While the apg_end address is 0xffffffff, if add 1 with it, the value will be
overflow and roll back to 0. So when 0 is written to
mmMC_VM_SYSTEM_APERTURE_HIGH_ADDR, the system aperture is actually disabled. And
so any access to vram will trigger a page fault.
Raven2's HW issue only need increase the vram end address, and needn't do it on
the agp.
Signed-off-by: Huang Rui <ray.huang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Cc: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
                 * to get rid of the VM fault and hardware hang.
                 */
                WREG32_SOC15(GC, 0, mmMC_VM_SYSTEM_APERTURE_HIGH_ADDR,
-                            (max(adev->gmc.vram_end, adev->gmc.agp_end) >> 18) + 0x1);
+                            max((adev->gmc.vram_end >> 18) + 0x1,
+                                adev->gmc.agp_end >> 18));
        else
                WREG32_SOC15(GC, 0, mmMC_VM_SYSTEM_APERTURE_HIGH_ADDR,
                             max(adev->gmc.vram_end, adev->gmc.agp_end) >> 18);
 
                 * to get rid of the VM fault and hardware hang.
                 */
                WREG32_SOC15(MMHUB, 0, mmMC_VM_SYSTEM_APERTURE_HIGH_ADDR,
-                            (max(adev->gmc.vram_end, adev->gmc.agp_end) >> 18) + 0x1);
+                            max((adev->gmc.vram_end >> 18) + 0x1,
+                                adev->gmc.agp_end >> 18));
        else
                WREG32_SOC15(MMHUB, 0, mmMC_VM_SYSTEM_APERTURE_HIGH_ADDR,
                             max(adev->gmc.vram_end, adev->gmc.agp_end) >> 18);