1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 42111e6b5282..d425a4fa0109 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -1574,6 +1574,7 @@ void evergreen_mc_stop(struct radeon_device *rdev, struct evergreen_mc_save *sav
                                 tmp = RREG32(EVERGREEN_CRTC_BLANK_CONTROL + crtc_offsets[i]);
                                 if (!(tmp & EVERGREEN_CRTC_BLANK_DATA_EN)) {
                                         radeon_wait_for_vblank(rdev, i);
+                                        WREG32(EVERGREEN_CRTC_UPDATE_LOCK + crtc_offsets[i], 1);
                                         tmp |= EVERGREEN_CRTC_BLANK_DATA_EN;
                                         WREG32(EVERGREEN_CRTC_BLANK_CONTROL + crtc_offsets[i], tmp);
                                 }
@@ -1581,8 +1582,10 @@ void evergreen_mc_stop(struct radeon_device *rdev, struct evergreen_mc_save *sav
                                 tmp = RREG32(EVERGREEN_CRTC_CONTROL + crtc_offsets[i]);
                                 if (!(tmp & EVERGREEN_CRTC_DISP_READ_REQUEST_DISABLE)) {
                                         radeon_wait_for_vblank(rdev, i);
+                                        WREG32(EVERGREEN_CRTC_UPDATE_LOCK + crtc_offsets[i], 1);
                                         tmp |= EVERGREEN_CRTC_DISP_READ_REQUEST_DISABLE;
                                         WREG32(EVERGREEN_CRTC_CONTROL + crtc_offsets[i], tmp);
+                                        WREG32(EVERGREEN_CRTC_UPDATE_LOCK + crtc_offsets[i], 0);
                                 }
                         }
                         /* wait for the next frame */
@@ -1592,6 +1595,15 @@ void evergreen_mc_stop(struct radeon_device *rdev, struct evergreen_mc_save *sav
                                         break;
                                 udelay(1);
                         }
+
+                        /* XXX this is a hack to avoid strange behavior with EFI on certain systems */
+                        WREG32(EVERGREEN_CRTC_UPDATE_LOCK + crtc_offsets[i], 1);
+                        tmp = RREG32(EVERGREEN_CRTC_CONTROL + crtc_offsets[i]);
+                        tmp &= ~EVERGREEN_CRTC_MASTER_EN;
+                        WREG32(EVERGREEN_CRTC_CONTROL + crtc_offsets[i], tmp);
+                        WREG32(EVERGREEN_CRTC_UPDATE_LOCK + crtc_offsets[i], 0);
+                        save->crtc_enabled[i] = false;
+                        /* ***** */
                 } else {
                         save->crtc_enabled[i] = false;
                 }