[Intel-gfx] [PATCH 2/2] tests/gem_eio: Resilience against "hanging too fast"

[Daniel Vetter]

Since $debugfs/i915_wedged restores a wedged gpu by using a normal gpu
hang we need to be careful to not run into the "hanging too fast
check":

- don't restore the ban period, but instead keep it at 0.
- make sure we idle the gpu fully before hanging it again (wait
  subtest missted that).

With this gem_eio works now reliable even when I don't run the
subtests individually.

Of course it's a bit fishy that the default ctx gets blamed for
essentially doing nothing, but until that's figured out in upstream
it's better to make the test work for now.

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
 tests/gem_eio.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tests/gem_eio.c b/tests/gem_eio.c
index 8345d1a7a429..6c07d9175b95 100644
--- a/tests/gem_eio.c
+++ b/tests/gem_eio.c
@@ -84,13 +84,17 @@ static void trigger_reset(int fd)
 
 static void wedge_gpu(int fd)
 {
+	igt_hang_ring_t hang;
+
 	/* First idle the GPU then disable GPU resets before injecting a hang */
 	gem_quiescent_gpu(fd);
 
 	igt_require(i915_reset_control(false));
 
 	igt_debug("Wedging GPU by injecting hang\n");
-	igt_post_hang_ring(fd, igt_hang_ring(fd, I915_EXEC_DEFAULT));
+	hang = igt_hang_ring(fd, I915_EXEC_DEFAULT);
+	hang.ban = 0;
+	igt_post_hang_ring(fd, hang);
 
 	igt_assert(i915_reset_control(true));
 }
@@ -161,10 +165,14 @@ static void test_wait(int fd)
 {
 	igt_hang_ring_t hang;
 
+	/* First idle the GPU then disable GPU resets before injecting a hang */
+	gem_quiescent_gpu(fd);
+
 	igt_require(i915_reset_control(false));
 
 	hang = igt_hang_ring(fd, I915_EXEC_DEFAULT);
 	igt_assert_eq(__gem_wait(fd, hang.handle, -1), 0);
+	hang.ban = 0;
 	igt_post_hang_ring(fd, hang);
 
 	igt_assert(i915_reset_control(true));
-- 
2.1.0