drm/msm: return -EBUSY if bo still active

When we CPU_PREP a bo with NOSYNC flag (for example, to implement
PIPE_TRANSFER_DISCARD_WHOLE_RESOURCE), an -EBUSY return indicates to
userspace that the bo is still busy.  Previously it was incorrectly
returning 0 in this case.

And while we're in there throw in an bit of extra sanity checking in
case userspace tries to wait for a bogus fence.

Signed-off-by: Rob Clark <robdclark@gmail.com>

1 files changed, 33 insertions, 17 deletions

diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 864c9773636..008d772384c 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -499,25 +499,41 @@ int msm_wait_fence_interruptable(struct drm_device *dev, uint32_t fence,
 		struct timespec *timeout)
 {
 	struct msm_drm_private *priv = dev->dev_private;
-	unsigned long timeout_jiffies = timespec_to_jiffies(timeout);
-	unsigned long start_jiffies = jiffies;
-	unsigned long remaining_jiffies;
 	int ret;
 
-	if (time_after(start_jiffies, timeout_jiffies))
-		remaining_jiffies = 0;
-	else
-		remaining_jiffies = timeout_jiffies - start_jiffies;
-
-	ret = wait_event_interruptible_timeout(priv->fence_event,
-			priv->completed_fence >= fence,
-			remaining_jiffies);
-	if (ret == 0) {
-		DBG("timeout waiting for fence: %u (completed: %u)",
-				fence, priv->completed_fence);
-		ret = -ETIMEDOUT;
-	} else if (ret != -ERESTARTSYS) {
-		ret = 0;
+	if (!priv->gpu)
+		return 0;
+
+	if (fence > priv->gpu->submitted_fence) {
+		DRM_ERROR("waiting on invalid fence: %u (of %u)\n",
+				fence, priv->gpu->submitted_fence);
+		return -EINVAL;
+	}
+
+	if (!timeout) {
+		/* no-wait: */
+		ret = fence_completed(dev, fence) ? 0 : -EBUSY;
+	} else {
+		unsigned long timeout_jiffies = timespec_to_jiffies(timeout);
+		unsigned long start_jiffies = jiffies;
+		unsigned long remaining_jiffies;
+
+		if (time_after(start_jiffies, timeout_jiffies))
+			remaining_jiffies = 0;
+		else
+			remaining_jiffies = timeout_jiffies - start_jiffies;
+
+		ret = wait_event_interruptible_timeout(priv->fence_event,
+				fence_completed(dev, fence),
+				remaining_jiffies);
+
+		if (ret == 0) {
+			DBG("timeout waiting for fence: %u (completed: %u)",
+					fence, priv->completed_fence);
+			ret = -ETIMEDOUT;
+		} else if (ret != -ERESTARTSYS) {
+			ret = 0;
+		}
 	}
 
 	return ret;