[PATCH printk v5 1/1] printk: extend console_lock for per-console locking

[Petr Mladek]

On Fri 2022-05-06 08:43:02, Marek Szyprowski wrote:
> Hi John,
> 
> On 06.05.2022 00:33, John Ogness wrote:
> > On 2022-05-05, John Ogness <john.ogness at linutronix.de> wrote:
> >> I will go through and check if all access to AML_UART_CONTROL is
> >> protected by port->lock.
> > The startup() callback of the uart_ops is not called with the port
> > locked. I'm having difficulties identifying if the startup() callback
> > can occur after the console was already registered via meson_uart_init()
> > and could be actively printing, but I see other serial drivers are
> > protecting their registers in the startup() callback with the
> > port->lock.

I guess that it is used by the early console before the racy
code is called.

> > Could you try booting the meson hardware with the following change? (And
> > removing any previous debug changes I posted?)
> 
> Bingo! It looks that the startup() is called when getty initializes 
> console. This fixed the issues observed on the Amlogic Meson based boards.
> 
> Feel free to add:
> 
> Tested-by: Marek Szyprowski <m.szyprowski at samsung.com>

Uff, it is a huge relief that it has got fixed.

Best Regards,
Petr