Re: [PATCH v3 06/13] USB: ch341: add support for parity, frame length, stop bits

[Grigori Goronzy]

On 2016-04-11 19:25, Karl Palsson wrote:
> Sorry if you get this twice, I was having some client problems,
> but wanted to make sure you got this one...
>
>
> Grigori Goronzy <greg@xxxxxxxxxxxx> wrote:
> > With the new reinitialization method, configuring parity,
> > different frame lengths and different stop bit settings work as
> > expected on both CH340G and CH341A. This has been extensively
> > tested with a logic analyzer.
> >
> > v2: only set mark/space when parity is enabled,
> > simplifications, patch termios HW flags.
> >
> > Tested-by: Ryan Barber <rfb@xxxxxxxxxxxxx>
> > Signed-off-by: Grigori Goronzy <greg@xxxxxxxxxxxx>
> > ---
> >  drivers/usb/serial/ch341.c | 40 
> > ++++++++++++++++++++++++++++++----------
> >  1 file changed, 30 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/usb/serial/ch341.c
> > b/drivers/usb/serial/ch341.c index 6181616..99b4621 100644
> > --- a/drivers/usb/serial/ch341.c
> > +++ b/drivers/usb/serial/ch341.c
> > @@ -341,7 +341,6 @@ static void ch341_set_termios(struct tty_struct 
> > *tty,
> >  		struct usb_serial_port *port, struct ktermios *old_termios)
> >  {
> >  	struct ch341_private *priv = usb_get_serial_port_data(port);
> > -	unsigned baud_rate;
> >  	unsigned long flags;
> >  	unsigned char ctrl;
> >  	int r;
> > @@ -350,13 +349,39 @@ static void ch341_set_termios(struct tty_struct 
> > *tty,
> >  	if (old_termios && !tty_termios_hw_change(&tty->termios, 
> > old_termios))
> >  		return;
> >
> > -	baud_rate = tty_get_baud_rate(tty);
> > +	priv->baud_rate = tty_get_baud_rate(tty);
> >
> > -	priv->baud_rate = baud_rate;
> > +	ctrl = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX;
> >
> > -	ctrl = CH341_LCR_ENABLE_RX | CH341_LCR_ENABLE_TX | CH341_LCR_CS8;
> > +	switch (C_CSIZE(tty)) {
> > +	case CS5:
> > +		ctrl |= CH341_LCR_CS5;
> > +		break;
> > +	case CS6:
> > +		ctrl |= CH341_LCR_CS6;
> > +		break;
> > +	case CS7:
> > +		ctrl |= CH341_LCR_CS7;
> > +		break;
> > +	default:
> > +		tty->termios.c_cflag |= CS8;
> > +	case CS8:
> > +		ctrl |= CH341_LCR_CS8;
> > +		break;
> > +	}
> > +
> > +	if (C_PARENB(tty)) {
> > +		ctrl |= CH341_LCR_ENABLE_PAR;
> > +		if (C_PARODD(tty))
> > +			ctrl |= CH341_LCR_PAR_EVEN;
>
> Are you sure this does the right thing now? this is, as best as I
> can tell, the inverse of what you had earlier, and doesn't read
> right, if this is working, then I suggest renaming _LCR_PAR_EVEN
> to LCR_PAR_ODD?

No, this is absolutely wrong, of course.  I only did some sporadic 
testing because my refactoring wasn't supposed to change functionality.  
Thanks for pointing it out!

Grigori