drm/radeon: update wait_for_vblank for r1xx-r4xx

Properly wait for the next vblank region.  The previous
code didn't always wait long enough depending on the timing.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

diff --git a/drivers/gpu/drm/radeon/r100.c b/drivers/gpu/drm/radeon/r100.c
index 9db5853..4973bff 100644 (file)
--- 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;
                }
        }
 }