Re: Patch "USB: serial: ch341: fix resume after reset" has been added to the 4.4-stable tree

[Johan Hovold <johan@kernel.org>]

On Tue, Jan 17, 2017 at 02:04:41PM +0100, Greg Kroah-Hartman wrote:
> 
> This is a note to let you know that I've just added the patch titled
> 
>     USB: serial: ch341: fix resume after reset
> 
> to the 4.4-stable tree which can be found at:
>     http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
> 
> The filename of the patch is:
>      usb-serial-ch341-fix-resume-after-reset.patch
> and it can be found in the queue-4.4 subdirectory.
> 
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable@vger.kernel.org> know about it.
> 
> 
> From ce5e292828117d1b71cbd3edf9e9137cf31acd30 Mon Sep 17 00:00:00 2001
> From: Johan Hovold <johan@kernel.org>
> Date: Fri, 6 Jan 2017 19:15:14 +0100
> Subject: USB: serial: ch341: fix resume after reset
> 
> From: Johan Hovold <johan@kernel.org>
> 
> commit ce5e292828117d1b71cbd3edf9e9137cf31acd30 upstream.
> 
> Fix reset-resume handling which failed to resubmit the read and
> interrupt URBs, thereby leaving a port that was open before suspend in a
> broken state until closed and reopened.
> 
> Fixes: 1ded7ea47b88 ("USB: ch341 serial: fix port number changed after resume")
> Fixes: 2bfd1c96a9fb ("USB: serial: ch341: remove reset_resume callback")
> Signed-off-by: Johan Hovold <johan@kernel.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> 
> ---
>  drivers/usb/serial/ch341.c |   17 +++++++++++++----
>  1 file changed, 13 insertions(+), 4 deletions(-)
> 
> --- a/drivers/usb/serial/ch341.c
> +++ b/drivers/usb/serial/ch341.c
> @@ -538,14 +538,23 @@ static int ch341_tiocmget(struct tty_str
>  
>  static int ch341_reset_resume(struct usb_serial *serial)
>  {
> -	struct ch341_private *priv;
> -
> -	priv = usb_get_serial_port_data(serial->port[0]);
> +	struct usb_serial_port *port = serial->port[0];
> +	struct ch341_private *priv = usb_get_serial_port_data(port);
> +	int ret;
>  
>  	/* reconfigure ch341 serial port after bus-reset */
>  	ch341_configure(serial->dev, priv);
>  
> -	return 0;
> +	if (tty_port_initialized(&port->port)) {

Note that this needs to be

	if (test_bit(ASYNCB_INITIALIZED, &port->port.flags))

prior to commit d41861ca19c9 ("tty: Replace ASYNC_INITIALIZED bit and
update atomically") that went into 4.7.

I'll send a backport.

Johan