path: root/src/mesa/drivers/dri/i965/intel_screen.c

/**************************************************************************
 * 
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * All Rights Reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * 
 **************************************************************************/

#include "glheader.h"
#include "context.h"
#include "framebuffer.h"
#include "matrix.h"
#include "renderbuffer.h"
#include "simple_list.h"
#include "utils.h"
#include "vblank.h"
#include "xmlpool.h"


#include "intel_screen.h"

#include "intel_context.h"
#include "intel_tex.h"
#include "intel_span.h"
#include "intel_ioctl.h"
#include "intel_regions.h"
#include "intel_bufmgr_ttm.h"

#include "i915_drm.h"
#include "i830_dri.h"

PUBLIC const char __driConfigOptions[] =
DRI_CONF_BEGIN
    DRI_CONF_SECTION_PERFORMANCE
       DRI_CONF_FTHROTTLE_MODE(DRI_CONF_FTHROTTLE_IRQS) 
       DRI_CONF_VBLANK_MODE(DRI_CONF_VBLANK_DEF_INTERVAL_0)
    DRI_CONF_SECTION_END
    DRI_CONF_SECTION_QUALITY
       DRI_CONF_FORCE_S3TC_ENABLE(false)
       DRI_CONF_ALLOW_LARGE_TEXTURES(1)
      DRI_CONF_SECTION_END
DRI_CONF_END;
const GLuint __driNConfigOptions = 4;

#ifdef USE_NEW_INTERFACE
static PFNGLXCREATECONTEXTMODES create_context_modes = NULL;
#endif /*USE_NEW_INTERFACE*/

/**
 * Map all the memory regions described by the screen.
 * \return GL_TRUE if success, GL_FALSE if error.
 */
GLboolean
intelMapScreenRegions(__DRIscreenPrivate *sPriv)
{
   intelScreenPrivate *intelScreen = (intelScreenPrivate *)sPriv->private;

   if (intelScreen->front.handle) {
      if (drmMap(sPriv->fd,
                 intelScreen->front.handle,
                 intelScreen->front.size,
                 (drmAddress *)&intelScreen->front.map) != 0) {
         _mesa_problem(NULL, "drmMap(frontbuffer) failed!");
         return GL_FALSE;
      }
   } else {
      /* Use the old static allocation method if the server isn't setting up
       * a movable handle for us.  Add in the front buffer offset from
       * framebuffer start, as our span routines (unlike other drivers) expect
       * the renderbuffer address to point to the beginning of the
       * renderbuffer.
       */
      intelScreen->front.map = (char *)sPriv->pFB;
      if (intelScreen->front.map == NULL) {
	 fprintf(stderr, "Failed to find framebuffer mapping\n");
	 return GL_FALSE;
      }
   }

   if (drmMap(sPriv->fd,
              intelScreen->back.handle,
              intelScreen->back.size,
              (drmAddress *)&intelScreen->back.map) != 0) {
      intelUnmapScreenRegions(intelScreen);
      return GL_FALSE;
   }

   if (drmMap(sPriv->fd,
              intelScreen->depth.handle,
              intelScreen->depth.size,
              (drmAddress *)&intelScreen->depth.map) != 0) {
      intelUnmapScreenRegions(intelScreen);
      return GL_FALSE;
   }

   if (drmMap(sPriv->fd,
              intelScreen->tex.handle,
              intelScreen->tex.size,
              (drmAddress *)&intelScreen->tex.map) != 0) {
      intelUnmapScreenRegions(intelScreen);
      return GL_FALSE;
   }

   if (0)
      printf("Mappings:  front: %p  back: %p  depth: %p  tex: %p\n",
          intelScreen->front.map,
          intelScreen->back.map,
          intelScreen->depth.map,
          intelScreen->tex.map);
   return GL_TRUE;
}

void
intelUnmapScreenRegions(intelScreenPrivate *intelScreen)
{
#define REALLY_UNMAP 1
   /* If front.handle is present, we're doing the dynamic front buffer mapping,
    * but if we've fallen back to static allocation then we shouldn't try to
    * unmap here.
    */
   if (intelScreen->front.handle) {
#if REALLY_UNMAP
      if (drmUnmap(intelScreen->front.map, intelScreen->front.size) != 0)
         printf("drmUnmap front failed!\n");
#endif
      intelScreen->front.map = NULL;
   }
   if (intelScreen->back.map) {
#if REALLY_UNMAP
      if (drmUnmap(intelScreen->back.map, intelScreen->back.size) != 0)
         printf("drmUnmap back failed!\n");
#endif
      intelScreen->back.map = NULL;
   }
   if (intelScreen->depth.map) {
#if REALLY_UNMAP
      drmUnmap(intelScreen->depth.map, intelScreen->depth.size);
      intelScreen->depth.map = NULL;
#endif
   }
   if (intelScreen->tex.map) {
#if REALLY_UNMAP
      drmUnmap(intelScreen->tex.map, intelScreen->tex.size);
      intelScreen->tex.map = NULL;
#endif
   }
}


static void
intelPrintDRIInfo(intelScreenPrivate *intelScreen,
                  __DRIscreenPrivate *sPriv,
                  I830DRIPtr gDRIPriv)
{
   fprintf(stderr, "*** Front size:   0x%x  offset: 0x%x  pitch: %d\n",
           intelScreen->front.size, intelScreen->front.offset,
           intelScreen->front.pitch);
   fprintf(stderr, "*** Back size:    0x%x  offset: 0x%x  pitch: %d\n",
           intelScreen->back.size, intelScreen->back.offset,
           intelScreen->back.pitch);
   fprintf(stderr, "*** Depth size:   0x%x  offset: 0x%x  pitch: %d\n",
           intelScreen->depth.size, intelScreen->depth.offset,
           intelScreen->depth.pitch);
   fprintf(stderr, "*** Rotated size: 0x%x  offset: 0x%x  pitch: %d\n",
           intelScreen->rotated.size, intelScreen->rotated.offset,
           intelScreen->rotated.pitch);
   fprintf(stderr, "*** Texture size: 0x%x  offset: 0x%x\n",
           intelScreen->tex.size, intelScreen->tex.offset);
   fprintf(stderr, "*** Memory : 0x%x\n", gDRIPriv->mem);
}


static void
intelPrintSAREA(volatile drmI830Sarea *sarea)
{
   fprintf(stderr, "SAREA: sarea width %d  height %d\n", sarea->width, sarea->height);
   fprintf(stderr, "SAREA: pitch: %d\n", sarea->pitch);
   fprintf(stderr,
           "SAREA: front offset: 0x%08x  size: 0x%x  handle: 0x%x\n",
           sarea->front_offset, sarea->front_size,
           (unsigned) sarea->front_handle);
   fprintf(stderr,
           "SAREA: back  offset: 0x%08x  size: 0x%x  handle: 0x%x\n",
           sarea->back_offset, sarea->back_size,
           (unsigned) sarea->back_handle);
   fprintf(stderr, "SAREA: depth offset: 0x%08x  size: 0x%x  handle: 0x%x\n",
           sarea->depth_offset, sarea->depth_size,
           (unsigned) sarea->depth_handle);
   fprintf(stderr, "SAREA: tex   offset: 0x%08x  size: 0x%x  handle: 0x%x\n",
           sarea->tex_offset, sarea->tex_size,
           (unsigned) sarea->tex_handle);
   fprintf(stderr, "SAREA: rotation: %d\n", sarea->rotation);
   fprintf(stderr,
           "SAREA: rotated offset: 0x%08x  size: 0x%x\n",
           sarea->rotated_offset, sarea->rotated_size);
   fprintf(stderr, "SAREA: rotated pitch: %d\n", sarea->rotated_pitch);
}


/**
 * A number of the screen parameters are obtained/computed from
 * information in the SAREA.  This function updates those parameters.
 */
void
intelUpdateScreenFromSAREA(intelScreenPrivate *intelScreen,
                           volatile drmI830Sarea *sarea)
{
   intelScreen->width = sarea->width;
   intelScreen->height = sarea->height;

   intelScreen->front.offset = sarea->front_offset;
   intelScreen->front.pitch = sarea->pitch * intelScreen->cpp;
   intelScreen->front.handle = sarea->front_handle;
   intelScreen->front.size = sarea->front_size;
   intelScreen->front.tiled = sarea->front_tiled;

   intelScreen->back.offset = sarea->back_offset;
   intelScreen->back.pitch = sarea->pitch * intelScreen->cpp;
   intelScreen->back.handle = sarea->back_handle;
   intelScreen->back.size = sarea->back_size;
   intelScreen->back.tiled = sarea->back_tiled;

   intelScreen->depth.offset = sarea->depth_offset;
   intelScreen->depth.pitch = sarea->pitch * intelScreen->cpp;
   intelScreen->depth.handle = sarea->depth_handle;
   intelScreen->depth.size = sarea->depth_size;
   intelScreen->depth.tiled = sarea->depth_tiled;

   if (intelScreen->driScrnPriv->ddx_version.minor >= 9) {
      intelScreen->front.bo_handle = sarea->front_bo_handle;
      intelScreen->back.bo_handle = sarea->back_bo_handle;
      intelScreen->depth.bo_handle = sarea->depth_bo_handle;
   } else {
      intelScreen->front.bo_handle = -1;
      intelScreen->back.bo_handle = -1;
      intelScreen->depth.bo_handle = -1;
   }

   intelScreen->tex.offset = sarea->tex_offset;
   intelScreen->logTextureGranularity = sarea->log_tex_granularity;
   intelScreen->tex.handle = sarea->tex_handle;
   intelScreen->tex.size = sarea->tex_size;

   intelScreen->rotated.offset = sarea->rotated_offset;
   intelScreen->rotated.pitch = sarea->rotated_pitch * intelScreen->cpp;
   intelScreen->rotated.size = sarea->rotated_size;
   intelScreen->rotated.tiled = sarea->rotated_tiled;
   intelScreen->current_rotation = sarea->rotation;
#if 0
   matrix23Rotate(&intelScreen->rotMatrix,
                  sarea->width, sarea->height, sarea->rotation);
#endif
   intelScreen->rotatedWidth = sarea->virtualX;
   intelScreen->rotatedHeight = sarea->virtualY;

   if (0)
      intelPrintSAREA(sarea);
}

static const __DRIextension *intelExtensions[] = {
    &driReadDrawableExtension,
    &driCopySubBufferExtension.base,
    &driSwapControlExtension.base,
    &driFrameTrackingExtension.base,
    &driMediaStreamCounterExtension.base,
    NULL
};

static GLboolean intelInitDriver(__DRIscreenPrivate *sPriv)
{
   intelScreenPrivate *intelScreen;
   I830DRIPtr         gDRIPriv = (I830DRIPtr)sPriv->pDevPriv;
   volatile drmI830Sarea *sarea;

   if (sPriv->devPrivSize != sizeof(I830DRIRec)) {
      fprintf(stderr,"\nERROR!  sizeof(I830DRIRec) (%ld) does not match passed size from device driver (%d)\n", (unsigned long)sizeof(I830DRIRec), sPriv->devPrivSize);
      return GL_FALSE;
   }

   /* Allocate the private area */
   intelScreen = (intelScreenPrivate *)CALLOC(sizeof(intelScreenPrivate));
   if (!intelScreen) {
      fprintf(stderr,"\nERROR!  Allocating private area failed\n");
      return GL_FALSE;
   }
   /* parse information in __driConfigOptions */
   driParseOptionInfo (&intelScreen->optionCache,
		       __driConfigOptions, __driNConfigOptions);

   intelScreen->driScrnPriv = sPriv;
   sPriv->private = (void *)intelScreen;
   intelScreen->sarea_priv_offset = gDRIPriv->sarea_priv_offset;
   sarea = (volatile drmI830Sarea *)
         (((GLubyte *)sPriv->pSAREA)+intelScreen->sarea_priv_offset);

   intelScreen->deviceID = gDRIPriv->deviceID;
   intelScreen->mem = gDRIPriv->mem;
   intelScreen->cpp = gDRIPriv->cpp;

   switch (gDRIPriv->bitsPerPixel) {
   case 15: intelScreen->fbFormat = DV_PF_555; break;
   case 16: intelScreen->fbFormat = DV_PF_565; break;
   case 32: intelScreen->fbFormat = DV_PF_8888; break;
   }
			 
   intelUpdateScreenFromSAREA(intelScreen, sarea);

   if (0)
      intelPrintDRIInfo(intelScreen, sPriv, gDRIPriv);

   if (!intelMapScreenRegions(sPriv)) {
      fprintf(stderr,"\nERROR!  mapping regions\n");
      _mesa_free(intelScreen);
      sPriv->private = NULL;
      return GL_FALSE;
   }

   intelScreen->drmMinor = sPriv->drm_version.minor;

   /* Determine if IRQs are active? */
   {
      int ret;
      drmI830GetParam gp;

      gp.param = I830_PARAM_IRQ_ACTIVE;
      gp.value = &intelScreen->irq_active;

      ret = drmCommandWriteRead( sPriv->fd, DRM_I830_GETPARAM,
				 &gp, sizeof(gp));
      if (ret) {
	 fprintf(stderr, "drmI830GetParam: %d\n", ret);
	 return GL_FALSE;
      }
   }

   /* Determine if batchbuffers are allowed */
   {
      int ret;
      drmI830GetParam gp;

      gp.param = I830_PARAM_ALLOW_BATCHBUFFER;
      gp.value = &intelScreen->allow_batchbuffer;

      ret = drmCommandWriteRead( sPriv->fd, DRM_I830_GETPARAM,
				 &gp, sizeof(gp));
      if (ret) {
	 fprintf(stderr, "drmI830GetParam: (%d) %d\n", gp.param, ret);
	 return GL_FALSE;
      }
   }

   sPriv->extensions = intelExtensions;

   return GL_TRUE;
}


static void intelDestroyScreen(__DRIscreenPrivate *sPriv)
{
   intelScreenPrivate *intelScreen = (intelScreenPrivate *)sPriv->private;

   intelUnmapScreenRegions(intelScreen);
   FREE(intelScreen);
   sPriv->private = NULL;
}

static GLboolean intelCreateBuffer( __DRIscreenPrivate *driScrnPriv,
				    __DRIdrawablePrivate *driDrawPriv,
				    const __GLcontextModes *mesaVis,
				    GLboolean isPixmap )
{
   intelScreenPrivate *screen = (intelScreenPrivate *) driScrnPriv->private;

   if (isPixmap) {
      return GL_FALSE; /* not implemented */
   } else {
      GLboolean swStencil = (mesaVis->stencilBits > 0 && 
			     mesaVis->depthBits != 24);

      struct gl_framebuffer *fb = _mesa_create_framebuffer(mesaVis);

      {
         driRenderbuffer *frontRb
            = driNewRenderbuffer(GL_RGBA,
                                 screen->front.map,
                                 screen->cpp,
                                 screen->front.offset, screen->front.pitch,
                                 driDrawPriv);
         intelSetSpanFunctions(frontRb, mesaVis);
         _mesa_add_renderbuffer(fb, BUFFER_FRONT_LEFT, &frontRb->Base);
      }

      if (mesaVis->doubleBufferMode) {
         driRenderbuffer *backRb
            = driNewRenderbuffer(GL_RGBA,
                                 screen->back.map,
                                 screen->cpp,
                                 screen->back.offset, screen->back.pitch,
                                 driDrawPriv);
         intelSetSpanFunctions(backRb, mesaVis);
         _mesa_add_renderbuffer(fb, BUFFER_BACK_LEFT, &backRb->Base);
      }

      if (mesaVis->depthBits == 16) {
         driRenderbuffer *depthRb
            = driNewRenderbuffer(GL_DEPTH_COMPONENT16,
                                 screen->depth.map,
                                 screen->cpp,
                                 screen->depth.offset, screen->depth.pitch,
                                 driDrawPriv);
         intelSetSpanFunctions(depthRb, mesaVis);
         _mesa_add_renderbuffer(fb, BUFFER_DEPTH, &depthRb->Base);
      }
      else if (mesaVis->depthBits == 24) {
         driRenderbuffer *depthRb
            = driNewRenderbuffer(GL_DEPTH_COMPONENT24,
                                 screen->depth.map,
                                 screen->cpp,
                                 screen->depth.offset, screen->depth.pitch,
                                 driDrawPriv);
         intelSetSpanFunctions(depthRb, mesaVis);
         _mesa_add_renderbuffer(fb, BUFFER_DEPTH, &depthRb->Base);
      }

      if (mesaVis->stencilBits > 0 && !swStencil) {
         driRenderbuffer *stencilRb
            = driNewRenderbuffer(GL_STENCIL_INDEX8_EXT,
                                 screen->depth.map,
                                 screen->cpp,
                                 screen->depth.offset, screen->depth.pitch,
                                 driDrawPriv);
         intelSetSpanFunctions(stencilRb, mesaVis);
         _mesa_add_renderbuffer(fb, BUFFER_STENCIL, &stencilRb->Base);
      }

      _mesa_add_soft_renderbuffers(fb,
                                   GL_FALSE, /* color */
                                   GL_FALSE, /* depth */
                                   swStencil,
                                   mesaVis->accumRedBits > 0,
                                   GL_FALSE, /* alpha */
                                   GL_FALSE /* aux */);
      driDrawPriv->driverPrivate = (void *) fb;

      return (driDrawPriv->driverPrivate != NULL);
   }
}

static void intelDestroyBuffer(__DRIdrawablePrivate *driDrawPriv)
{
   _mesa_unreference_framebuffer((GLframebuffer **)(&(driDrawPriv->driverPrivate)));
}


/**
 * Get information about previous buffer swaps.
 */
static int
intelGetSwapInfo( __DRIdrawablePrivate *dPriv, __DRIswapInfo * sInfo )
{
   struct intel_context *intel;

   if ( (dPriv == NULL) || (dPriv->driContextPriv == NULL)
	|| (dPriv->driContextPriv->driverPrivate == NULL)
	|| (sInfo == NULL) ) {
      return -1;
   }

   intel = dPriv->driContextPriv->driverPrivate;
   sInfo->swap_count = intel->swap_count;
   sInfo->swap_ust = intel->swap_ust;
   sInfo->swap_missed_count = intel->swap_missed_count;

   sInfo->swap_missed_usage = (sInfo->swap_missed_count != 0)
       ? driCalculateSwapUsage( dPriv, 0, intel->swap_missed_ust )
       : 0.0;

   return 0;
}


/* There are probably better ways to do this, such as an
 * init-designated function to register chipids and createcontext
 * functions.
 */
extern GLboolean i830CreateContext( const __GLcontextModes *mesaVis,
				    __DRIcontextPrivate *driContextPriv,
				    void *sharedContextPrivate);

extern GLboolean i915CreateContext( const __GLcontextModes *mesaVis,
				   __DRIcontextPrivate *driContextPriv,
				   void *sharedContextPrivate);

extern GLboolean brwCreateContext( const __GLcontextModes *mesaVis,
				   __DRIcontextPrivate *driContextPriv,
				   void *sharedContextPrivate);




static GLboolean intelCreateContext( const __GLcontextModes *mesaVis,
				   __DRIcontextPrivate *driContextPriv,
				   void *sharedContextPrivate)
{
#if 0
   __DRIscreenPrivate *sPriv = driContextPriv->driScreenPriv;
   intelScreenPrivate *intelScreen = (intelScreenPrivate *)sPriv->private;
   switch (intelScreen->deviceID) {
   case PCI_CHIP_845_G:
   case PCI_CHIP_I830_M:
   case PCI_CHIP_I855_GM:
   case PCI_CHIP_I865_G:
      return i830CreateContext( mesaVis, driContextPriv, 
				sharedContextPrivate );

   case PCI_CHIP_I915_G:
   case PCI_CHIP_I915_GM:
   case PCI_CHIP_I945_G:
   case PCI_CHIP_I945_GM:
      return i915CreateContext( mesaVis, driContextPriv, 
			       sharedContextPrivate );
 
   default:
      fprintf(stderr, "Unrecognized deviceID %x\n", intelScreen->deviceID);
      return GL_FALSE;
   }
#else
   return brwCreateContext( mesaVis, driContextPriv, 
			    sharedContextPrivate );
#endif
}


static const struct __DriverAPIRec intelAPI = {
   .DestroyScreen   = intelDestroyScreen,
   .CreateContext   = intelCreateContext,
   .DestroyContext  = intelDestroyContext,
   .CreateBuffer    = intelCreateBuffer,
   .DestroyBuffer   = intelDestroyBuffer,
   .SwapBuffers     = intelSwapBuffers,
   .MakeCurrent     = intelMakeCurrent,
   .UnbindContext   = intelUnbindContext,
   .GetSwapInfo     = intelGetSwapInfo,
   .GetMSC          = driGetMSC32,
   .GetDrawableMSC  = driDrawableGetMSC32,
   .WaitForMSC      = driWaitForMSC32,
   .WaitForSBC      = NULL,
   .SwapBuffersMSC  = NULL,
   .CopySubBuffer   = intelCopySubBuffer
};


static __GLcontextModes *
intelFillInModes( unsigned pixel_bits, unsigned depth_bits,
		 unsigned stencil_bits, GLboolean have_back_buffer )
{
   __GLcontextModes * modes;
   __GLcontextModes * m;
   unsigned num_modes;
   unsigned depth_buffer_factor;
   unsigned back_buffer_factor;
   GLenum fb_format;
   GLenum fb_type;

   /* GLX_SWAP_COPY_OML is only supported because the Intel driver doesn't
    * support pageflipping at all.
    */
   static const GLenum back_buffer_modes[] = {
      GLX_NONE, GLX_SWAP_UNDEFINED_OML, GLX_SWAP_COPY_OML
   };

   u_int8_t depth_bits_array[3];
   u_int8_t stencil_bits_array[3];


   depth_bits_array[0] = 0;
   depth_bits_array[1] = depth_bits;
   depth_bits_array[2] = depth_bits;

   /* Just like with the accumulation buffer, always provide some modes
    * with a stencil buffer.  It will be a sw fallback, but some apps won't
    * care about that.
    */
   stencil_bits_array[0] = 0;
   stencil_bits_array[1] = 0;
   stencil_bits_array[2] = (stencil_bits == 0) ? 8 : stencil_bits;

   depth_buffer_factor = ((depth_bits != 0) || (stencil_bits != 0)) ? 3 : 1;
   back_buffer_factor  = (have_back_buffer) ? 3 : 1;

   num_modes = depth_buffer_factor * back_buffer_factor * 4;

    if ( pixel_bits == 16 ) {
        fb_format = GL_RGB;
        fb_type = GL_UNSIGNED_SHORT_5_6_5;
    }
    else {
        fb_format = GL_BGRA;
        fb_type = GL_UNSIGNED_INT_8_8_8_8_REV;
    }

   modes = (*dri_interface->createContextModes)( num_modes, sizeof( __GLcontextModes ) );
   m = modes;
   if ( ! driFillInModes( & m, fb_format, fb_type,
			  depth_bits_array, stencil_bits_array, depth_buffer_factor,
			  back_buffer_modes, back_buffer_factor,
			  GLX_TRUE_COLOR ) ) {
	fprintf( stderr, "[%s:%u] Error creating FBConfig!\n",
		 __func__, __LINE__ );
	return NULL;
   }
   if ( ! driFillInModes( & m, fb_format, fb_type,
			  depth_bits_array, stencil_bits_array, depth_buffer_factor,
			  back_buffer_modes, back_buffer_factor,
			  GLX_DIRECT_COLOR ) ) {
	fprintf( stderr, "[%s:%u] Error creating FBConfig!\n",
		 __func__, __LINE__ );
	return NULL;
   }

   /* Mark the visual as slow if there are "fake" stencil bits.
    */
   for ( m = modes ; m != NULL ; m = m->next ) {
      if ( (m->stencilBits != 0) && (m->stencilBits != stencil_bits) ) {
	 m->visualRating = GLX_SLOW_CONFIG;
      }
   }

   return modes;
}


/**
 * This is the driver specific part of the createNewScreen entry point.
 * 
 * \todo maybe fold this into intelInitDriver
 *
 * \return the __GLcontextModes supported by this driver
 */
__GLcontextModes *__driDriverInitScreen(__DRIscreenPrivate *psp)
{
   static const __DRIversion ddx_expected = { 1, 6, 0 };
   static const __DRIversion dri_expected = { 4, 0, 0 };
   static const __DRIversion drm_expected = { 1, 3, 0 };
   I830DRIPtr dri_priv = (I830DRIPtr) psp->pDevPriv;

   psp->DriverAPI = intelAPI;
   if ( ! driCheckDriDdxDrmVersions2( "i915",
				      &psp->dri_version, &dri_expected,
				      &psp->ddx_version, &ddx_expected,
				      &psp->drm_version, &drm_expected ) ) {
       return NULL;
   }

   /* Calling driInitExtensions here, with a NULL context pointer,
    * does not actually enable the extensions.  It just makes sure
    * that all the dispatch offsets for all the extensions that
    * *might* be enables are known.  This is needed because the
    * dispatch offsets need to be known when _mesa_context_create is
    * called, but we can't enable the extensions until we have a
    * context pointer.
    *
    * Hello chicken.  Hello egg.  How are you two today?
    */
   intelInitExtensions(NULL, GL_FALSE);

   if (!intelInitDriver(psp))
       return NULL;

   return intelFillInModes( dri_priv->cpp * 8,
			    (dri_priv->cpp == 2) ? 16 : 24,
			    (dri_priv->cpp == 2) ? 0  : 8,
			    GL_TRUE );
}