Re: [PATCH 1/1] tty: serial: samsung: add spin_lock for interrupt and console_write

Jiri Slaby
2022-04-06T13:12:50Z

On 06. 04. 22, 10:39, Jaewon Kim wrote:
> On 22. 4. 6. 17:21, Greg Kroah-Hartman wrote:
>> On Wed, Apr 06, 2022 at 05:22:16PM +0900, Jaewon Kim wrote:
>>> The console_write and IRQ handler can run concurrently.
>>> Problems may occurs console_write is continuously executed while the
>>> IRQ handler is running.
>>>
>>> Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
>>> ---
>>> drivers/tty/serial/samsung_tty.c | 12 ++++++++++++
>>> 1 file changed, 12 insertions(+)
>>>
>>> diff --git a/drivers/tty/serial/samsung_tty.c
>>> b/drivers/tty/serial/samsung_tty.c
>>> index e1585fbae909..9db479d728b5 100644
>>> --- a/drivers/tty/serial/samsung_tty.c
>>> +++ b/drivers/tty/serial/samsung_tty.c
>>> @@ -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 = 1;
>>
>> "1" is not a boolean :)
>
> return value of spin_trylock() is 1 or 0.
> It seems better to keep it as an int than to change it to bool.
> I will return it to int.

Hi, no, do not that. Simply use bool/true/false.

thanks,
--
js
suse labs