From: Richard Weinberger richard@nod.at
commit bc083a64b6c035135c0f80718f9e9192cc0867c6 upstream.
UML is a bit special since it does not have iomem nor dma. That means a lot of drivers will not build if they miss a dependency on HAS_IOMEM. s390 used to have the same issues but since it gained PCI support UML is the only stranger.
We are tired of patching dozens of new drivers after every merge window just to un-break allmod/yesconfig UML builds. One could argue that a decent driver has to know on what it depends and therefore a missing HAS_IOMEM dependency is a clear driver bug. But the dependency not obvious and not everyone does UML builds with COMPILE_TEST enabled when developing a device driver.
A possible solution to make these builds succeed on UML would be providing stub functions for ioremap() and friends which fail upon runtime. Another one is simply disabling COMPILE_TEST for UML. Since it is the least hassle and does not force use to fake iomem support let's do the latter.
Link: http://lkml.kernel.org/r/1466152995-28367-1-git-send-email-richard@nod.at Signed-off-by: Richard Weinberger richard@nod.at Acked-by: Arnd Bergmann arnd@arndb.de Cc: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Cc: Guenter Roeck linux@roeck-us.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- init/Kconfig | 1 + 1 file changed, 1 insertion(+)
--- a/init/Kconfig +++ b/init/Kconfig @@ -65,6 +65,7 @@ config CROSS_COMPILE
config COMPILE_TEST bool "Compile also drivers which will not load" + depends on !UML default n help Some drivers can be compiled on a different platform than they are