Set the write combine flag for the framebuffer area.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36330 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/kernel/drivers/graphics/radeon_hd/Jamfile

@@ -6,6 +6,7 @@ UsePrivateHeaders [ FDirName graphics radeon_hd ] ;
 UsePrivateHeaders [ FDirName graphics common ] ;
 UsePrivateHeaders graphics kernel ;
 UsePrivateHeaders shared ;
+UsePrivateKernelHeaders ;
 
 KernelAddon radeon_hd :
 	driver.cpp

src/add-ons/kernel/drivers/graphics/radeon_hd/radeon_hd.cpp

@@ -20,6 +20,7 @@
 
 #include <driver_settings.h>
 #include <util/kernel_cpp.h>
+#include <vm/vm.h>
 
 
 #define TRACE_DEVICE
@@ -232,6 +233,10 @@ radeon_hd_init(radeon_info &info)
 		return info.framebuffer_area;
 	}
 	
+	// Turn on write combining for the area
+	vm_set_area_memory_type(info.framebuffer_area,
+		info.pci->u.h0.base_registers[RHD_FB_BAR], B_MTR_WC);
+	
 	sharedCreator.Detach();
 	mmioMapper.Detach();
 	frambufferMapper.Detach();