Re: [PATCH V8 07/10] USB: f81232: implement set_termios()

From: Johan Hovold <johan@kernel.org>
To: Peter Hung <hpeter@gmail.com>
Cc: johan@kernel.org, gregkh@linuxfoundation.org,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org,
	tom_tsai@fintek.com.tw, peter_hong@fintek.com.tw,
	Peter Hung <hpeter+linux_kernel@gmail.com>
Subject: Re: [PATCH V8 07/10] USB: f81232: implement set_termios()
Date: Sat, 14 Mar 2015 13:24:01 +0100	[thread overview]
Message-ID: <20150314122401.GF9442@localhost> (raw)
In-Reply-To: <1424944936-7117-8-git-send-email-hpeter+linux_kernel@gmail.com>

On Thu, Feb 26, 2015 at 06:02:13PM +0800, Peter Hung wrote:

> f81232_set_baudrate() is also changed from V7. Add error handling when LCR get
> failed or set LCR UART_LCR_DLAB failed. and older version, divisor is declared
> with u8, it's will make failed with baudrate lower than 600 (115200/300=384).
> We had changed divisor to int type.

No need to include this patch-revision changelog in the commit message.
You put it under the cut-off-line (---) below though.

> Signed-off-by: Peter Hung <hpeter+linux_kernel@gmail.com>
> ---
>  drivers/usb/serial/f81232.c | 112 ++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 108 insertions(+), 4 deletions(-)

>  static int f81232_port_enable(struct usb_serial_port *port)
>  {
>  	u8 val;
> @@ -391,15 +448,62 @@ static int f81232_port_disable(struct usb_serial_port *port)
>  static void f81232_set_termios(struct tty_struct *tty,
>  		struct usb_serial_port *port, struct ktermios *old_termios)
>  {
> -	/* FIXME - Stubbed out for now */
> +	u8 new_lcr = 0;
> +	int status = 0;
> +	speed_t baudrate;
>  
>  	/* Don't change anything if nothing has changed */
>  	if (old_termios && !tty_termios_hw_change(&tty->termios, old_termios))
>  		return;
>  
> -	/* Do the real work here... */
> -	if (old_termios)
> -		tty_termios_copy_hw(&tty->termios, old_termios);
> +	if (C_BAUD(tty) == B0)
> +		f81232_set_mctrl(port, 0, TIOCM_DTR | TIOCM_RTS);
> +	else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
> +		f81232_set_mctrl(port, TIOCM_DTR | TIOCM_RTS, 0);
> +
> +	baudrate = tty_get_baud_rate(tty);
> +	if (baudrate > 0) {
> +		if (baudrate > F81232_MAX_BAUDRATE)
> +			baudrate = F81232_MAX_BAUDRATE;
> +
> +		tty_encode_baud_rate(tty, baudrate, baudrate);

You only need to update the termios baudrate in case you cannot set the
baudrate requested (e.g. > F81232_MAX_BAUDRATE).

> +		f81232_set_baudrate(port, baudrate);
> +	}
> +
> +	if (C_PARENB(tty)) {
> +		new_lcr |= UART_LCR_PARITY;
> +
> +		if (!C_PARODD(tty))
> +			new_lcr |= UART_LCR_EPAR;
> +
> +		if (C_CMSPAR(tty))
> +			new_lcr |= UART_LCR_SPAR;
> +	}
> +
> +	if (C_CSTOPB(tty))
> +		new_lcr |= UART_LCR_STOP;
> +
> +	switch (C_CSIZE(tty)) {
> +	case CS5:
> +		new_lcr |= UART_LCR_WLEN5;
> +		break;
> +	case CS6:
> +		new_lcr |= UART_LCR_WLEN6;
> +		break;
> +	case CS7:
> +		new_lcr |= UART_LCR_WLEN7;
> +		break;
> +	default:
> +	case CS8:
> +		new_lcr |= UART_LCR_WLEN8;
> +		break;
> +	}
> +
> +	status = f81232_set_register(port, LINE_CONTROL_REGISTER, new_lcr);
> +	if (status)
> +		dev_err(&port->dev, "%s failed to set LCR: %d\n",
> +			__func__, status);

Please add brackets around the if block.

> +
>  }
>  
>  static int f81232_tiocmget(struct tty_struct *tty)

Looks good otherwise.

Johan