serial: stm32: Fix unused-variable warning

If CONFIG_SERIAL_EARLYCON and CONFIG_OF are both not set,
gcc warns about unused variable:

drivers/tty/serial/stm32-usart.c:83:32: error: ‘stm32h7_info’ defined but not used [-Werror=unused-variable]
 static struct stm32_usart_info stm32h7_info = {
                                ^~~~~~~~~~~~
drivers/tty/serial/stm32-usart.c:61:32: error: ‘stm32f7_info’ defined but not used [-Werror=unused-variable]
 static struct stm32_usart_info stm32f7_info = {
                                ^~~~~~~~~~~~
drivers/tty/serial/stm32-usart.c:40:32: error: ‘stm32f4_info’ defined but not used [-Werror=unused-variable]
 static struct stm32_usart_info stm32f4_info = {
                                ^~~~~~~~~~~~
cc1: all warnings being treated as errors

Mark these variables as __maybe_unused  to fix this.

Fixes: c7039ce904c0 ("serial: stm32: make info structs static to avoid sparse warnings")
Signed-off-by: Ren Zhijie <renzhijie2@huawei.com>
Link: https://lore.kernel.org/r/20220926025826.44145-1-renzhijie2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index c48f225eba8613ac982ac309c23ddce875c2771a..dfdbcf092facc2a5afe79194e4ab4ef2038da4e5 100644 (file)
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -37,7 +37,7 @@
 
 
 /* Register offsets */
-static struct stm32_usart_info stm32f4_info = {
+static struct stm32_usart_info __maybe_unused stm32f4_info = {
        .ofs = {
                .isr    = 0x00,
                .rdr    = 0x04,
@@ -58,7 +58,7 @@ static struct stm32_usart_info stm32f4_info = {
        }
 };
 
-static struct stm32_usart_info stm32f7_info = {
+static struct stm32_usart_info __maybe_unused stm32f7_info = {
        .ofs = {
                .cr1    = 0x00,
                .cr2    = 0x04,
@@ -80,7 +80,7 @@ static struct stm32_usart_info stm32f7_info = {
        }
 };
 
-static struct stm32_usart_info stm32h7_info = {
+static struct stm32_usart_info __maybe_unused stm32h7_info = {
        .ofs = {
                .cr1    = 0x00,
                .cr2    = 0x04,