Commit e73b5c7f authored by Jaewon Kim's avatar Jaewon Kim Committed by Greg Kroah-Hartman
Browse files

tty: serial: samsung: add spin_lock for interrupt and console_write 



The console_write and IRQ handler can run concurrently.
Problems may occurs console_write is continuously executed while
the IRQ handler is running.

Reviewed-by: default avatarJiri Slaby <jirislaby@kernel.org>
Signed-off-by: default avatarJaewon Kim <jaewon02.kim@samsung.com>
Link: https://lore.kernel.org/r/20220407071619.102249-2-jaewon02.kim@samsung.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ee157a79

drivers/tty/serial/samsung_tty.c

+12 −0
Original line number Diff line number Diff line
@@ -2480,12 +2480,24 @@ s3c24xx_serial_console_write(struct console *co, const char *s, 
			     unsigned int count)

{

	unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);

	unsigned long flags;

	bool locked = true;



	/* not possible to xmit on unconfigured port */

	if (!s3c24xx_port_configured(ucon))

		return;



	if (cons_uart->sysrq)

		locked = false;

	else if (oops_in_progress)

		locked = spin_trylock_irqsave(&cons_uart->lock, flags);

	else

		spin_lock_irqsave(&cons_uart->lock, flags);



	uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);



	if (locked)

		spin_unlock_irqrestore(&cons_uart->lock, flags);

}



/* Shouldn't be __init, as it can be instantiated from other module */