drm/radeon/kms: disable VGA rendering engine before taking over VRAM
Before we use any of VRAM, we need to disable the VGA rendering
engine, this render text mode into a graphical framebuffer
for scanout, however it does this on vblank, and can end up
overwriting the GART table and r600 shader objects.
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/avivod.h b/drivers/gpu/drm/radeon/avivod.h
index d4e6e6e..e2b92c4 100644
--- a/drivers/gpu/drm/radeon/avivod.h
+++ b/drivers/gpu/drm/radeon/avivod.h
@@ -57,4 +57,13 @@
#define VGA_RENDER_CONTROL 0x0300
#define VGA_VSTATUS_CNTL_MASK 0x00030000
+/* AVIVO disable VGA rendering */
+static inline void radeon_avivo_vga_render_disable(struct radeon_device *rdev)
+{
+ u32 vga_render;
+ vga_render = RREG32(VGA_RENDER_CONTROL);
+ vga_render &= ~VGA_VSTATUS_CNTL_MASK;
+ WREG32(VGA_RENDER_CONTROL, vga_render);
+}
+
#endif