[PATCH] drm/selftest: plane_helper: Put test structures in static storage

[Nathan Chancellor]

Clang warns on certain 32-bit architectures:

  drivers/gpu/drm/selftests/test-drm_plane_helper.c:76:5: warning: stack frame size (1064) exceeds limit (1024) in 'igt_check_plane_state' [-Wframe-larger-than]
  int igt_check_plane_state(void *ignored)
      ^
  1 warning generated.

The structures in igt_check_plane_state() total 1008 bytes, so any small
amount of inlining will cause the stack frame to exceed the 32-bit limit
of 1024, triggering the warning.

Move these structures to static storage, which dramatically reduces the
amount of stack space in igt_check_plane_state(). There is no testing
impact, as igt_check_plane_state() is only called once in the driver.

Fixes: 943e6a8beeac ("mock a drm_plane in igt_check_plane_state to make the test more robust")
Link: https://github.com/ClangBuiltLinux/linux/issues/1600
Reported-by: kernel test robot <lkp at intel.com>
Suggested-by: Nick Desaulniers <ndesaulniers at google.com>
Signed-off-by: Nathan Chancellor <nathan at kernel.org>
---
 drivers/gpu/drm/selftests/test-drm_plane_helper.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/selftests/test-drm_plane_helper.c b/drivers/gpu/drm/selftests/test-drm_plane_helper.c
index ceebeede55ea..b61273e9c403 100644
--- a/drivers/gpu/drm/selftests/test-drm_plane_helper.c
+++ b/drivers/gpu/drm/selftests/test-drm_plane_helper.c
@@ -77,7 +77,7 @@ int igt_check_plane_state(void *ignored)
 {
 	int ret;
 
-	const struct drm_crtc_state crtc_state = {
+	static const struct drm_crtc_state crtc_state = {
 		.crtc = ZERO_SIZE_PTR,
 		.enable = true,
 		.active = true,
@@ -87,14 +87,14 @@ int igt_check_plane_state(void *ignored)
 				DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC)
 		},
 	};
-	struct drm_plane plane = {
+	static struct drm_plane plane = {
 		.dev = NULL
 	};
-	struct drm_framebuffer fb = {
+	static struct drm_framebuffer fb = {
 		.width = 2048,
 		.height = 2048
 	};
-	struct drm_plane_state plane_state = {
+	static struct drm_plane_state plane_state = {
 		.plane = &plane,
 		.crtc = ZERO_SIZE_PTR,
 		.fb = &fb,

base-commit: 9ae2ac4d31a85ce59cc560d514a31b95f4ace154
-- 
2.35.1