Date:   Wed, 1 Mar 2023 09:39:45 +0100
From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     Lukasz Majczak <lma@semihalf.com>
Cc:     Jiri Slaby <jirislaby@kernel.org>,
        Guenter Roeck <groeck@chromium.org>,
        linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
        upstream@semihalf.com, stable@vger.kernel.org
Subject: Re: [PATCH] serial: core: fix broken console after suspend
Message-ID: <Y/8PUdEwskXuWZHA@kroah.com>
References: <20230301075751.43839-1-lma@semihalf.com>
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On Wed, Mar 01, 2023 at 08:57:51AM +0100, Lukasz Majczak wrote:
> Re-enable the console device after suspending, causes its cflags,
> ispeed and ospeed to be set anew, basing on the values stored in
> uport->cons. The issue is that these values are set only once,
> when parsing console parameters after boot (see uart_set_options()),
> next after configuring a port in uart_port_startup() these parameteres
> (cflags, ispeed and ospeed) are copied to termios structure and
> the orginal one (stored in uport->cons) are cleared, but there is no place
> in code where those fields are checked against 0.
> When kernel calls uart_resume_port() and setups console, it copies cflags,
> ispeed and ospeed values from uart->cons,but those are alread cleared.
> The efect is that console is broken.
> This patch address this by preserving the cflags, ispeed and
> ospeed fields in uart->cons during uart_port_startup().
> 
> Signed-off-by: Lukasz Majczak <lma@semihalf.com>
> Cc: stable@vger.kernel.org
> ---
>  drivers/tty/serial/serial_core.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 2bd32c8ece39..394a05c09d87 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -225,9 +225,6 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
>  			tty->termios.c_cflag = uport->cons->cflag;
>  			tty->termios.c_ispeed = uport->cons->ispeed;
>  			tty->termios.c_ospeed = uport->cons->ospeed;
> -			uport->cons->cflag = 0;
> -			uport->cons->ispeed = 0;
> -			uport->cons->ospeed = 0;
>  		}
>  		/*
>  		 * Initialise the hardware port settings.
> -- 
> 2.39.2.722.g9855ee24e9-goog
> 

What commit id does this fix?

thanks,

greg k-h