Re: [PATCH] tty/serial/imx: Enable TXEN bit in imx_poll_init().

From: Greg KH
Date: Tue Dec 01 2020 - 05:10:55 EST


On Tue, Dec 01, 2020 at 09:52:49AM +0800, jiladahe1997 wrote:
> From: Mingrui Ren <972931182@xxxxxx>
>
> As described in Documentation, poll_init() is called by kgdb to initialize
> hardware which support both poll_put_char() and poll_get_char().
>
> It's necessary to enable TXEN bit, otherwise, it will cause hardware fault
> and kernel panic when calling imx_poll_put_char().
>
> Generally, if use /dev/ttymxc0 as kgdb console as well as system
> console, ttymxc0 is initialized early by system console which does enable TXEN
> bit.But when use /dev/ttymxc1 as kgbd console, ttymxc1 is only initialized by
> imx_poll_init() cannot enable the TXEN bit, which will cause kernel panic.
>
> Signed-off-by: Mingrui Ren <972931182@xxxxxx>
> ---
> drivers/tty/serial/imx.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)

You sent this twice? Which one is "correct"? I'll drop both from my
patch queue and wait for just one to be resent.

thanks,

greg k-h