Hi Alan, Kernel build failed on tree: git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-next head: 40c9f61eae9098212b6906f29f30f08f7a19b5e2 commit: 2655a2c76f80d91da34faa8f4e114d1793435ed3 [6/9] 8250: use the 8250 register interface not the legacy one config: i386-randconfig-usb2 (attached as .config) All related error/warning messages: drivers/tty/serial/8250/8250_dw.c: In function 'dw8250_probe': drivers/tty/serial/8250/8250_dw.c:92:9: error: variable 'uart' has initializer but incomplete type drivers/tty/serial/8250/8250_dw.c:92:24: error: storage size of 'uart' isn't known drivers/tty/serial/8250/8250_dw.c:92:24: warning: unused variable 'uart' [-Wunused-variable] drivers/tty/serial/of_serial.c:147:3: error: implicit declaration of function 'serial8250_register_port' [-Werror=implicit-function-declaration] drivers/char/mwave/mwavedd.c:472:2: error: implicit declaration of function 'serial8250_register_port' [-Werror=implicit-function-declaration] vim +92 drivers/tty/serial/8250/8250_dw.c 89 90 static int __devinit dw8250_probe(struct platform_device *pdev) 91 { > 92 struct uart_8250_port uart = {}; 93 struct resource *regs = platform_get_resource(pdev, IORESOURCE_MEM, 0); 94 struct resource *irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); 95 struct device_node *np = pdev->dev.of_node; --- 0-DAY kernel build testing backend Open Source Technology Centre Fengguang Wu Intel Corporation