drm/radeon/kms: fix vram base calculation on rs780/rs880

Avoid overflowing a 32 bit value.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 4 insertions, 2 deletions

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index a3552594ccc4..a322d4f647bd 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1195,8 +1195,10 @@ void r600_vram_gtt_location(struct radeon_device *rdev, struct radeon_mc *mc)
                                 mc->vram_end, mc->real_vram_size >> 20);
         } else {
                 u64 base = 0;
-                if (rdev->flags & RADEON_IS_IGP)
-                        base = (RREG32(MC_VM_FB_LOCATION) & 0xFFFF) << 24;
+                if (rdev->flags & RADEON_IS_IGP) {
+                        base = RREG32(MC_VM_FB_LOCATION) & 0xFFFF;
+                        base <<= 24;
+                }
                 radeon_vram_location(rdev, &rdev->mc, base);
                 rdev->mc.gtt_base_align = 0;
                 radeon_gtt_location(rdev, mc);