[Intel-gfx] [PATCH] drm/i915: fix wait ioctl with negative timeout

[Chia-I Wu]

When timeout_ns is negative, it really means to wait indefinitely instead of
returning immediately.  But since userspace can no longer rely on that, I am
not sure if there is any point fixing it.

Signed-off-by: Chia-I Wu <olvaffe at gmail.com>
---
 drivers/gpu/drm/i915/i915_gem.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index ad55b06..3da2d62 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2787,9 +2787,9 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 		 goto out;
 
 	/* Do this after OLR check to make sure we make forward progress polling
-	 * on this IOCTL with a timeout <=0 (like busy ioctl)
+	 * on this IOCTL with a timeout == 0 (like busy ioctl)
 	 */
-	if (args->timeout_ns <= 0) {
+	if (args->timeout_ns == 0) {
 		ret = -ETIME;
 		goto out;
 	}
@@ -2798,7 +2798,8 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	reset_counter = atomic_read(&dev_priv->gpu_error.reset_counter);
 	mutex_unlock(&dev->struct_mutex);
 
-	return __wait_seqno(ring, seqno, reset_counter, true, &args->timeout_ns,
+	return __wait_seqno(ring, seqno, reset_counter, true,
+			    (args->timeout_ns > 0) ? &args->timeout_ns : NULL,
 			    file->driver_priv);
 
 out:
-- 
2.1.1