Re: [PATCH] tty: serial: samsung_tty: remove spinlock flags in interrupt handlers

[Andy Shevchenko]

On Tue, Mar 16, 2021 at 11:02 AM Johan Hovold <johan@xxxxxxxxxx> wrote:
>
> On Mon, Mar 15, 2021 at 07:12:12PM +0100, Krzysztof Kozlowski wrote:
> > Since interrupt handler is called with disabled local interrupts, there
> > is no need to use the spinlock primitives disabling interrupts as well.
>
> This isn't generally true due to "threadirqs" and that can lead to
> deadlocks if the console code is called from hard irq context.
>
> Now, this is *not* the case for this particular driver since it doesn't
> even bother to take the port lock in console_write(). That should
> probably be fixed instead.
>
> See https://lore.kernel.org/r/X7kviiRwuxvPxC8O@localhost.

Finn, Barry, something to check I think?

--
With Best Regards,
Andy Shevchenko