Hi Linus, It's probably a bug fix that unveils the link errors. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: f51fdffad5b7709d0ade40736b58a2da2707fa15 commit: 2527ecc9195e9c66252af24c4689e8a67cd4ccb9 gpio: Fix OF build problem on UM date: 6 weeks ago config: um-allmodconfig (attached as .config) compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901 reproduce: git checkout 2527ecc9195e9c66252af24c4689e8a67cd4ccb9 # save the attached .config to linux build tree make ARCH=um All errors (new ones prefixed by >>): arch/um/drivers/built-in.o: In function `vde_open_real': (.text+0xc7d1): warning: Using 'getgrnam' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking arch/um/drivers/built-in.o: In function `vde_open_real': (.text+0xc61c): warning: Using 'getpwuid' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking arch/um/drivers/built-in.o: In function `vde_open_real': (.text+0xc935): warning: Using 'getaddrinfo' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking arch/um/drivers/built-in.o: In function `pcap_nametoaddr': (.text+0x1d3c5): warning: Using 'gethostbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking arch/um/drivers/built-in.o: In function `pcap_nametonetaddr': (.text+0x1d465): warning: Using 'getnetbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking arch/um/drivers/built-in.o: In function `pcap_nametoproto': (.text+0x1d685): warning: Using 'getprotobyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking arch/um/drivers/built-in.o: In function `pcap_nametoport': (.text+0x1d4b7): warning: Using 'getservbyname' in statically linked applications requires at runtime the shared libraries from the glibc version used for linking drivers/built-in.o: In function `fwnode_get_named_gpiod': >> drivers/gpio/gpiolib.c:3215: undefined reference to `of_get_named_gpiod_flags' drivers/built-in.o: In function `gpiod_get_index': drivers/gpio/gpiolib.c:3140: undefined reference to `of_get_named_gpiod_flags' drivers/built-in.o: In function `zx_gpio_probe': >> drivers/gpio/gpio-zx.c:229: undefined reference to `devm_ioremap_resource' `.text.exit' referenced in section `.fini_array' of /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/libc.a(sdlerror.o): defined in discarded section `.text.exit' of /usr/lib/gcc/x86_64-linux-gnu/6/../../../x86_64-linux-gnu/libc.a(sdlerror.o) >> collect2: error: ld returned 1 exit status vim +3215 drivers/gpio/gpiolib.c 40b731831 Mika Westerberg 2014-10-21 3199 * In case of error an ERR_PTR() is returned. 40b731831 Mika Westerberg 2014-10-21 3200 */ 40b731831 Mika Westerberg 2014-10-21 3201 struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode, 40b731831 Mika Westerberg 2014-10-21 3202 const char *propname) 40b731831 Mika Westerberg 2014-10-21 3203 { 40b731831 Mika Westerberg 2014-10-21 3204 struct gpio_desc *desc = ERR_PTR(-ENODEV); 40b731831 Mika Westerberg 2014-10-21 3205 bool active_low = false; 90b665f62 Laurent Pinchart 2015-10-13 3206 bool single_ended = false; 40b731831 Mika Westerberg 2014-10-21 3207 int ret; 40b731831 Mika Westerberg 2014-10-21 3208 40b731831 Mika Westerberg 2014-10-21 3209 if (!fwnode) 40b731831 Mika Westerberg 2014-10-21 3210 return ERR_PTR(-EINVAL); 40b731831 Mika Westerberg 2014-10-21 3211 40b731831 Mika Westerberg 2014-10-21 3212 if (is_of_node(fwnode)) { 40b731831 Mika Westerberg 2014-10-21 3213 enum of_gpio_flags flags; 40b731831 Mika Westerberg 2014-10-21 3214 c181fb3e7 Alexander Sverdlin 2015-06-22 @3215 desc = of_get_named_gpiod_flags(to_of_node(fwnode), propname, 0, 40b731831 Mika Westerberg 2014-10-21 3216 &flags); 90b665f62 Laurent Pinchart 2015-10-13 3217 if (!IS_ERR(desc)) { 40b731831 Mika Westerberg 2014-10-21 3218 active_low = flags & OF_GPIO_ACTIVE_LOW; 90b665f62 Laurent Pinchart 2015-10-13 3219 single_ended = flags & OF_GPIO_SINGLE_ENDED; 90b665f62 Laurent Pinchart 2015-10-13 3220 } 40b731831 Mika Westerberg 2014-10-21 3221 } else if (is_acpi_node(fwnode)) { 40b731831 Mika Westerberg 2014-10-21 3222 struct acpi_gpio_info info; 40b731831 Mika Westerberg 2014-10-21 3223 :::::: The code at line 3215 was first introduced by commit :::::: c181fb3e723351e2f7a1f76b6c0627a4b8ad1723 ACPI / OF: Rename of_node() and acpi_node() to to_of_node() and to_acpi_node() :::::: TO: Alexander Sverdlin :::::: CC: Rafael J. Wysocki --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation