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

[Neil Armstrong]

Hi,

On 06/05/2022 08:43, Marek Szyprowski wrote:
> Hi John,
>
> On 06.05.2022 00:33, John Ogness wrote:
> > On 2022-05-05, John Ogness <john.ogness@xxxxxxxxxxxxx> 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.
> >
> > 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@xxxxxxxxxxx>
>
> Best regards

Thanks all for figuring out the issue, perhaps other uart drivers could fall
in the same issue if startup code isn't protected with lock ?

Neil