These bits are used for internal communication and should
be left enabled.  This may fix s/r issues on some systems.
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
 {
        u32 tmp;
 
-       WREG32(CP_INT_CNTL, 0);
+       WREG32(CP_INT_CNTL, CNTX_BUSY_INT_ENABLE | CNTX_EMPTY_INT_ENABLE);
        WREG32(GRBM_INT_CNTL, 0);
        WREG32(INT_MASK + EVERGREEN_CRTC0_REGISTER_OFFSET, 0);
        WREG32(INT_MASK + EVERGREEN_CRTC1_REGISTER_OFFSET, 0);
 
 {
        u32 tmp;
 
-       WREG32(CP_INT_CNTL, 0);
+       WREG32(CP_INT_CNTL, CNTX_BUSY_INT_ENABLE | CNTX_EMPTY_INT_ENABLE);
        WREG32(GRBM_INT_CNTL, 0);
        WREG32(DxMODE_INT_MASK, 0);
        if (ASIC_IS_DCE3(rdev)) {