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

From: John Ogness
Date: Tue Apr 15 2025 - 03:42:44 EST


On 2025-04-12, Ryo Takakura <ryotkkr98@xxxxxxxxx> 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@xxxxxxxxx>
> Reviewed-by: Petr Mladek <pmladek@xxxxxxxx>

Reviewed-by: John Ogness <john.ogness@xxxxxxxxxxxxx>