In certain randconfigs, clang warns:
drivers/gpu/drm/exynos/exynos_drm_dma.c:121:19: warning: variable 'mapping' is uninitialized when used here [-Wuninitialized] priv->mapping = mapping; ^~~~~~~ drivers/gpu/drm/exynos/exynos_drm_dma.c:111:16: note: initialize the variable 'mapping' to silence this warning void *mapping; ^ = NULL 1 warning generated.
This occurs when CONFIG_EXYNOS_IOMMU is enabled and both CONFIG_ARM_DMA_USE_IOMMU and CONFIG_IOMMU_DMA are disabled, which makes the code look like
void *mapping;
if (0) mapping = arm_iommu_create_mapping() else if (0) mapping = iommu_get_domain_for_dev()
... priv->mapping = mapping;
Add an else branch that initializes mapping to the -ENODEV error pointer so that there is no more warning and the driver does not change during runtime.
Reported-by: kernel test robot lkp@intel.com Signed-off-by: Nathan Chancellor nathan@kernel.org --- drivers/gpu/drm/exynos/exynos_drm_dma.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dma.c b/drivers/gpu/drm/exynos/exynos_drm_dma.c index 0644936afee2..bf33c3084cb4 100644 --- a/drivers/gpu/drm/exynos/exynos_drm_dma.c +++ b/drivers/gpu/drm/exynos/exynos_drm_dma.c @@ -115,6 +115,8 @@ int exynos_drm_register_dma(struct drm_device *drm, struct device *dev, EXYNOS_DEV_ADDR_START, EXYNOS_DEV_ADDR_SIZE); else if (IS_ENABLED(CONFIG_IOMMU_DMA)) mapping = iommu_get_domain_for_dev(priv->dma_dev); + else + mapping = ERR_PTR(-ENODEV);
if (IS_ERR(mapping)) return PTR_ERR(mapping);
base-commit: 7d549995d4e0d99b68e8a7793a0d23da6fc40fe8