[PATCH] drm/radeon: update lockup tracking when scheduling in empty ring

[j.glisse at gmail.com]

From: Jerome Glisse <jglisse at redhat.com>

There might be issue with lockup detection when scheduling on an
empty ring that have been sitting idle for a while. Thus update
the lockup tracking data when scheduling new work in an empty ring.

Signed-off-by: Jerome Glisse <jglisse at redhat.com>
Tested-by: Andy Lutomirski <luto at amacapital.net>
Cc: stable at vger.kernel.org
---
 drivers/gpu/drm/radeon/radeon_ring.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/radeon/radeon_ring.c b/drivers/gpu/drm/radeon/radeon_ring.c
index e17faa7..82434018 100644
--- a/drivers/gpu/drm/radeon/radeon_ring.c
+++ b/drivers/gpu/drm/radeon/radeon_ring.c
@@ -402,6 +402,13 @@ int radeon_ring_alloc(struct radeon_device *rdev, struct radeon_ring *ring, unsi
 		return -ENOMEM;
 	/* Align requested size with padding so unlock_commit can
 	 * pad safely */
+	radeon_ring_free_size(rdev, ring);
+	if (ring->ring_free_dw == (ring->ring_size / 4)) {
+		/* This is an empty ring update lockup info to avoid
+		 * false positive.
+		 */
+		radeon_ring_lockup_update(ring);
+	}
 	ndw = (ndw + ring->align_mask) & ~ring->align_mask;
 	while (ndw > (ring->ring_free_dw - 1)) {
 		radeon_ring_free_size(rdev, ring);
-- 
1.7.11.7