Hi, This is version 2 of my attempt to get rid of a clang -Wnull-pointer-arithmetic warning for the use of PCI_IOBASE in asm-generic/io.h. This was originally found on s390 but should apply to all platforms leaving PCI_IOBASE undefined while making use of the inb() and friends helpers from asm-generic/io.h. Thanks, Niklas Changes since v1: - Added patch to explicitly set PCI_IOBASE to 0 on sparc as suggested by Arnd Bergmann - Instead of working around the warning with a uintptr_t PCI_IOBASE make inb() and friends explicitly WARN_ONCE() and return 0xff... (Arnd) Niklas Schnelle (2): sparc: explicitly set PCI_IOBASE to 0 asm-generic/io.h: Silence -Wnull-pointer-arithmetic warning on PCI_IOBASE arch/sparc/include/asm/io.h | 4 +++ include/asm-generic/io.h | 55 ++++++++++++++++++++++++++++++++++--- 2 files changed, 55 insertions(+), 4 deletions(-) -- 2.25.1