commit 8fd524b355da ("x86: Kill bad_dma_address variable") has killed
bad_dma_address variable and used instead of macro DMA_ERROR_CODE
which is always zero. Since dma_addr is unsigned, the statement
dma_addr >= DMA_ERROR_CODE
is always true, and not needed.
arch/x86/kernel/pci-calgary_64.c: In function ‘iommu_free’:
arch/x86/kernel/pci-calgary_64.c:299:2: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
if (unlikely((dma_addr >= DMA_ERROR_CODE) && (dma_addr < badend))) {