Add Option "DepthBits".

This allows getting higher depth buffer precision and stencil hardware
acceleration in depth 16 or saving some video RAM at the cost of these features
in depth 24.

5 files changed, 54 insertions, 16 deletions

diff --git a/man/radeon.man b/man/radeon.man
index 2bbd431..55f83ad 100644
--- a/man/radeon.man
+++ b/man/radeon.man
@@ -518,6 +518,14 @@ reserved for textures to the amount specified roughly.
 Default:
 .B 50.
 .TP
+.BI "Option \*qDepthBits\*q \*q" integer \*q
+Precision in bits per pixel of the shared depth buffer used for 3D acceleration.
+Valid values are 16 and 24. When this is 24, there will also be a hardware
+accelerated stencil buffer, but the combined depth/stencil buffer will take up
+twice as much video RAM as when it's 16.
+Default:
+.B The same as the screen depth.
+.TP
 .BI "Option \*qDMAForXv\*q \*q" boolean \*q
 Try or don't try to use DMA for Xv image transfers. This will reduce CPU
 usage when playing big videos like DVDs, but may cause instabilities.
diff --git a/src/radeon.h b/src/radeon.h
index 7f1e0ad..06b3409 100644
--- a/src/radeon.h
+++ b/src/radeon.h
@@ -584,6 +584,7 @@ typedef struct {
     int               backPitch;
     int               depthOffset;
     int               depthPitch;
+    int               depthBits;
     int               textureOffset;
     int               textureSize;
     int               log2TexGran;
diff --git a/src/radeon_dri.c b/src/radeon_dri.c
index bbc858a..1e0d544 100644
--- a/src/radeon_dri.c
+++ b/src/radeon_dri.c
@@ -162,14 +162,15 @@ static Bool RADEONInitVisualConfigs(ScreenPtr pScreen)
 		    pConfigs[i].doubleBuffer   = FALSE;
 		pConfigs[i].stereo             = FALSE;
 		pConfigs[i].bufferSize         = 16;
-		pConfigs[i].depthSize          = 16;
+		pConfigs[i].depthSize          = info->depthBits;
 		if (stencil)
 		    pConfigs[i].stencilSize    = 8;
 		else
 		    pConfigs[i].stencilSize    = 0;
 		pConfigs[i].auxBuffers         = 0;
 		pConfigs[i].level              = 0;
-		if (accum || stencil) {
+		if (accum ||
+		    (pConfigs[i].stencilSize && pConfigs[i].depthSize == 16)) {
 		   pConfigs[i].visualRating    = GLX_SLOW_CONFIG;
 		} else {
 		   pConfigs[i].visualRating    = GLX_NONE;
@@ -245,16 +246,16 @@ static Bool RADEONInitVisualConfigs(ScreenPtr pScreen)
 		    pConfigs[i].doubleBuffer   = FALSE;
 		pConfigs[i].stereo             = FALSE;
 		pConfigs[i].bufferSize         = 32;
+		pConfigs[i].depthSize          = info->depthBits;
 		if (stencil) {
-		    pConfigs[i].depthSize      = 24;
 		    pConfigs[i].stencilSize    = 8;
 		} else {
-		    pConfigs[i].depthSize      = 24;
 		    pConfigs[i].stencilSize    = 0;
 		}
 		pConfigs[i].auxBuffers         = 0;
 		pConfigs[i].level              = 0;
-		if (accum) {
+		if (accum ||
+		    (pConfigs[i].stencilSize && pConfigs[i].depthSize == 16)) {
 		   pConfigs[i].visualRating    = GLX_SLOW_CONFIG;
 		} else {
 		   pConfigs[i].visualRating    = GLX_NONE;
@@ -1061,14 +1062,14 @@ static int RADEONDRIKernelInit(RADEONInfoPtr info, ScreenPtr pScreen)
     drmInfo.usec_timeout        = info->CPusecTimeout;
 
     drmInfo.fb_bpp              = info->CurrentLayout.pixel_code;
-    drmInfo.depth_bpp           = info->CurrentLayout.pixel_code;
+    drmInfo.depth_bpp           = (info->depthBits - 8) * 2;
 
     drmInfo.front_offset        = info->frontOffset;
     drmInfo.front_pitch         = info->frontPitch * cpp;
     drmInfo.back_offset         = info->backOffset;
     drmInfo.back_pitch          = info->backPitch * cpp;
     drmInfo.depth_offset        = info->depthOffset;
-    drmInfo.depth_pitch         = info->depthPitch * cpp;
+    drmInfo.depth_pitch         = info->depthPitch * drmInfo.depth_bpp / 8;
 
     drmInfo.fb_offset           = info->fbHandle;
     drmInfo.mmio_offset         = info->registerHandle;
diff --git a/src/radeon_driver.c b/src/radeon_driver.c
index 54a868a..ff2dba7 100644
--- a/src/radeon_driver.c
+++ b/src/radeon_driver.c
@@ -161,6 +161,7 @@ typedef enum {
     OPTION_NO_BACKBUFFER,
     OPTION_XV_DMA,
     OPTION_FBTEX_PERCENT,
+    OPTION_DEPTH_BITS,
 #endif
     OPTION_PANEL_OFF,
     OPTION_DDC_MODE,
@@ -225,6 +226,7 @@ static const OptionInfoRec RADEONOptions[] = {
     { OPTION_NO_BACKBUFFER,  "NoBackBuffer",     OPTV_BOOLEAN, {0}, FALSE },
     { OPTION_XV_DMA,         "DMAForXv",         OPTV_BOOLEAN, {0}, FALSE },
     { OPTION_FBTEX_PERCENT,  "FBTexPercent",     OPTV_INTEGER, {0}, FALSE },
+    { OPTION_DEPTH_BITS,     "DepthBits",        OPTV_INTEGER, {0}, FALSE },
 #endif
     { OPTION_PANEL_OFF,      "PanelOff",         OPTV_BOOLEAN, {0}, FALSE },
     { OPTION_DDC_MODE,       "DDCMode",          OPTV_BOOLEAN, {0}, FALSE },
@@ -5364,6 +5366,7 @@ Bool RADEONSetupMemXAA_DRI(int scrnIndex, ScreenPtr pScreen)
     ScrnInfoPtr    pScrn = xf86Screens[pScreen->myNum];
     RADEONInfoPtr  info  = RADEONPTR(pScrn);
     int            cpp = info->CurrentLayout.pixel_bytes;
+    int            depthCpp = (info->depthBits - 8) / 4;
     int            width_bytes = pScrn->displayWidth * cpp;
     int            bufferSize;
     int            depthSize;
@@ -5394,7 +5397,7 @@ Bool RADEONSetupMemXAA_DRI(int scrnIndex, ScreenPtr pScreen)
      */
     info->depthPitch = (pScrn->displayWidth + 31) & ~31;
     depthSize = ((((pScrn->virtualY + 15) & ~15) * info->depthPitch
-		  * cpp + RADEON_BUFFER_ALIGN) & ~RADEON_BUFFER_ALIGN);
+		  * depthCpp + RADEON_BUFFER_ALIGN) & ~RADEON_BUFFER_ALIGN);
 
     switch (info->CPMode) {
     case RADEON_DEFAULT_CP_PIO_MODE:
@@ -5620,7 +5623,7 @@ Bool RADEONSetupMemXAA_DRI(int scrnIndex, ScreenPtr pScreen)
     info->backPitchOffset = (((info->backPitch * cpp / 64) << 22) |
 			     ((info->backOffset + info->fbLocation) >> 10));
 
-    info->depthPitchOffset = (((info->depthPitch * cpp / 64) << 22) |
+    info->depthPitchOffset = (((info->depthPitch * depthCpp / 64) << 22) |
 			      ((info->depthOffset + info->fbLocation) >> 10));
     return TRUE;
 }
@@ -5755,6 +5758,26 @@ _X_EXPORT Bool RADEONScreenInit(int scrnIndex, ScreenPtr pScreen,
     miSetPixmapDepths ();
 
 #ifdef XF86DRI
+    if (info->directRenderingEnabled) {
+	MessageType from;
+
+	info->depthBits = pScrn->depth;
+
+	from = xf86GetOptValInteger(info->Options, OPTION_DEPTH_BITS,
+				    &info->depthBits)
+	     ? X_CONFIG : X_DEFAULT;
+
+	if (info->depthBits != 16 && info->depthBits != 24) {
+	    xf86DrvMsg(pScrn->scrnIndex, X_ERROR,
+		       "Value for Option \"DepthBits\" must be 16 or 24\n");
+	    info->depthBits = pScrn->depth;
+	    from = X_DEFAULT;
+	}
+
+	xf86DrvMsg(pScrn->scrnIndex, from,
+		   "Using %d bit depth buffer\n", info->depthBits);
+    }
+
     /* Setup DRI after visuals have been established, but before fbScreenInit is
      * called.  fbScreenInit will eventually call the driver's InitGLXVisuals
      * call back. */
@@ -6810,10 +6833,14 @@ void RADEONChangeSurfaces(ScrnInfoPtr pScrn)
   
     RADEONInfoPtr  info  = RADEONPTR(pScrn);
     int cpp = info->CurrentLayout.pixel_bytes;
+    int depthCpp = (info->depthBits - 8) / 4;
     /* depth/front/back pitch must be identical (and the same as displayWidth) */
     int width_bytes = pScrn->displayWidth * cpp;
     int bufferSize = ((((pScrn->virtualY + 15) & ~15) * width_bytes
         + RADEON_BUFFER_ALIGN) & ~RADEON_BUFFER_ALIGN);
+    int depth_width_bytes = pScrn->displayWidth * depthCpp;
+    int depthBufferSize = ((((pScrn->virtualY + 15) & ~15) * depth_width_bytes
+        + RADEON_BUFFER_ALIGN) & ~RADEON_BUFFER_ALIGN);
     unsigned int depth_pattern, color_pattern, swap_pattern;
 
     if (!info->allowColorTiling)
@@ -6833,19 +6860,19 @@ void RADEONChangeSurfaces(ScrnInfoPtr pScrn)
 #endif
     if (info->ChipFamily < CHIP_FAMILY_R200) {
 	color_pattern = RADEON_SURF_TILE_COLOR_MACRO;
-	if (cpp == 2)
+	if (depthCpp == 2)
 	    depth_pattern = RADEON_SURF_TILE_DEPTH_16BPP;
 	else
 	    depth_pattern = RADEON_SURF_TILE_DEPTH_32BPP;
     } else if (IS_R300_VARIANT) {
        color_pattern = R300_SURF_TILE_COLOR_MACRO;
-       if (cpp == 2)
+       if (depthCpp == 2)
            depth_pattern = R300_SURF_TILE_COLOR_MACRO;
        else
            depth_pattern = R300_SURF_TILE_COLOR_MACRO | R300_SURF_TILE_DEPTH_32BPP;
     } else {
 	color_pattern = R200_SURF_TILE_COLOR_MACRO;
-	if (cpp == 2)
+	if (depthCpp == 2)
 	    depth_pattern = R200_SURF_TILE_DEPTH_16BPP;
 	else
 	    depth_pattern = R200_SURF_TILE_DEPTH_32BPP;
@@ -6904,12 +6931,12 @@ void RADEONChangeSurfaces(ScrnInfoPtr pScrn)
 	    (info->ChipFamily != CHIP_FAMILY_RS100) ||
 	    (info->ChipFamily != CHIP_FAMILY_RS200))) {
 	    drmRadeonSurfaceAlloc drmsurfalloc;
-	    drmsurfalloc.size = bufferSize;
+	    drmsurfalloc.size = depthBufferSize;
 	    drmsurfalloc.address = info->depthOffset;
             if (IS_R300_VARIANT)
-                drmsurfalloc.flags = swap_pattern | (width_bytes / 8) | depth_pattern;
+                drmsurfalloc.flags = swap_pattern | (depth_width_bytes / 8) | depth_pattern;
             else
-                drmsurfalloc.flags = swap_pattern | (width_bytes / 16) | depth_pattern;
+                drmsurfalloc.flags = swap_pattern | (depth_width_bytes / 16) | depth_pattern;
 	    retvalue = drmCommandWrite(info->drmFD, DRM_RADEON_SURF_ALLOC,
 		&drmsurfalloc, sizeof(drmsurfalloc));
 	    if (retvalue < 0)
diff --git a/src/radeon_exa.c b/src/radeon_exa.c
index 8070da1..0cf86f5 100644
--- a/src/radeon_exa.c
+++ b/src/radeon_exa.c
@@ -367,6 +367,7 @@ Bool RADEONSetupMemEXA (ScreenPtr pScreen)
     ScrnInfoPtr pScrn = xf86Screens[pScreen->myNum];
     RADEONInfoPtr info = RADEONPTR(pScrn);
     int cpp = info->CurrentLayout.pixel_bytes;
+    int depthCpp = (info->depthBits - 8) / 4;
     int l;
     int next, screen_size;
     int byteStride = pScrn->displayWidth * cpp;
@@ -435,7 +436,7 @@ Bool RADEONSetupMemEXA (ScreenPtr pScreen)
 	 * handle tiling.
 	 */
 	info->depthPitch = RADEON_ALIGN(pScrn->displayWidth, 32);
-	depth_size = RADEON_ALIGN(pScrn->virtualY, 16) * info->depthPitch * cpp;
+	depth_size = RADEON_ALIGN(pScrn->virtualY, 16) * info->depthPitch * depthCpp;
 	next = RADEON_ALIGN(info->exa->offScreenBase, RADEON_BUFFER_ALIGN);
 	if (next + depth_size <= info->exa->memorySize)
 	{