igt/drv_missed_irq_hang: Increase busy load

The test relies on having to wait upon the GPU at some point and so
simulating a missed interrupt. If there is insufficient load on the GPU,
we can complete the task before we even wait.

References: https://bugs.freedesktop.org/show_bug.cgi?id=71334
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/tests/drv_missed_irq_hang b/tests/drv_missed_irq_hang
index 484e151..6e8cfc2 100755
--- a/tests/drv_missed_irq_hang
+++ b/tests/drv_missed_irq_hang
@@ -10,6 +10,12 @@
 
 cd $i915_dfs_path
 
+function blt_wait {
+	(cd $oldpath; $SOURCE_DIR/gem_exec_blt 16384) > /dev/null
+	(cd $oldpath; $SOURCE_DIR/gem_exec_blt 65536) > /dev/null
+	(cd $oldpath; $SOURCE_DIR/gem_exec_blt 262144) > /dev/null
+}
+
 function check_for_missed_irq {
 	if test `cat i915_ring_missed_irq` = 0x00000000; then
 		echo "missed interrupts undetected"
@@ -40,13 +46,11 @@
 	exit 3
 fi
 
-(cd $oldpath; $SOURCE_DIR/gem_exec_blt) > /dev/null
-
+blt_wait
 check_for_missed_irq
 check_for_hang
 
-(cd $oldpath; $SOURCE_DIR/gem_exec_blt) > /dev/null
-
+blt_wait
 check_for_hang
 
 echo 0 > i915_ring_test_irq
@@ -56,8 +60,7 @@
 	exit 3
 fi
 
-(cd $oldpath; $SOURCE_DIR/gem_exec_blt) > /dev/null
-
+blt_wait
 check_for_hang
 
 echo 0 > i915_ring_missed_irq