tty: serial: samsung: Fix console registration from module

On modern Exynos SoCs (like Exynos850) the UART can be implemented as a
part of USI IP-core. In such case, USI driver is used to initialize USI
registers, and it also calls of_platform_populate() to instantiate all
sub-nodes (e.g. serial node) of USI node. When serial driver is
built-in, but USI driver is a module, and CONFIG_SERIAL_SAMSUNG_CONSOLE
is enabled, next call chain will happen when loading USI module from
user space:

    usi_init
      v
    usi_probe
      v
    of_platform_populate
      v
    s3c24xx_serial_probe
      v
    uart_add_one_port
      v
    uart_configure_port
      v
    register_console
      v
    try_enable_new_console
      v
    s3c24xx_serial_console_setup

But because the serial driver is built-in, and
s3c24xx_serial_console_setup() is marked with __init keyword, that
symbol will discarded and long gone by that time already, causing failed
paging request.

That happens during the next config combination:

    EXYNOS_USI=m
    SERIAL_SAMSUNG=y
    SERIAL_SAMSUNG_CONSOLE=y

That config should be completely possible, so rather than limiting
SERIAL_SAMSUNG choice to "m" only when USI=m, remove __init keyword for
all affected functions.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20211204195757.8600-6-semen.protsenko@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sam Protsenko 2021-12-04 21:57:57 +02:00 committed by Greg Kroah-Hartman
parent 0882b473b0
commit 8cf8d3c4a6

View File

@ -2500,7 +2500,8 @@ s3c24xx_serial_console_write(struct console *co, const char *s,
uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
}
static void __init
/* Shouldn't be __init, as it can be instantiated from other module */
static void
s3c24xx_serial_get_options(struct uart_port *port, int *baud,
int *parity, int *bits)
{
@ -2563,7 +2564,8 @@ s3c24xx_serial_get_options(struct uart_port *port, int *baud,
}
}
static int __init
/* Shouldn't be __init, as it can be instantiated from other module */
static int
s3c24xx_serial_console_setup(struct console *co, char *options)
{
struct uart_port *port;