[PATCH v3] serial: sifive: lock port in startup()/shutdown() callbacks

[John Ogness]

On 2025-04-12, Ryo Takakura <ryotkkr98 at gmail.com> wrote:
> startup()/shutdown() callbacks access SIFIVE_SERIAL_IE_OFFS.
> The register is also accessed from write() callback.
>
> If console were printing and startup()/shutdown() callback
> gets called, its access to the register could be overwritten.
>
> Add port->lock to startup()/shutdown() callbacks to make sure
> their access to SIFIVE_SERIAL_IE_OFFS is synchronized against
> write() callback.
>
> Fixes: 45c054d0815b ("tty: serial: add driver for the SiFive UART")
> Signed-off-by: Ryo Takakura <ryotkkr98 at gmail.com>
> Reviewed-by: Petr Mladek <pmladek at suse.com>

Reviewed-by: John Ogness <john.ogness at linutronix.de>