radeon: fix frontbuffer read/drawpixels

Bug 25699

The main problem was the optimising flush wasn't doing the front
rendering checks properly.

5 files changed, 58 insertions, 16 deletions

diff --git a/src/mesa/drivers/dri/r600/r700_clear.c b/src/mesa/drivers/dri/r600/r700_clear.c
index c6546ab00c..526d3843d1 100644
--- a/src/mesa/drivers/dri/r600/r700_clear.c
+++ b/src/mesa/drivers/dri/r600/r700_clear.c
@@ -57,6 +57,10 @@ void r700Clear(GLcontext * ctx, GLbitfield mask)
 
     radeon_print(RADEON_RENDER, RADEON_VERBOSE, "%s %x\n", __func__, mask);
 
+    if (mask & (BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT)) {
+        context->radeon.front_buffer_dirty = GL_TRUE;
+    }
+
     if( GL_TRUE == r700ClearFast(context, mask) )
     {
         return;
diff --git a/src/mesa/drivers/dri/radeon/radeon_common.c b/src/mesa/drivers/dri/radeon/radeon_common.c
index 51fa618937..2a2b16a54b 100644
--- a/src/mesa/drivers/dri/radeon/radeon_common.c
+++ b/src/mesa/drivers/dri/radeon/radeon_common.c
@@ -641,6 +641,27 @@ void radeonCopySubBuffer(__DRIdrawablePrivate * dPriv,
 	}
 }
 
+/**
+ * Check if we're about to draw into the front color buffer.
+ * If so, set the intel->front_buffer_dirty field to true.
+ */
+void
+radeon_check_front_buffer_rendering(GLcontext *ctx)
+{
+	radeonContextPtr radeon = RADEON_CONTEXT(ctx);
+	const struct gl_framebuffer *fb = ctx->DrawBuffer;
+
+	if (fb->Name == 0) {
+		/* drawing to window system buffer */
+		if (fb->_NumColorDrawBuffers > 0) {
+			if (fb->_ColorDrawBufferIndexes[0] == BUFFER_FRONT_LEFT) {
+				radeon->front_buffer_dirty = GL_TRUE;
+			}
+		}
+	}
+}
+
+
 void radeon_draw_buffer(GLcontext *ctx, struct gl_framebuffer *fb)
 {
 	radeonContextPtr radeon = RADEON_CONTEXT(ctx);
@@ -1095,7 +1116,7 @@ void radeonFlush(GLcontext *ctx)
 	   then no point flushing anything at all.
 	*/
 	if (!radeon->dma.flush && !radeon->cmdbuf.cs->cdw && is_empty_list(&radeon->dma.reserved))
-		return;
+		goto flush_front;
 
 	if (radeon->dma.flush)
 		radeon->dma.flush( ctx );
@@ -1103,6 +1124,7 @@ void radeonFlush(GLcontext *ctx)
 	if (radeon->cmdbuf.cs->cdw)
 		rcommonFlushCmdBuf(radeon, __FUNCTION__);
 
+flush_front:
 	if ((ctx->DrawBuffer->Name == 0) && radeon->front_buffer_dirty) {
 		__DRIscreen *const screen = radeon->radeonScreen->driScreen;
 
diff --git a/src/mesa/drivers/dri/radeon/radeon_common.h b/src/mesa/drivers/dri/radeon/radeon_common.h
index 0608fe2418..faad145cc4 100644
--- a/src/mesa/drivers/dri/radeon/radeon_common.h
+++ b/src/mesa/drivers/dri/radeon/radeon_common.h
@@ -43,6 +43,8 @@ radeon_renderbuffer_set_bo(struct radeon_renderbuffer *rb,
 			   struct radeon_bo *bo);
 struct radeon_renderbuffer *
 radeon_create_renderbuffer(gl_format format, __DRIdrawablePrivate *driDrawPriv);
+
+void radeon_check_front_buffer_rendering(GLcontext *ctx);
 static inline struct radeon_renderbuffer *radeon_renderbuffer(struct gl_renderbuffer *rb)
 {
 	struct radeon_renderbuffer *rrb = (struct radeon_renderbuffer *)rb;
diff --git a/src/mesa/drivers/dri/radeon/radeon_ioctl.c b/src/mesa/drivers/dri/radeon/radeon_ioctl.c
index a0106d00fa..13fd6f9971 100644
--- a/src/mesa/drivers/dri/radeon/radeon_ioctl.c
+++ b/src/mesa/drivers/dri/radeon/radeon_ioctl.c
@@ -575,6 +575,10 @@ static void radeonClear( GLcontext *ctx, GLbitfield mask )
    GLuint color_mask = 0;
    GLuint orig_mask = mask;
 
+   if (mask & (BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT)) {
+      rmesa->radeon.front_buffer_dirty = GL_TRUE;
+   }
+
    if ( RADEON_DEBUG & RADEON_IOCTL ) {
       fprintf( stderr, "radeonClear\n");
    }
diff --git a/src/mesa/drivers/dri/radeon/radeon_span.c b/src/mesa/drivers/dri/radeon/radeon_span.c
index 37904dc8dc..cffe840662 100644
--- a/src/mesa/drivers/dri/radeon/radeon_span.c
+++ b/src/mesa/drivers/dri/radeon/radeon_span.c
@@ -828,18 +828,21 @@ static void map_unmap_rb(struct gl_renderbuffer *rb, int flag)
 }
 
 static void
-radeon_map_unmap_buffers(GLcontext *ctx, GLboolean map)
+radeon_map_unmap_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb,
+			     GLboolean map)
 {
 	GLuint i, j;
 
 	/* color draw buffers */
 	for (j = 0; j < ctx->DrawBuffer->_NumColorDrawBuffers; j++)
-		map_unmap_rb(ctx->DrawBuffer->_ColorDrawBuffers[j], map);
+		map_unmap_rb(fb->_ColorDrawBuffers[j], map);
+
+	map_unmap_rb(fb->_ColorReadBuffer, map);
 
 	/* check for render to textures */
 	for (i = 0; i < BUFFER_COUNT; i++) {
 		struct gl_renderbuffer_attachment *att =
-			ctx->DrawBuffer->Attachment + i;
+			fb->Attachment + i;
 		struct gl_texture_object *tex = att->Texture;
 		if (tex) {
 			/* Render to texture. Note that a mipmapped texture need not
@@ -855,15 +858,15 @@ radeon_map_unmap_buffers(GLcontext *ctx, GLboolean map)
 				radeon_teximage_unmap(image);
 		}
 	}
-
-	map_unmap_rb(ctx->ReadBuffer->_ColorReadBuffer, map);
-
+	
 	/* depth buffer (Note wrapper!) */
-	if (ctx->DrawBuffer->_DepthBuffer)
-		map_unmap_rb(ctx->DrawBuffer->_DepthBuffer->Wrapped, map);
+	if (fb->_DepthBuffer)
+		map_unmap_rb(fb->_DepthBuffer->Wrapped, map);
+
+	if (fb->_StencilBuffer)
+		map_unmap_rb(fb->_StencilBuffer->Wrapped, map);
 
-	if (ctx->DrawBuffer->_StencilBuffer)
-		map_unmap_rb(ctx->DrawBuffer->_StencilBuffer->Wrapped, map);
+	radeon_check_front_buffer_rendering(ctx);
 }
 
 static void radeonSpanRenderStart(GLcontext * ctx)
@@ -888,23 +891,30 @@ static void radeonSpanRenderStart(GLcontext * ctx)
 			ctx->Driver.MapTexture(ctx, ctx->Texture.Unit[i]._Current);
 	}
 
-	radeon_map_unmap_buffers(ctx, 1);
+	radeon_map_unmap_framebuffer(ctx, ctx->DrawBuffer, GL_TRUE);
+	if (ctx->ReadBuffer != ctx->DrawBuffer)
+		radeon_map_unmap_framebuffer(ctx, ctx->ReadBuffer, GL_TRUE);
 }
 
 static void radeonSpanRenderFinish(GLcontext * ctx)
 {
 	radeonContextPtr rmesa = RADEON_CONTEXT(ctx);
 	int i;
+
 	_swrast_flush(ctx);
-	if (!rmesa->radeonScreen->driScreen->dri2.enabled) {
-		UNLOCK_HARDWARE(rmesa);
-	}
+
 	for (i = 0; i < ctx->Const.MaxTextureImageUnits; i++) {
 		if (ctx->Texture.Unit[i]._ReallyEnabled)
 			ctx->Driver.UnmapTexture(ctx, ctx->Texture.Unit[i]._Current);
 	}
 
-	radeon_map_unmap_buffers(ctx, 0);
+	radeon_map_unmap_framebuffer(ctx, ctx->DrawBuffer, GL_FALSE);
+	if (ctx->ReadBuffer != ctx->DrawBuffer)
+		radeon_map_unmap_framebuffer(ctx, ctx->ReadBuffer, GL_FALSE);
+
+	if (!rmesa->radeonScreen->driScreen->dri2.enabled) {
+		UNLOCK_HARDWARE(rmesa);
+	}
 }
 
 void radeonInitSpanFuncs(GLcontext * ctx)