At least the i915 and amd drivers enable a bunch more compiler warnings than the kernel defaults.
Extend most of the W=1 warnings to the entire drm subsystem by default. Use the copy-pasted warnings from scripts/Makefile.extrawarn with s/KBUILD_CFLAGS/subdir-ccflags-y/ to make it easier to compare and keep up with them in the future. This is similar to the approach currently used in i915. Some of the -Wextra warnings do need to be disabled, just like in Makefile.extrawarn, but take care to not disable them for W=2 or W=3 builds, depending on the warning. There are too many -Wformat-truncation warnings to cleanly fix up front; leave that warning disabled for now. v2: - Drop -Wformat-truncation (too many warnings) - Drop -Wstringop-overflow (enabled by default upstream) Cc: David Airlie <airl...@gmail.com> Cc: Daniel Vetter <dan...@ffwll.ch> Cc: Maarten Lankhorst <maarten.lankho...@linux.intel.com> Cc: Maxime Ripard <mrip...@kernel.org> Cc: Thomas Zimmermann <tzimmerm...@suse.de> Cc: Alex Deucher <alexander.deuc...@amd.com> Cc: Christian König <christian.koe...@amd.com> Cc: Pan, Xinhui <xinhui....@amd.com> Cc: Karol Herbst <kher...@redhat.com> Cc: Lyude Paul <ly...@redhat.com> Cc: Danilo Krummrich <d...@redhat.com> Cc: Rob Clark <robdcl...@gmail.com> Cc: Abhinav Kumar <quic_abhin...@quicinc.com> Cc: Dmitry Baryshkov <dmitry.barysh...@linaro.org> Cc: Sean Paul <s...@poorly.run> Cc: Marijn Suijten <marijn.suij...@somainline.org> Cc: Hamza Mahfooz <hamza.mahf...@amd.com> Acked-by: Javier Martinez Canillas <javi...@redhat.com> Acked-by: Thomas Zimmermann <tzimmerm...@suse.de> Acked-by: Sui Jingfeng <sui.jingf...@linux.dev> Signed-off-by: Jani Nikula <jani.nik...@intel.com> --- drivers/gpu/drm/Makefile | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile index 104b42df2e95..8b6be830f7c3 100644 --- a/drivers/gpu/drm/Makefile +++ b/drivers/gpu/drm/Makefile @@ -5,6 +5,33 @@ CFLAGS-$(CONFIG_DRM_USE_DYNAMIC_DEBUG) += -DDYNAMIC_DEBUG_MODULE +# Unconditionally enable W=1 warnings locally +# --- begin copy-paste W=1 warnings from scripts/Makefile.extrawarn +subdir-ccflags-y += -Wextra -Wunused -Wno-unused-parameter +subdir-ccflags-y += -Wmissing-declarations +subdir-ccflags-y += $(call cc-option, -Wrestrict) +subdir-ccflags-y += -Wmissing-format-attribute +subdir-ccflags-y += -Wmissing-prototypes +subdir-ccflags-y += -Wold-style-definition +subdir-ccflags-y += -Wmissing-include-dirs +subdir-ccflags-y += $(call cc-option, -Wunused-but-set-variable) +subdir-ccflags-y += $(call cc-option, -Wunused-const-variable) +subdir-ccflags-y += $(call cc-option, -Wpacked-not-aligned) +subdir-ccflags-y += $(call cc-option, -Wformat-overflow) +# FIXME: fix -Wformat-truncation warnings and uncomment +#subdir-ccflags-y += $(call cc-option, -Wformat-truncation) +subdir-ccflags-y += $(call cc-option, -Wstringop-truncation) +# The following turn off the warnings enabled by -Wextra +ifeq ($(findstring 2, $(KBUILD_EXTRA_WARN)),) +subdir-ccflags-y += -Wno-missing-field-initializers +subdir-ccflags-y += -Wno-type-limits +subdir-ccflags-y += -Wno-shift-negative-value +endif +ifeq ($(findstring 3, $(KBUILD_EXTRA_WARN)),) +subdir-ccflags-y += -Wno-sign-compare +endif +# --- end copy-paste + drm-y := \ drm_aperture.o \ drm_atomic.o \ -- 2.39.2