src/mesa/drivers/dri/r128/r128_screen.c

   1 /* $XFree86: xc/lib/GL/mesa/src/drv/r128/r128_screen.c,v 1.9 2003/03/26 20:43:49 tsi Exp $ */
   2 /**************************************************************************
   3
   4 Copyright 1999, 2000 ATI Technologies Inc. and Precision Insight, Inc.,
   5                                                Cedar Park, Texas.
   6 All Rights Reserved.
   7
   8 Permission is hereby granted, free of charge, to any person obtaining a
   9 copy of this software and associated documentation files (the "Software"),
  10 to deal in the Software without restriction, including without limitation
  11 on the rights to use, copy, modify, merge, publish, distribute, sub
  12 license, and/or sell copies of the Software, and to permit persons to whom
  13 the Software is furnished to do so, subject to the following conditions:
  14
  15 The above copyright notice and this permission notice (including the next
  16 paragraph) shall be included in all copies or substantial portions of the
  17 Software.
  18
  19 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21 FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  22 ATI, PRECISION INSIGHT AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
  23 DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  24 OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  25 USE OR OTHER DEALINGS IN THE SOFTWARE.
  26
  27 **************************************************************************/
  28
  29 /*
  30  * Authors:
  31  *   Gareth Hughes <gareth@valinux.com>
  32  *   Kevin E. Martin <martin@valinux.com>
  33  *
  34  */
  35
  36 #include "r128_dri.h"
  37
  38 #include "r128_context.h"
  39 #include "r128_ioctl.h"
  40 #include "r128_span.h"
  41 #include "r128_tris.h"
  42
  43 #include "context.h"
  44 #include "imports.h"
  45 #include "framebuffer.h"
  46 #include "renderbuffer.h"
  47
  48 #include "utils.h"
  49 #include "vblank.h"
  50
  51 #include "GL/internal/dri_interface.h"
  52
  53 /* R128 configuration
  54  */
  55 #include "xmlpool.h"
  56
  57 PUBLIC const char __driConfigOptions[] =
  58 DRI_CONF_BEGIN
  59     DRI_CONF_SECTION_PERFORMANCE
  60         DRI_CONF_VBLANK_MODE(DRI_CONF_VBLANK_DEF_INTERVAL_0)
  61     DRI_CONF_SECTION_END
  62     DRI_CONF_SECTION_QUALITY
  63         DRI_CONF_TEXTURE_DEPTH(DRI_CONF_TEXTURE_DEPTH_FB)
  64     DRI_CONF_SECTION_END
  65     DRI_CONF_SECTION_DEBUG
  66         DRI_CONF_NO_RAST(false)
  67 #if ENABLE_PERF_BOXES
  68         DRI_CONF_PERFORMANCE_BOXES(false)
  69 #endif
  70     DRI_CONF_SECTION_END
  71 DRI_CONF_END;
  72 #if ENABLE_PERF_BOXES
  73 static const GLuint __driNConfigOptions = 4;
  74 #else
  75 static const GLuint __driNConfigOptions = 3;
  76 #endif
  77
  78 extern const struct dri_extension card_extensions[];
  79
  80 #if 1
  81 /* Including xf86PciInfo.h introduces a bunch of errors...
  82  */
  83 #define PCI_CHIP_RAGE128LE      0x4C45
  84 #define PCI_CHIP_RAGE128LF      0x4C46
  85 #define PCI_CHIP_RAGE128PF      0x5046
  86 #define PCI_CHIP_RAGE128PR      0x5052
  87 #define PCI_CHIP_RAGE128RE      0x5245
  88 #define PCI_CHIP_RAGE128RF      0x5246
  89 #define PCI_CHIP_RAGE128RK      0x524B
  90 #define PCI_CHIP_RAGE128RL      0x524C
  91 #endif
  92
  93
  94 /* Create the device specific screen private data struct.
  95  */
  96 static r128ScreenPtr
  97 r128CreateScreen( __DRIscreenPrivate *sPriv )
  98 {
  99    r128ScreenPtr r128Screen;
 100    R128DRIPtr r128DRIPriv = (R128DRIPtr)sPriv->pDevPriv;
 101    PFNGLXSCRENABLEEXTENSIONPROC glx_enable_extension =
 102      (PFNGLXSCRENABLEEXTENSIONPROC) (*dri_interface->getProcAddress("glxEnableExtension"));
 103    void * const psc = sPriv->psc->screenConfigs;
 104
 105    if (sPriv->devPrivSize != sizeof(R128DRIRec)) {
 106       fprintf(stderr,"\nERROR!  sizeof(R128DRIRec) does not match passed size from device driver\n");
 107       return GL_FALSE;
 108    }
 109
 110    /* Allocate the private area */
 111    r128Screen = (r128ScreenPtr) CALLOC( sizeof(*r128Screen) );
 112    if ( !r128Screen ) return NULL;
 113
 114    /* parse information in __driConfigOptions */
 115    driParseOptionInfo (&r128Screen->optionCache,
 116                        __driConfigOptions, __driNConfigOptions);
 117
 118    /* This is first since which regions we map depends on whether or
 119     * not we are using a PCI card.
 120     */
 121    r128Screen->IsPCI = r128DRIPriv->IsPCI;
 122    r128Screen->sarea_priv_offset = r128DRIPriv->sarea_priv_offset;
 123
 124    if (sPriv->drmMinor >= 3) {
 125       drm_r128_getparam_t gp;
 126       int ret;
 127
 128       gp.param = R128_PARAM_IRQ_NR;
 129       gp.value = &r128Screen->irq;
 130
 131       ret = drmCommandWriteRead( sPriv->fd, DRM_R128_GETPARAM,
 132                                     &gp, sizeof(gp));
 133       if (ret) {
 134          fprintf(stderr, "drmR128GetParam (R128_PARAM_IRQ_NR): %d\n", ret);
 135          FREE( r128Screen );
 136          return NULL;
 137       }
 138    }
 139
 140    r128Screen->mmio.handle = r128DRIPriv->registerHandle;
 141    r128Screen->mmio.size   = r128DRIPriv->registerSize;
 142    if ( drmMap( sPriv->fd,
 143                 r128Screen->mmio.handle,
 144                 r128Screen->mmio.size,
 145                 (drmAddressPtr)&r128Screen->mmio.map ) ) {
 146       FREE( r128Screen );
 147       return NULL;
 148    }
 149
 150    r128Screen->buffers = drmMapBufs( sPriv->fd );
 151    if ( !r128Screen->buffers ) {
 152       drmUnmap( (drmAddress)r128Screen->mmio.map, r128Screen->mmio.size );
 153       FREE( r128Screen );
 154       return NULL;
 155    }
 156
 157    if ( !r128Screen->IsPCI ) {
 158       r128Screen->agpTextures.handle = r128DRIPriv->agpTexHandle;
 159       r128Screen->agpTextures.size   = r128DRIPriv->agpTexMapSize;
 160       if ( drmMap( sPriv->fd,
 161                    r128Screen->agpTextures.handle,
 162                    r128Screen->agpTextures.size,
 163                    (drmAddressPtr)&r128Screen->agpTextures.map ) ) {
 164          drmUnmapBufs( r128Screen->buffers );
 165          drmUnmap( (drmAddress)r128Screen->mmio.map, r128Screen->mmio.size );
 166          FREE( r128Screen );
 167          return NULL;
 168       }
 169    }
 170
 171    switch ( r128DRIPriv->deviceID ) {
 172    case PCI_CHIP_RAGE128RE:
 173    case PCI_CHIP_RAGE128RF:
 174    case PCI_CHIP_RAGE128RK:
 175    case PCI_CHIP_RAGE128RL:
 176       r128Screen->chipset = R128_CARD_TYPE_R128;
 177       break;
 178    case PCI_CHIP_RAGE128PF:
 179       r128Screen->chipset = R128_CARD_TYPE_R128_PRO;
 180       break;
 181    case PCI_CHIP_RAGE128LE:
 182    case PCI_CHIP_RAGE128LF:
 183       r128Screen->chipset = R128_CARD_TYPE_R128_MOBILITY;
 184       break;
 185    default:
 186       r128Screen->chipset = R128_CARD_TYPE_R128;
 187       break;
 188    }
 189
 190    r128Screen->cpp = r128DRIPriv->bpp / 8;
 191    r128Screen->AGPMode = r128DRIPriv->AGPMode;
 192
 193    r128Screen->frontOffset      = r128DRIPriv->frontOffset;
 194    r128Screen->frontPitch       = r128DRIPriv->frontPitch;
 195    r128Screen->backOffset       = r128DRIPriv->backOffset;
 196    r128Screen->backPitch        = r128DRIPriv->backPitch;
 197    r128Screen->depthOffset      = r128DRIPriv->depthOffset;
 198    r128Screen->depthPitch       = r128DRIPriv->depthPitch;
 199    r128Screen->spanOffset       = r128DRIPriv->spanOffset;
 200
 201    if ( r128DRIPriv->textureSize == 0 ) {
 202       r128Screen->texOffset[R128_LOCAL_TEX_HEAP] =
 203          r128DRIPriv->agpTexOffset + R128_AGP_TEX_OFFSET;
 204       r128Screen->texSize[R128_LOCAL_TEX_HEAP] = r128DRIPriv->agpTexMapSize;
 205       r128Screen->logTexGranularity[R128_LOCAL_TEX_HEAP] =
 206          r128DRIPriv->log2AGPTexGran;
 207    } else {
 208       r128Screen->texOffset[R128_LOCAL_TEX_HEAP] = r128DRIPriv->textureOffset;
 209       r128Screen->texSize[R128_LOCAL_TEX_HEAP] = r128DRIPriv->textureSize;
 210       r128Screen->logTexGranularity[R128_LOCAL_TEX_HEAP] = r128DRIPriv->log2TexGran;
 211    }
 212
 213    if ( !r128Screen->agpTextures.map || r128DRIPriv->textureSize == 0 ) {
 214       r128Screen->numTexHeaps = R128_NR_TEX_HEAPS - 1;
 215       r128Screen->texOffset[R128_AGP_TEX_HEAP] = 0;
 216       r128Screen->texSize[R128_AGP_TEX_HEAP] = 0;
 217       r128Screen->logTexGranularity[R128_AGP_TEX_HEAP] = 0;
 218    } else {
 219       r128Screen->numTexHeaps = R128_NR_TEX_HEAPS;
 220       r128Screen->texOffset[R128_AGP_TEX_HEAP] =
 221          r128DRIPriv->agpTexOffset + R128_AGP_TEX_OFFSET;
 222       r128Screen->texSize[R128_AGP_TEX_HEAP] = r128DRIPriv->agpTexMapSize;
 223       r128Screen->logTexGranularity[R128_AGP_TEX_HEAP] =
 224          r128DRIPriv->log2AGPTexGran;
 225    }
 226
 227    r128Screen->driScreen = sPriv;
 228
 229    if ( glx_enable_extension != NULL ) {
 230       if ( r128Screen->irq != 0 ) {
 231          (*glx_enable_extension)( psc, "GLX_SGI_swap_control" );
 232          (*glx_enable_extension)( psc, "GLX_SGI_video_sync" );
 233          (*glx_enable_extension)( psc, "GLX_MESA_swap_control" );
 234       }
 235
 236       (*glx_enable_extension)( psc, "GLX_MESA_swap_frame_usage" );
 237    }
 238
 239    return r128Screen;
 240 }
 241
 242 /* Destroy the device specific screen private data struct.
 243  */
 244 static void
 245 r128DestroyScreen( __DRIscreenPrivate *sPriv )
 246 {
 247    r128ScreenPtr r128Screen = (r128ScreenPtr)sPriv->private;
 248
 249    if ( !r128Screen )
 250       return;
 251
 252    if ( !r128Screen->IsPCI ) {
 253       drmUnmap( (drmAddress)r128Screen->agpTextures.map,
 254                 r128Screen->agpTextures.size );
 255    }
 256    drmUnmapBufs( r128Screen->buffers );
 257    drmUnmap( (drmAddress)r128Screen->mmio.map, r128Screen->mmio.size );
 258
 259    /* free all option information */
 260    driDestroyOptionInfo (&r128Screen->optionCache);
 261
 262    FREE( r128Screen );
 263    sPriv->private = NULL;
 264 }
 265
 266
 267 /* Create and initialize the Mesa and driver specific pixmap buffer
 268  * data.
 269  */
 270 static GLboolean
 271 r128CreateBuffer( __DRIscreenPrivate *driScrnPriv,
 272                   __DRIdrawablePrivate *driDrawPriv,
 273                   const __GLcontextModes *mesaVis,
 274                   GLboolean isPixmap )
 275 {
 276    r128ScreenPtr screen = (r128ScreenPtr) driScrnPriv->private;
 277
 278    if (isPixmap) {
 279       return GL_FALSE; /* not implemented */
 280    }
 281    else {
 282       const GLboolean swDepth = GL_FALSE;
 283       const GLboolean swAlpha = GL_FALSE;
 284       const GLboolean swAccum = mesaVis->accumRedBits > 0;
 285       const GLboolean swStencil = mesaVis->stencilBits > 0 &&
 286          mesaVis->depthBits != 24;
 287       struct gl_framebuffer *fb = _mesa_create_framebuffer(mesaVis);
 288
 289       {
 290          driRenderbuffer *frontRb
 291             = driNewRenderbuffer(GL_RGBA,
 292                                  NULL,
 293                                  screen->cpp,
 294                                  screen->frontOffset, screen->frontPitch,
 295                                  driDrawPriv);
 296          r128SetSpanFunctions(frontRb, mesaVis);
 297          _mesa_add_renderbuffer(fb, BUFFER_FRONT_LEFT, &frontRb->Base);
 298       }
 299
 300       if (mesaVis->doubleBufferMode) {
 301          driRenderbuffer *backRb
 302             = driNewRenderbuffer(GL_RGBA,
 303                                  NULL,
 304                                  screen->cpp,
 305                                  screen->backOffset, screen->backPitch,
 306                                  driDrawPriv);
 307          r128SetSpanFunctions(backRb, mesaVis);
 308          _mesa_add_renderbuffer(fb, BUFFER_BACK_LEFT, &backRb->Base);
 309       }
 310
 311       if (mesaVis->depthBits == 16) {
 312          driRenderbuffer *depthRb
 313             = driNewRenderbuffer(GL_DEPTH_COMPONENT16,
 314                                  NULL,
 315                                  screen->cpp,
 316                                  screen->depthOffset, screen->depthPitch,
 317                                  driDrawPriv);
 318          r128SetSpanFunctions(depthRb, mesaVis);
 319          _mesa_add_renderbuffer(fb, BUFFER_DEPTH, &depthRb->Base);
 320       }
 321       else if (mesaVis->depthBits == 24) {
 322          driRenderbuffer *depthRb
 323             = driNewRenderbuffer(GL_DEPTH_COMPONENT24,
 324                                  NULL,
 325                                  screen->cpp,
 326                                  screen->depthOffset, screen->depthPitch,
 327                                  driDrawPriv);
 328          r128SetSpanFunctions(depthRb, mesaVis);
 329          _mesa_add_renderbuffer(fb, BUFFER_DEPTH, &depthRb->Base);
 330       }
 331
 332       if (mesaVis->stencilBits > 0 && !swStencil) {
 333          driRenderbuffer *stencilRb
 334             = driNewRenderbuffer(GL_STENCIL_INDEX8_EXT,
 335                                  NULL,
 336                                  screen->cpp,
 337                                  screen->depthOffset, screen->depthPitch,
 338                                  driDrawPriv);
 339          r128SetSpanFunctions(stencilRb, mesaVis);
 340          _mesa_add_renderbuffer(fb, BUFFER_STENCIL, &stencilRb->Base);
 341       }
 342
 343       _mesa_add_soft_renderbuffers(fb,
 344                                    GL_FALSE, /* color */
 345                                    swDepth,
 346                                    swStencil,
 347                                    swAccum,
 348                                    swAlpha,
 349                                    GL_FALSE /* aux */);
 350       driDrawPriv->driverPrivate = (void *) fb;
 351
 352       return (driDrawPriv->driverPrivate != NULL);
 353    }
 354 }
 355
 356
 357 static void
 358 r128DestroyBuffer(__DRIdrawablePrivate *driDrawPriv)
 359 {
 360    _mesa_destroy_framebuffer((GLframebuffer *) (driDrawPriv->driverPrivate));
 361 }
 362
 363
 364 /* Copy the back color buffer to the front color buffer */
 365 static void
 366 r128SwapBuffers(__DRIdrawablePrivate *dPriv)
 367 {
 368    if (dPriv->driContextPriv && dPriv->driContextPriv->driverPrivate) {
 369       r128ContextPtr rmesa;
 370       GLcontext *ctx;
 371       rmesa = (r128ContextPtr) dPriv->driContextPriv->driverPrivate;
 372       ctx = rmesa->glCtx;
 373       if (ctx->Visual.doubleBufferMode) {
 374          _mesa_notifySwapBuffers( ctx );  /* flush pending rendering comands */
 375          if ( rmesa->doPageFlip ) {
 376             r128PageFlip( dPriv );
 377          }
 378          else {
 379             r128CopyBuffer( dPriv );
 380          }
 381       }
 382    }
 383    else {
 384       /* XXX this shouldn't be an error but we can't handle it for now */
 385       _mesa_problem(NULL, "%s: drawable has no context!", __FUNCTION__);
 386    }
 387 }
 388
 389
 390 /* Initialize the driver specific screen private data.
 391  */
 392 static GLboolean
 393 r128InitDriver( __DRIscreenPrivate *sPriv )
 394 {
 395    sPriv->private = (void *) r128CreateScreen( sPriv );
 396
 397    if ( !sPriv->private ) {
 398       r128DestroyScreen( sPriv );
 399       return GL_FALSE;
 400    }
 401
 402    return GL_TRUE;
 403 }
 404
 405
 406 static struct __DriverAPIRec r128API = {
 407    .InitDriver      = r128InitDriver,
 408    .DestroyScreen   = r128DestroyScreen,
 409    .CreateContext   = r128CreateContext,
 410    .DestroyContext  = r128DestroyContext,
 411    .CreateBuffer    = r128CreateBuffer,
 412    .DestroyBuffer   = r128DestroyBuffer,
 413    .SwapBuffers     = r128SwapBuffers,
 414    .MakeCurrent     = r128MakeCurrent,
 415    .UnbindContext   = r128UnbindContext,
 416    .GetSwapInfo     = NULL,
 417    .GetMSC          = driGetMSC32,
 418    .WaitForMSC      = driWaitForMSC32,
 419    .WaitForSBC      = NULL,
 420    .SwapBuffersMSC  = NULL
 421
 422 };
 423
 424
 425 static __GLcontextModes *
 426 r128FillInModes( unsigned pixel_bits, unsigned depth_bits,
 427                  unsigned stencil_bits, GLboolean have_back_buffer )
 428 {
 429     __GLcontextModes * modes;
 430     __GLcontextModes * m;
 431     unsigned num_modes;
 432     unsigned depth_buffer_factor;
 433     unsigned back_buffer_factor;
 434     GLenum fb_format;
 435     GLenum fb_type;
 436
 437     /* Right now GLX_SWAP_COPY_OML isn't supported, but it would be easy
 438      * enough to add support.  Basically, if a context is created with an
 439      * fbconfig where the swap method is GLX_SWAP_COPY_OML, pageflipping
 440      * will never be used.
 441      */
 442     static const GLenum back_buffer_modes[] = {
 443         GLX_NONE, GLX_SWAP_UNDEFINED_OML /*, GLX_SWAP_COPY_OML */
 444     };
 445
 446     u_int8_t depth_bits_array[2];
 447     u_int8_t stencil_bits_array[2];
 448
 449
 450     depth_bits_array[0] = depth_bits;
 451     depth_bits_array[1] = depth_bits;
 452
 453     /* Just like with the accumulation buffer, always provide some modes
 454      * with a stencil buffer.  It will be a sw fallback, but some apps won't
 455      * care about that.
 456      */
 457     stencil_bits_array[0] = 0;
 458     stencil_bits_array[1] = (stencil_bits == 0) ? 8 : stencil_bits;
 459
 460     depth_buffer_factor = ((depth_bits != 0) || (stencil_bits != 0)) ? 2 : 1;
 461     back_buffer_factor  = (have_back_buffer) ? 2 : 1;
 462
 463     num_modes = depth_buffer_factor * back_buffer_factor * 4;
 464
 465     if ( pixel_bits == 16 ) {
 466         fb_format = GL_RGB;
 467         fb_type = GL_UNSIGNED_SHORT_5_6_5;
 468     }
 469     else {
 470         fb_format = GL_BGR;
 471         fb_type = GL_UNSIGNED_INT_8_8_8_8_REV;
 472     }
 473
 474     modes = (*dri_interface->createContextModes)( num_modes, sizeof( __GLcontextModes ) );
 475     m = modes;
 476     if ( ! driFillInModes( & m, fb_format, fb_type,
 477                            depth_bits_array, stencil_bits_array, depth_buffer_factor,
 478                            back_buffer_modes, back_buffer_factor,
 479                            GLX_TRUE_COLOR ) ) {
 480         fprintf( stderr, "[%s:%u] Error creating FBConfig!\n",
 481                  __func__, __LINE__ );
 482         return NULL;
 483     }
 484
 485     if ( ! driFillInModes( & m, fb_format, fb_type,
 486                            depth_bits_array, stencil_bits_array, depth_buffer_factor,
 487                            back_buffer_modes, back_buffer_factor,
 488                            GLX_DIRECT_COLOR ) ) {
 489         fprintf( stderr, "[%s:%u] Error creating FBConfig!\n",
 490                  __func__, __LINE__ );
 491         return NULL;
 492     }
 493
 494     /* Mark the visual as slow if there are "fake" stencil bits.
 495      */
 496     for ( m = modes ; m != NULL ; m = m->next ) {
 497         if ( (m->stencilBits != 0) && (m->stencilBits != stencil_bits) ) {
 498             m->visualRating = GLX_SLOW_CONFIG;
 499         }
 500     }
 501
 502     return modes;
 503 }
 504
 505
 506 /**
 507  * This is the bootstrap function for the driver.  libGL supplies all of the
 508  * requisite information about the system, and the driver initializes itself.
 509  * This routine also fills in the linked list pointed to by \c driver_modes
 510  * with the \c __GLcontextModes that the driver can support for windows or
 511  * pbuffers.
 512  *
 513  * \return A pointer to a \c __DRIscreenPrivate on success, or \c NULL on
 514  *         failure.
 515  */
 516 PUBLIC
 517 void * __driCreateNewScreen_20050727( __DRInativeDisplay *dpy, int scrn, __DRIscreen *psc,
 518                              const __GLcontextModes * modes,
 519                              const __DRIversion * ddx_version,
 520                              const __DRIversion * dri_version,
 521                              const __DRIversion * drm_version,
 522                              const __DRIframebuffer * frame_buffer,
 523                              drmAddress pSAREA, int fd,
 524                              int internal_api_version,
 525                              const __DRIinterfaceMethods * interface,
 526                              __GLcontextModes ** driver_modes )
 527
 528 {
 529    __DRIscreenPrivate *psp;
 530    static const __DRIversion ddx_expected = { 4, 0, 0 };
 531    static const __DRIversion dri_expected = { 4, 0, 0 };
 532    static const __DRIversion drm_expected = { 2, 2, 0 };
 533
 534
 535    dri_interface = interface;
 536
 537    if ( ! driCheckDriDdxDrmVersions2( "Rage128",
 538                                       dri_version, & dri_expected,
 539                                       ddx_version, & ddx_expected,
 540                                       drm_version, & drm_expected ) ) {
 541       return NULL;
 542    }
 543
 544    psp = __driUtilCreateNewScreen(dpy, scrn, psc, NULL,
 545                                   ddx_version, dri_version, drm_version,
 546                                   frame_buffer, pSAREA, fd,
 547                                   internal_api_version, &r128API);
 548    if ( psp != NULL ) {
 549       R128DRIPtr dri_priv = (R128DRIPtr) psp->pDevPriv;
 550       *driver_modes = r128FillInModes( dri_priv->bpp,
 551                                        (dri_priv->bpp == 16) ? 16 : 24,
 552                                        (dri_priv->bpp == 16) ? 0  : 8,
 553                                        (dri_priv->backOffset != dri_priv->depthOffset) );
 554
 555       /* Calling driInitExtensions here, with a NULL context pointer, does not actually
 556        * enable the extensions.  It just makes sure that all the dispatch offsets for all
 557        * the extensions that *might* be enables are known.  This is needed because the
 558        * dispatch offsets need to be known when _mesa_context_create is called, but we can't
 559        * enable the extensions until we have a context pointer.
 560        *
 561        * Hello chicken.  Hello egg.  How are you two today?
 562        */
 563       driInitExtensions( NULL, card_extensions, GL_FALSE );
 564    }
 565
 566    return (void *) psp;
 567 }