[jcmvbkbc-xtensa:xtensa-6.0-esp32 7/12] drivers/tty/serial/esp32_uart.c:33:6: warning: no previous prototype for function 'dbg_echo'

From: kernel test robot
Date: Wed Sep 21 2022 - 11:30:15 EST


tree: https://github.com/jcmvbkbc/linux-xtensa xtensa-6.0-esp32
head: 513fb5af258c5311c5e0684c21db9aeb48e981e8
commit: a17e7b31fc865c922149feb5c560bc4c497b8c34 [7/12] WIP: drivers/tty/serial: add driver for ESP32 UART
config: riscv-randconfig-r032-20220921 (https://download.01.org/0day-ci/archive/20220921/202209212350.zedDtGpw-lkp@xxxxxxxxx/config)
compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project 791a7ae1ba3efd6bca96338e10ffde557ba83920)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# install riscv cross compiling tool for clang build
# apt-get install binutils-riscv64-linux-gnu
# https://github.com/jcmvbkbc/linux-xtensa/commit/a17e7b31fc865c922149feb5c560bc4c497b8c34
git remote add jcmvbkbc-xtensa https://github.com/jcmvbkbc/linux-xtensa
git fetch --no-tags jcmvbkbc-xtensa xtensa-6.0-esp32
git checkout a17e7b31fc865c922149feb5c560bc4c497b8c34
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/clk/ drivers/misc/ drivers/net/wireless/ralink/rt2x00/ drivers/pinctrl/ drivers/tty/serial/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>

All warnings (new ones prefixed by >>):

>> drivers/tty/serial/esp32_uart.c:33:6: warning: no previous prototype for function 'dbg_echo' [-Wmissing-prototypes]
void dbg_echo(const char *s)
^
drivers/tty/serial/esp32_uart.c:33:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void dbg_echo(const char *s)
^
static
>> drivers/tty/serial/esp32_uart.c:48:6: warning: no previous prototype for function 'dbg_printf' [-Wmissing-prototypes]
void dbg_printf(const char *fmt, ...)
^
drivers/tty/serial/esp32_uart.c:48:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
void dbg_printf(const char *fmt, ...)
^
static
2 warnings generated.


vim +/dbg_echo +33 drivers/tty/serial/esp32_uart.c

32
> 33 void dbg_echo(const char *s)
34 {
35 volatile void __iomem *base = (volatile void __iomem *)0x3ff40000;
36
37 while ((readl(base + UART_STATUS_REG) & UART_TXFIFO_CNT_MASK) != 0)
38 ;
39
40 while (*s) {
41 if (*s == '\n')
42 writel('\r', base + UART_FIFO_REG);
43 writel(*s, base + UART_FIFO_REG);
44 ++s;
45 }
46 }
47
> 48 void dbg_printf(const char *fmt, ...)
49 {
50 va_list ap;
51 char buf[256];
52
53 va_start(ap, fmt);
54 vsnprintf(buf, sizeof(buf), fmt, ap);
55 va_end(ap);
56 dbg_echo(buf);
57 }
58

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