[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 <l...@intel.com>
Suggested-by: Nick Desaulniers <ndesaulni...@google.com>
Signed-off-by: Nathan Chancellor <nat...@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