drm: suppress intentional warning backtraces in scaling unit tests

The drm_test_rect_calc_hscale and drm_test_rect_calc_vscale unit tests
intentionally trigger warning backtraces by providing bad parameters to
the tested functions.  What is tested is the return value, not the
existence of a warning backtrace.  Suppress the backtraces to avoid
clogging the kernel log and distraction from real problems.

Link: https://lkml.kernel.org/r/20250313114329.284104-6-acarmina@redhat.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Alessandro Carminati <acarmina@redhat.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Acked-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Maíra Canal <mcanal@igalia.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Arthur Grillo <arthurgrillo@riseup.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Daniel Diaz <daniel.diaz@linaro.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Gow <davidgow@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naresh Kamboju <naresh.kamboju@linaro.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Rae Moar <rmoar@google.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Simon Horman <horms@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Ville Syrjala <ville.syrjala@linux.intel.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/gpu/drm/tests/drm_rect_test.c b/drivers/gpu/drm/tests/drm_rect_test.c
index 17e1f34b761017ce6c9576bd04dde3e55a40af0c..e8d707b4a1016350c0c91141b1767bcac9e2d869 100644 (file)
--- a/drivers/gpu/drm/tests/drm_rect_test.c
+++ b/drivers/gpu/drm/tests/drm_rect_test.c
@@ -406,22 +406,38 @@ KUNIT_ARRAY_PARAM(drm_rect_scale, drm_rect_scale_cases, drm_rect_scale_case_desc
 
 static void drm_test_rect_calc_hscale(struct kunit *test)
 {
+       DEFINE_SUPPRESSED_WARNING(drm_calc_scale);
        const struct drm_rect_scale_case *params = test->param_value;
        int scaling_factor;
 
+       /*
+        * drm_rect_calc_hscale() generates a warning backtrace whenever bad
+        * parameters are passed to it. This affects all unit tests with an
+        * error code in expected_scaling_factor.
+        */
+       KUNIT_START_SUPPRESSED_WARNING(drm_calc_scale);
        scaling_factor = drm_rect_calc_hscale(&params->src, &params->dst,
                                              params->min_range, params->max_range);
+       KUNIT_END_SUPPRESSED_WARNING(drm_calc_scale);
 
        KUNIT_EXPECT_EQ(test, scaling_factor, params->expected_scaling_factor);
 }
 
 static void drm_test_rect_calc_vscale(struct kunit *test)
 {
+       DEFINE_SUPPRESSED_WARNING(drm_calc_scale);
        const struct drm_rect_scale_case *params = test->param_value;
        int scaling_factor;
 
+       /*
+        * drm_rect_calc_vscale() generates a warning backtrace whenever bad
+        * parameters are passed to it. This affects all unit tests with an
+        * error code in expected_scaling_factor.
+        */
+       KUNIT_START_SUPPRESSED_WARNING(drm_calc_scale);
        scaling_factor = drm_rect_calc_vscale(&params->src, &params->dst,
                                              params->min_range, params->max_range);
+       KUNIT_END_SUPPRESSED_WARNING(drm_calc_scale);
 
        KUNIT_EXPECT_EQ(test, scaling_factor, params->expected_scaling_factor);
 }