2 files changed, 24 insertions, 23 deletions

diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index e55619f49671..c2676b5908d9 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -542,7 +542,7 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
 {
         ktime_t stime, etime, mono_time_offset;
         struct timeval tv_etime;
-        int vbl_status, vtotal, vdisplay;
+        int vbl_status;
         int vpos, hpos, i;
         int framedur_ns, linedur_ns, pixeldur_ns, delta_ns, duration_ns;
         bool invbl;
@@ -558,9 +558,6 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
                 return -EIO;
         }
 
-        vtotal = mode->crtc_vtotal;
-        vdisplay = mode->crtc_vdisplay;
-
         /* Durations of frames, lines, pixels in nanoseconds. */
         framedur_ns = refcrtc->framedur_ns;
         linedur_ns  = refcrtc->linedur_ns;
@@ -569,7 +566,7 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
         /* If mode timing undefined, just return as no-op:
          * Happens during initial modesetting of a crtc.
          */
-        if (vtotal <= 0 || vdisplay <= 0 || framedur_ns == 0) {
+        if (framedur_ns == 0) {
                 DRM_DEBUG("crtc %d: Noop due to uninitialized mode.\n", crtc);
                 return -EAGAIN;
         }
@@ -633,24 +630,6 @@ int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, int crtc,
          */
         delta_ns = vpos * linedur_ns + hpos * pixeldur_ns;
 
-        /* Is vpos outside nominal vblank area, but less than
-         * 1/100 of a frame height away from start of vblank?
-         * If so, assume this isn't a massively delayed vblank
-         * interrupt, but a vblank interrupt that fired a few
-         * microseconds before true start of vblank. Compensate
-         * by adding a full frame duration to the final timestamp.
-         * Happens, e.g., on ATI R500, R600.
-         *
-         * We only do this if DRM_CALLED_FROM_VBLIRQ.
-         */
-        if ((flags & DRM_CALLED_FROM_VBLIRQ) && !invbl &&
-            ((vdisplay - vpos) < vtotal / 100)) {
-                delta_ns = delta_ns - framedur_ns;
-
-                /* Signal this correction as "applied". */
-                vbl_status |= 0x8;
-        }
-
         if (!drm_timestamp_monotonic)
                 etime = ktime_sub(etime, mono_time_offset);
 
diff --git a/drivers/gpu/drm/radeon/radeon_display.c b/drivers/gpu/drm/radeon/radeon_display.c
index 567215be4728..d680608f6f5b 100644
--- a/drivers/gpu/drm/radeon/radeon_display.c
+++ b/drivers/gpu/drm/radeon/radeon_display.c
@@ -1775,5 +1775,27 @@ int radeon_get_crtc_scanoutpos(struct drm_device *dev, int crtc, unsigned int fl
         if (in_vbl)
                 ret |= DRM_SCANOUTPOS_INVBL;
 
+        /* Is vpos outside nominal vblank area, but less than
+         * 1/100 of a frame height away from start of vblank?
+         * If so, assume this isn't a massively delayed vblank
+         * interrupt, but a vblank interrupt that fired a few
+         * microseconds before true start of vblank. Compensate
+         * by adding a full frame duration to the final timestamp.
+         * Happens, e.g., on ATI R500, R600.
+         *
+         * We only do this if DRM_CALLED_FROM_VBLIRQ.
+         */
+        if ((flags & DRM_CALLED_FROM_VBLIRQ) && !in_vbl) {
+                vbl_start = rdev->mode_info.crtcs[crtc]->base.hwmode.crtc_vdisplay;
+                vtotal = rdev->mode_info.crtcs[crtc]->base.hwmode.crtc_vtotal;
+
+                if (vbl_start - *vpos < vtotal / 100) {
+                        *vpos -= vtotal;
+
+                        /* Signal this correction as "applied". */
+                        ret |= 0x8;
+                }
+        }
+
         return ret;
 }