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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: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
Link: https://lore.kernel.org/r/20220407071619.102249-2-jaewon02.kim@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jaewon Kim 2022-04-07 16:16:19 +09:00 committed by Greg Kroah-Hartman
parent ee157a79e7
commit e73b5c7f3d
1 changed files with 12 additions and 0 deletions
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12
drivers/tty/serial/samsung_tty.c
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@ -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 */