[PATCH v2] serial: sifive: lock port in startup()/shutdown() callbacks

[Petr Mladek]

On Sat 2025-04-05 23:53:54, Ryo Takakura 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>
> Cc: stable at vger.kernel.org

I do not have the hardware around so I could not test it.
But the change make sense. It fixes a real race.
And the code looks reasonable:

Reviewed-by: Petr Mladek <pmladek at suse.com>

Best Regards,
Petr