lib: extract igt_open_forcewake_handle

... and I immediately regret that I've killed the return value
for igt_debugfs_init, since we have callers which need to work
without the forcewake stuff, e.g. the reg dumper needs to work
without i915 loaded.

Put this new helper to good use in the mmio code and the pm_pc8
testcase.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

1 files changed, 3 insertions, 2 deletions

diff --git a/tests/pm_pc8.c b/tests/pm_pc8.c
index 5c74b234..c672e809 100644
--- a/tests/pm_pc8.c
+++ b/tests/pm_pc8.c
@@ -46,6 +46,7 @@
 #include "intel_gpu_tools.h"
 #include "i915_drm.h"
 #include "igt_kms.h"
+#include "igt_debugfs.h"
 
 #define MSR_PC8_RES	0x630
 #define MSR_PC9_RES	0x631
@@ -1009,8 +1010,8 @@ static void debugfs_forcewake_user_subtest(void)
 	disable_all_screens(&ms_data);
 	igt_assert(wait_for_suspended());
 
-	fd = open("/sys/kernel/debug/dri/0/i915_forcewake_user", O_RDONLY);
-	igt_require(fd);
+	fd = igt_open_forcewake_handle();
+	igt_require(fd >= 0);
 
 	if (has_runtime_pm) {
 		igt_assert(wait_for_active());