From: Arnd Bergmann <arnd@xxxxxxxx> [ Upstream commit f13efafc1a2cf30d4a74c00f40210d6de36db2d0 ] clang-14 notices that a comparison is never true when CONFIG_PHYS_ADDR_T_64BIT is disabled: drivers/iommu/mtk_iommu.c:553:34: error: result of comparison of constant 5368709120 with expression of type 'phys_addr_t' (aka 'unsigned int') is always false [-Werror,-Wtautological-constant-out-of-range-compare] if (dom->data->enable_4GB && pa >= MTK_IOMMU_4GB_MODE_REMAP_BASE) ~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Add an explicit check for the type of the variable to skip the check and the warning in that case. Fixes: b4dad40e4f35 ("iommu/mediatek: Adjust the PA for the 4GB Mode") Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Reviewed-by: Yong Wu <yong.wu@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210927121857.941160-1-arnd@xxxxxxxxxx Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/iommu/mtk_iommu.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 6f7c69688ce2a..366a9c05642fa 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -561,7 +561,9 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain, phys_addr_t pa; pa = dom->iop->iova_to_phys(dom->iop, iova); - if (dom->data->enable_4GB && pa >= MTK_IOMMU_4GB_MODE_REMAP_BASE) + if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT) && + dom->data->enable_4GB && + pa >= MTK_IOMMU_4GB_MODE_REMAP_BASE) pa &= ~BIT_ULL(32); return pa; -- 2.33.0