[Intel-gfx] [PATCH igt 1/9] lib: Always double check igt_require_hang_ring() on use

[Chris Wilson]

If we move the igt_require() into the hang injector, this makes simple
test cases even more convenient. More complex test cases can always do
their own precursory check before settting up the test.

However, this does embed the assumption that the first context we are
called from is safe (i.e no i915.enable_hangcheck/i915.reset
interferrence).

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 lib/igt_gt.c | 29 ++++++++++++++++++-----------
 1 file changed, 18 insertions(+), 11 deletions(-)

diff --git a/lib/igt_gt.c b/lib/igt_gt.c
index 688ea5e..3d618d6 100644
--- a/lib/igt_gt.c
+++ b/lib/igt_gt.c
@@ -50,17 +50,21 @@
 
 static bool has_gpu_reset(int fd)
 {
-	struct drm_i915_getparam gp;
-	int val = 0;
-
-	memset(&gp, 0, sizeof(gp));
-	gp.param = 35; /* HAS_GPU_RESET */
-	gp.value = &val;
-
-	if (ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp))
-		return intel_gen(intel_get_drm_devid(fd)) >= 5;
-
-	return val > 0;
+	static int once = -1;
+	if (once < 0) {
+		struct drm_i915_getparam gp;
+		int val = 0;
+
+		memset(&gp, 0, sizeof(gp));
+		gp.param = 35; /* HAS_GPU_RESET */
+		gp.value = &val;
+
+		if (ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp))
+			once = intel_gen(intel_get_drm_devid(fd)) >= 5;
+		else
+			once = val > 0;
+	}
+	return once;
 }
 
 /**
@@ -74,6 +78,7 @@ static bool has_gpu_reset(int fd)
  */
 void igt_require_hang_ring(int fd, int ring)
 {
+	gem_require_ring(fd, ring);
 	gem_context_require_ban_period(fd);
 	igt_require(has_gpu_reset(fd));
 }
@@ -100,6 +105,8 @@ igt_hang_ring_t igt_hang_ring(int fd, int ring)
 	unsigned ban;
 	unsigned len;
 
+	igt_require_hang_ring(fd, ring);
+
 	param.context = 0;
 	param.size = 0;
 	param.param = LOCAL_CONTEXT_PARAM_BAN_PERIOD;
-- 
2.6.3