1 files changed, 53 insertions, 24 deletions

diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index 9db58530be37..4973bff37fec 100644
--- a/drivers/gpu/drm/radeon/r100.c
+++ b/drivers/gpu/drm/radeon/r100.c
@@ -69,6 +69,38 @@ MODULE_FIRMWARE(FIRMWARE_R520);
  * and others in some cases.
  */
 
+static bool r100_is_in_vblank(struct radeon_device *rdev, int crtc)
+{
+        if (crtc == 0) {
+                if (RREG32(RADEON_CRTC_STATUS) & RADEON_CRTC_VBLANK_CUR)
+                        return true;
+                else
+                        return false;
+        } else {
+                if (RREG32(RADEON_CRTC2_STATUS) & RADEON_CRTC2_VBLANK_CUR)
+                        return true;
+                else
+                        return false;
+        }
+}
+
+static bool r100_is_counter_moving(struct radeon_device *rdev, int crtc)
+{
+        u32 vline1, vline2;
+
+        if (crtc == 0) {
+                vline1 = (RREG32(RADEON_CRTC_VLINE_CRNT_VLINE) >> 16) & RADEON_CRTC_V_TOTAL;
+                vline2 = (RREG32(RADEON_CRTC_VLINE_CRNT_VLINE) >> 16) & RADEON_CRTC_V_TOTAL;
+        } else {
+                vline1 = (RREG32(RADEON_CRTC2_VLINE_CRNT_VLINE) >> 16) & RADEON_CRTC_V_TOTAL;
+                vline2 = (RREG32(RADEON_CRTC2_VLINE_CRNT_VLINE) >> 16) & RADEON_CRTC_V_TOTAL;
+        }
+        if (vline1 != vline2)
+                return true;
+        else
+                return false;
+}
+
 /**
  * r100_wait_for_vblank - vblank wait asic callback.
  *
@@ -79,36 +111,33 @@ MODULE_FIRMWARE(FIRMWARE_R520);
  */
 void r100_wait_for_vblank(struct radeon_device *rdev, int crtc)
 {
-        int i;
+        unsigned i = 0;
 
         if (crtc >= rdev->num_crtc)
                 return;
 
         if (crtc == 0) {
-                if (RREG32(RADEON_CRTC_GEN_CNTL) & RADEON_CRTC_EN) {
-                        for (i = 0; i < rdev->usec_timeout; i++) {
-                                if (!(RREG32(RADEON_CRTC_STATUS) & RADEON_CRTC_VBLANK_CUR))
-                                        break;
-                                udelay(1);
-                        }
-                        for (i = 0; i < rdev->usec_timeout; i++) {
-                                if (RREG32(RADEON_CRTC_STATUS) & RADEON_CRTC_VBLANK_CUR)
-                                        break;
-                                udelay(1);
-                        }
-                }
+                if (!(RREG32(RADEON_CRTC_GEN_CNTL) & RADEON_CRTC_EN))
+                        return;
         } else {
-                if (RREG32(RADEON_CRTC2_GEN_CNTL) & RADEON_CRTC2_EN) {
-                        for (i = 0; i < rdev->usec_timeout; i++) {
-                                if (!(RREG32(RADEON_CRTC2_STATUS) & RADEON_CRTC2_VBLANK_CUR))
-                                        break;
-                                udelay(1);
-                        }
-                        for (i = 0; i < rdev->usec_timeout; i++) {
-                                if (RREG32(RADEON_CRTC2_STATUS) & RADEON_CRTC2_VBLANK_CUR)
-                                        break;
-                                udelay(1);
-                        }
+                if (!(RREG32(RADEON_CRTC2_GEN_CNTL) & RADEON_CRTC2_EN))
+                        return;
+        }
+
+        /* depending on when we hit vblank, we may be close to active; if so,
+         * wait for another frame.
+         */
+        while (r100_is_in_vblank(rdev, crtc)) {
+                if (i++ % 100 == 0) {
+                        if (!r100_is_counter_moving(rdev, crtc))
+                                break;
+                }
+        }
+
+        while (!r100_is_in_vblank(rdev, crtc)) {
+                if (i++ % 100 == 0) {
+                        if (!r100_is_counter_moving(rdev, crtc))
+                                break;
                 }
         }
 }