/* r7xx hw bug. write to HDP_DEBUG1 followed by fb read
* rather than write to HDP_REG_COHERENCY_FLUSH_CNTL
*/
- if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740)) {
+ if ((rdev->family >= CHIP_RV770) && (rdev->family <= CHIP_RV740) &&
+ rdev->vram_scratch.ptr) {
void __iomem *ptr = (void *)rdev->vram_scratch.ptr;
u32 tmp;