1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/gpu/drm/radeon/rs600.c b/drivers/gpu/drm/radeon/rs600.c
index 670b555d2ca2..6acba8017b9a 100644
--- a/drivers/gpu/drm/radeon/rs600.c
+++ b/drivers/gpu/drm/radeon/rs600.c
@@ -847,16 +847,26 @@ void rs600_bandwidth_update(struct radeon_device *rdev)
 
 uint32_t rs600_mc_rreg(struct radeon_device *rdev, uint32_t reg)
 {
+        unsigned long flags;
+        u32 r;
+
+        spin_lock_irqsave(&rdev->mc_idx_lock, flags);
         WREG32(R_000070_MC_IND_INDEX, S_000070_MC_IND_ADDR(reg) |
                 S_000070_MC_IND_CITF_ARB0(1));
-        return RREG32(R_000074_MC_IND_DATA);
+        r = RREG32(R_000074_MC_IND_DATA);
+        spin_unlock_irqrestore(&rdev->mc_idx_lock, flags);
+        return r;
 }
 
 void rs600_mc_wreg(struct radeon_device *rdev, uint32_t reg, uint32_t v)
 {
+        unsigned long flags;
+
+        spin_lock_irqsave(&rdev->mc_idx_lock, flags);
         WREG32(R_000070_MC_IND_INDEX, S_000070_MC_IND_ADDR(reg) |
                 S_000070_MC_IND_CITF_ARB0(1) | S_000070_MC_IND_WR_EN(1));
         WREG32(R_000074_MC_IND_DATA, v);
+        spin_unlock_irqrestore(&rdev->mc_idx_lock, flags);
 }
 
 static void rs600_debugfs(struct radeon_device *rdev)