MSI_REARM_EN register is a write only trigger register.
There is no need RMW when re-arming.
May fix:
https://bugs.freedesktop.org/show_bug.cgi?id=41668
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
CC: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
                        WREG32(RADEON_AIC_CNTL, msi_rearm | RS400_MSI_REARM);
                        break;
                default:
-                       msi_rearm = RREG32(RADEON_MSI_REARM_EN) & ~RV370_MSI_REARM_EN;
-                       WREG32(RADEON_MSI_REARM_EN, msi_rearm);
-                       WREG32(RADEON_MSI_REARM_EN, msi_rearm | RV370_MSI_REARM_EN);
+                       WREG32(RADEON_MSI_REARM_EN, RV370_MSI_REARM_EN);
                        break;
                }
        }
 
                        WREG32(RADEON_BUS_CNTL, msi_rearm | RS600_MSI_REARM);
                        break;
                default:
-                       msi_rearm = RREG32(RADEON_MSI_REARM_EN) & ~RV370_MSI_REARM_EN;
-                       WREG32(RADEON_MSI_REARM_EN, msi_rearm);
-                       WREG32(RADEON_MSI_REARM_EN, msi_rearm | RV370_MSI_REARM_EN);
+                       WREG32(RADEON_MSI_REARM_EN, RV370_MSI_REARM_EN);
                        break;
                }
        }