drm/radeon: update wait_for_vblank for evergreen+
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/evergreen.c b/drivers/gpu/drm/radeon/evergreen.c
index 124c193..f8a5b60 100644
--- a/drivers/gpu/drm/radeon/evergreen.c
+++ b/drivers/gpu/drm/radeon/evergreen.c
@@ -316,6 +316,27 @@
}
}
+static bool dce4_is_in_vblank(struct radeon_device *rdev, int crtc)
+{
+ if (RREG32(EVERGREEN_CRTC_STATUS + crtc_offsets[crtc]) & EVERGREEN_CRTC_V_BLANK)
+ return true;
+ else
+ return false;
+}
+
+static bool dce4_is_counter_moving(struct radeon_device *rdev, int crtc)
+{
+ u32 pos1, pos2;
+
+ pos1 = RREG32(EVERGREEN_CRTC_STATUS_POSITION + crtc_offsets[crtc]);
+ pos2 = RREG32(EVERGREEN_CRTC_STATUS_POSITION + crtc_offsets[crtc]);
+
+ if (pos1 != pos2)
+ return true;
+ else
+ return false;
+}
+
/**
* dce4_wait_for_vblank - vblank wait asic callback.
*
@@ -326,21 +347,28 @@
*/
void dce4_wait_for_vblank(struct radeon_device *rdev, int crtc)
{
- int i;
+ unsigned i = 0;
if (crtc >= rdev->num_crtc)
return;
- if (RREG32(EVERGREEN_CRTC_CONTROL + crtc_offsets[crtc]) & EVERGREEN_CRTC_MASTER_EN) {
- for (i = 0; i < rdev->usec_timeout; i++) {
- if (!(RREG32(EVERGREEN_CRTC_STATUS + crtc_offsets[crtc]) & EVERGREEN_CRTC_V_BLANK))
+ if (!(RREG32(EVERGREEN_CRTC_CONTROL + crtc_offsets[crtc]) & EVERGREEN_CRTC_MASTER_EN))
+ return;
+
+ /* depending on when we hit vblank, we may be close to active; if so,
+ * wait for another frame.
+ */
+ while (dce4_is_in_vblank(rdev, crtc)) {
+ if (i++ % 100 == 0) {
+ if (!dce4_is_counter_moving(rdev, crtc))
break;
- udelay(1);
}
- for (i = 0; i < rdev->usec_timeout; i++) {
- if (RREG32(EVERGREEN_CRTC_STATUS + crtc_offsets[crtc]) & EVERGREEN_CRTC_V_BLANK)
+ }
+
+ while (!dce4_is_in_vblank(rdev, crtc)) {
+ if (i++ % 100 == 0) {
+ if (!dce4_is_counter_moving(rdev, crtc))
break;
- udelay(1);
}
}
}