_i915_private *dev_priv = dev->dev_private;
 178         u32 adpa;
 179         bool ret;
 180
 181         /* The first time through, trigger an explicit detection cycle */
 182         if (crt->force_hotplug_required) {
 183                 bool turn_off_dac = HAS_PCH_SPLIT(dev);
 184                 u32 save_adpa;
 185
 186                 crt->force_hotplug_required = 0;
 187
 188                 save_adpa = adpa = I915_READ(PCH_ADPA);
 189                 DRM_DEBUG_KMS("trigger hotplug detect cycle: adpa=0x%x\n", adpa);
 190
 191                 adpa |= ADPA_CRT_HOTPLUG_FORCE_TRIGGER;
 192                 if (turn_off_dac)
 193                         adpa &= ~ADPA_DAC_ENABLE;
 194
 195                 I915_WRITE(PCH_ADPA, adpa);
 196
 197                 if (wait_for((I915_READ(PCH_ADPA) & ADPA_CRT_HOTPLUG_FORCE_TRIGGER) == 0,
 198                              1000))
 199                         DRM_DEBUG_KMS("timed out waiting for FORCE_TRIGGER");
 200
 201                 if (turn_off_dac) {
 202                         I915_WRITE(PCH_ADPA, save_adpa);
 203                         POSTING_READ(PCH_ADPA);
 204                 }
 205         }
 206
 207         /* Check the status to see if both blue and green are on now */
 208         adpa = I915_READ(PCH_ADPA);
 209         if ((adpa & ADPA_CRT_HOTPLUG_MONITOR_MASK) != 0)
 210                 ret = true;
 211         else
 212                 ret = false;
 213         DRM_DEBUG_KMS("ironlake hotplug adpa=0x%x, result %d\n", adpa, ret);
 214
 215         return ret;
 216 }
 217
 218 /**
 219  * Uses CRT_HOTPLUG_EN and CRT_HOTPLUG_STAT to detect CRT presence.
 220  *
 221  * Not for i915G/i915GM
 222  *
 223  * \return true if CRT is connected.
 224  * \return false if CRT is disconnected.
 225  */
 226 static bool intel_crt_detect_hotplug(struct drm_connector *connector)
 227 {
 228         struct drm_device *dev = connector->dev;
 229         struct drm_i915_private *dev_priv = dev->dev_private;
 230         u32 hotplug_en, orig, stat;
 231         bool ret = false;
 232         int i, tries = 0;
 233
 234         if (HAS_PCH_SPLIT(dev))
 235                 return intel_ironlake_crt_detect_hotplug(connector);
 236
 237         /*
 238          * On 4 series desktop, CRT detect sequence need to be done twice
 239          * to get a reliable result.
 240          */
 241
 242         if (IS_G4X(dev) && !IS_GM45(dev))
 243                 tries = 2;
 244         else
 245                 tries = 1;
 246         hotplug_en = orig = I915_READ(PORT_HOTPLUG_EN);
 247         hotplug_en |= CRT_HOTPLUG_FORCE_DETECT;
 248
 249         for (i = 0; i < tries ; i++) {
 250                 /* turn on the FORCE_DETECT */
 251                 I915_WRITE(PORT_HOTPLUG_EN, hotplug_en);
 252                 /* wait for FORCE_DETECT to go off */
 253                 if (wait_for((I915_READ(PORT_HOTPLUG_EN) &
 254                               CRT_HOTPLUG_FORCE_DETECT) == 0,
 255                              1000))
 256                         DRM_DEBUG_KMS("timed out waiting for FORCE_DETECT to go off");
 257         }
 258
 259         stat = I915_READ(PORT_HOTPLUG_STAT);
 260         if ((stat & CRT_HOTPLUG_MONITOR_MASK) != CRT_HOTPLUG_MONITOR_NONE)
 261                 ret = true;
 262
 263         /* clear the interrupt we just generated, if any */
 264         I915_WRITE(PORT_HOTPLUG_STAT, CRT_HOTPLUG_INT_STATUS);
 265
 266         /* and put the bits back */
 267         I915_WRITE(PORT_HOTPLUG_EN, orig);
 268
 269         return ret;
 270 }
 271
 272 static bool intel_crt_detect_ddc(struct drm_connector *connector)
 273 {
 274         struct intel_crt *crt = intel_attached_crt(connector);
 275         struct drm_i915_private *dev_priv = crt->base.base.dev->dev_private;
 276
 277         /* CRT should always be at 0, but check anyway */
 278         if (crt->base.type != INTEL_OUTPUT_ANALOG)
 279                 return false;
 280
 281         if (intel_ddc_probe(&crt->base, dev_priv->crt_ddc_pin)) {
 282                 struct edid *edid;
 283                 bool is_digital = false;
 284
 285                 edid = drm_get_edid(connector,
 286                         &dev_priv->gmbus[dev_priv->crt_ddc_pin].adapter);
 287                 /*
 288                  * This may be a DVI-I connector with a shared DDC
 289                  * link between analog and digital outputs, so we
 290                  * have to check the EDID input spec of the attached device.
 291                  */
 292                 if (edid != NULL) {
 293                         is_digital = edid->input & DRM_EDID_INPUT_DIGITAL;
 294                         connector->display_info.raw_edid = NULL;
 295                         kfree(edid);
 296                 }
 297
 298                 if (!is_digital) {
 299                         DRM_DEBUG_KMS("CRT detected via DDC:0x50 [EDID]\n");
 300                         return true;
 301                 }
 302         }
 303
 304         return false;
 305 }
 306
 307 static enum drm_connector_status
 308 intel_crt_load_detect(struct intel_crt *crt)
 309 {
 310         struct drm_device *dev = crt->base.base.dev;
 311         struct drm_i915_private *dev_priv = dev->dev_private;
 312         uint32_t pipe = to_intel_crtc(crt->base.base.crtc)->pipe;
 313         uint32_t save_bclrpat;
 314         uint32_t save_vtotal;
 315         uint32_t vtotal, vactive;
 316         uint32_t vsample;
 317         uint32_t vblank, vblank_start, vblank_end;
 318         uint32_t dsl;
 319         uint32_t bclrpat_reg;
 320         uint32_t vtotal_reg;
 321         uint32_t vblank_reg;
 322         uint32_t vsync_reg;
 323         uint32_t pipeconf_reg;
 324         uint32_t pipe_dsl_reg;
 325         uint8_t st00;
 326         enum drm_connector_status status;
 327
 328         DRM_DEBUG_KMS("starting load-detect on CRT\n");
 329
 330         bclrpat_reg = BCLRPAT(pipe);
 331         vtotal_reg = VTOTAL(pipe);
 332         vblank_reg = VBLANK(pipe);
 333         vsync_reg = VSYNC(pipe);
 334         pipeconf_reg = PIPECONF(pipe);
 335         pipe_dsl_reg = PIPEDSL(pipe);
 336
 337         save_bclrpat = I915_READ(bclrpat_reg);
 338         save_vtotal = I915_READ(vtotal_reg);
 339         vblank = I915_READ(vblank_reg);
 340
 341         vtotal = ((save_vtotal >> 16) & 0xfff) + 1;
 342         vactive = (save_vtotal & 0x7ff) + 1;
 343
 344         vblank_start = (vblank & 0xfff) + 1;
 345         vblank_end = ((vblank >> 16) & 0xfff) + 1;
 346
 347         /* Set the border color to purple. */
 348         I915_WRITE(bclrpat_reg, 0x500050);
 349
 350         if (!IS_GEN2(dev)) {
 351                 uint32_t pipeconf = I915_READ(pipeconf_reg);
 352                 I915_WRITE(pipeconf_reg, pipeconf | PIPECONF_FORCE_BORDER);
 353                 POSTING_READ(pipeconf_reg);
 354                 /* Wait for next Vblank to substitue
 355                  * border color for Color info */
 356                 intel_wait_for_vblank(dev, pipe);
 357                 st00 = I915_READ8(VGA_MSR_WRITE);
 358                 status = ((st00 & (1 << 4)) != 0) ?
 359                         connector_status_connected :
 360                         connector_status_disconnected;
 361
 362                 I915_WRITE(pipeconf_reg, pipeconf);
 363         } else {
 364                 bool restore_vblank = false;
 365                 int count, detect;
 366
 367                 /*
 368                 * If there isn't any border, add some.
 369                 * Yes, this will flicker
 370                 */
 371                 if (vblank_start <= vactive && vblank_end >= vtotal) {
 372                         uint32_t vsync = I915_READ(vsync_reg);
 373                         uint32_t vsync_start = (vsync & 0xffff) + 1;
 374
 375                         vblank_start = vsync_start;
 376                         I915_WRITE(vblank_reg,
 377                                    (vblank_start - 1) |
 378                                    ((vblank_end - 1) << 16));
 379                         restore_vblank = true;
 380                 }
 381                 /* sample in the vertical border, selecting the larger one */
 382                 if (vblank_start - vactive >= vtotal - vblank_end)
 383                         vsample = (vblank_start + vactive) >> 1;
 384                 else
 385                         vsample = (vtotal + vblank_end) >> 1;
 386
 387                 /*
 388                  * Wait for the border to be displayed
 389                  */
 390                 while (I915_READ(pipe_dsl_reg) >= vactive)
 391                         ;
 392                 while ((dsl = I915_READ(pipe_dsl_reg)) <= vsample)
 393                         ;
 394                 /*
 395                  * Watch ST00 for an entire scanline
 396                  */
 397                 detect = 0;
 398                 count = 0;
 399                 do {
 400                         count++;
 401                         /* Read the ST00 VGA status register */
 402                         st00 = I915_READ8(VGA_MSR_WRITE);
 403                         if (st00 & (1 << 4))
 404                                 detect++;
 405                 } while ((I915_READ(pipe_dsl_reg) == dsl));
 406
 407                 /* restore vblank if necessary */
 408                 if (restore_vblank)
 409                         I915_WRITE(vblank_reg, vblank);
 410                 /*
 411                  * If more than 3/4 of the scanline detected a monitor,
 412                  * then it is assumed to be present. This works even on i830,
 413                  * where there isn't any way to force the border color across
 414                  * the screen
 415                  */
 416                 status = detect * 4 > count * 3 ?
 417                          connector_status_connected :
 418                          connector_status_disconnected;
 419         }
 420
 421         /* Restore previous settings */
 422         I915_WRITE(bclrpat_reg, save_bclrpat);
 423
 424         return status;
 425 }
 426
 427 static enum drm_connector_status
 428 intel_crt_detect(struct drm_connector *connector, bool force)
 429 {
 430         struct drm_device *dev = connector->dev;
 431         struct intel_crt *crt = intel_attached_crt(connector);
 432         struct drm_crtc *crtc;
 433         int dpms_mode;
 434         enum drm_connector_status status;
 435
 436         if (I915_HAS_HOTPLUG(dev)) {
 437                 if (intel_crt_detect_hotplug(connector)) {
 438                         DRM_DEBUG_KMS("CRT detected via hotplug\n");
 439                         return connector_status_connected;
 440                 } else {
 441                         DRM_DEBUG_KMS("CRT not detected via hotplug\n");
 442                         return connector_status_disconnected;
 443                 }
 444         }
 445
 446         if (intel_crt_detect_ddc(connector))
 447                 return connector_status_connected;
 448
 449         if (!force)
 450                 return connector->status;
 451
 452         /* for pre-945g platforms use load detect */
 453         crtc = crt->base.base.crtc;
 454         if (crtc && crtc->enabled) {
 455                 status = intel_crt_load_detect(crt);
 456         } else {
 457                 if (intel_get_load_detect_pipe(&crt->base, connector,
 458                                                NULL, &dpms_mode)) {
 459                         if (intel_crt_detect_ddc(connector))
 460                                 status = connector_status_connected;
 461                         else
 462                                 status = intel_crt_load_detect(crt);
 463                         intel_release_load_detect_pipe(&crt->base,
 464                                                        connector, dpms_mode);
 465                 } else
 466                         status = connector_status_unknown;
 467         }
 468
 469         return status;
 470 }
 471
 472 static void intel_crt_destroy(struct drm_connector *connector)
 473 {
 474         drm_sysfs_connector_remove(connector);
 475         drm_connector_cleanup(connector);
 476         kfree(connector);
 477 }
 478
 479 static int intel_crt_get_modes(struct drm_connector *connector)
 480 {
 481         struct drm_device *dev = connector->dev;
 482         struct drm_i915_private *dev_priv = dev->dev_private;
 483         int ret;
 484
 485         ret = intel_ddc_get_modes(connector,
 486                                  &dev_priv->gmbus[dev_priv->crt_ddc_pin].adapter);
 487         if (ret || !IS_G4X(dev))
 488                 return ret;
 489
 490         /* Try to probe digital port for output in DVI-I -> VGA mode. */
 491         return intel_ddc_get_modes(connector,
 492                                    &dev_priv->gmbus[GMBUS_PORT_DPB].adapter);
 493 }
 494
 495 static int intel_crt_set_property(struct drm_connector *connector,
 496                                   struct drm_property *property,
 497                                   uint64_t value)
 498 {
 499         return 0;
 500 }
 501
 502 static void intel_crt_reset(struct drm_connector *connector)
 503 {
 504         struct drm_device *dev = connector->dev;
 505         struct intel_crt *crt = intel_attached_crt(connector);
 506
 507         if (HAS_PCH_SPLIT(dev))
 508                 crt->force_hotplug_required = 1;
 509 }
 510
 511 /*
 512  * Routines for controlling stuff on the analog port
 513  */
 514
 515 static const struct drm_encoder_helper_funcs intel_crt_helper_funcs = {
 516         .dpms = intel_crt_dpms,
 517         .mode_fixup = intel_crt_mode_fixup,
 518         .prepare = intel_encoder_prepare,
 519         .commit = intel_encoder_commit,
 520         .mode_set = intel_crt_mode_set,
 521 };
 522
 523 static const struct drm_connector_funcs intel_crt_connector_funcs = {
 524         .reset = intel_crt_reset,
 525         .dpms = drm_helper_connector_dpms,
 526         .detect = intel_crt_detect,
 527         .fill_modes = drm_helper_probe_single_connector_modes,
 528         .destroy = intel_crt_destroy,
 529         .set_property = intel_crt_set_property,
 530 };
 531
 532 static const struct drm_connector_helper_funcs intel_crt_connector_helper_funcs = {
 533         .mode_valid = intel_crt_mode_valid,
 534         .get_modes = intel_crt_get_modes,
 535         .best_encoder = intel_best_encoder,
 536 };
 537
 538 static const struct drm_encoder_funcs intel_crt_enc_funcs = {
 539         .destroy = intel_encoder_destroy,
 540 };
 541
 542 void intel_crt_init(struct drm_device *dev)
 543 {
 544         struct drm_connector *connector;
 545         struct intel_crt *crt;
 546         struct intel_connector *intel_connector;
 547         struct drm_i915_private *dev_priv = dev->dev_private;
 548
 549         crt = kzalloc(sizeof(struct intel_crt), GFP_KERNEL);
 550         if (!crt)
 551                 return;
 552
 553         intel_connector = kzalloc(sizeof(struct intel_connector), GFP_KERNEL);
 554         if (!intel_connector) {
 555                 kfree(crt);
 556                 return;
 557         }
 558
 559         connector = &intel_connector->base;
 560         drm_connector_init(dev, &intel_connector->base,
 561                            &intel_crt_connector_funcs, DRM_MODE_CONNECTOR_VGA);
 562
 563         drm_encoder_init(dev, &crt->base.base, &intel_crt_enc_funcs,
 564                          DRM_MODE_ENCODER_DAC);
 565
 566         intel_connector_attach_encoder(intel_connector, &crt->base);
 567
 568         crt->base.type = INTEL_OUTPUT_ANALOG;
 569         crt->base.clone_mask = (1 << INTEL_SDVO_NON_TV_CLONE_BIT |
 570                                 1 << INTEL_ANALOG_CLONE_BIT |
 571                                 1 << INTEL_SDVO_LVDS_CLONE_BIT);
 572         crt->base.crtc_mask = (1 << 0) | (1 << 1);
 573         connector->interlace_allowed = 1;
 574         connector->doublescan_allowed = 0;
 575
 576         drm_encoder_helper_add(&crt->base.base, &intel_crt_helper_funcs);
 577         drm_connector_helper_add(connector, &intel_crt_connector_helper_funcs);
 578
 579         drm_sysfs_connector_add(connector);
 580
 581         if (I915_HAS_HOTPLUG(dev))
 582                 connector->polled = DRM_CONNECTOR_POLL_HPD;
 583         else
 584                 connector->polled = DRM_CONNECTOR_POLL_CONNECT;
 585
 586         /*
 587          * Configure the automatic hotplug detection stuff
 588          */
 589         crt->force_hotplug_required = 0;
 590         if (HAS_PCH_SPLIT(dev)) {
 591                 u32 adpa;
 592
 593                 adpa = I915_READ(PCH_ADPA);
 594                 adpa &= ~ADPA_CRT_HOTPLUG_MASK;
 595                 adpa |= ADPA_HOTPLUG_BITS;
 596                 I915_WRITE(PCH_ADPA, adpa);
 597                 POSTING_READ(PCH_ADPA);
 598
 599                 DRM_DEBUG_KMS("pch crt adpa set to 0x%x\n", adpa);
 600                 crt->force_hotplug_required = 1;
 601         }
 602
 603         dev_priv->hotplug_supported_mask |= CRT_HOTPLUG_INT_STATUS;
 604 }