On Sun, Sep 30, 2018 at 06:02:24PM +0200, Johan Hovold wrote:
> On Sat, Sep 29, 2018 at 09:54:03AM +0000, YueHaibing wrote:
> > Fixes gcc '-Wunused-but-set-variable' warning:
> >
> > drivers/usb/serial/cypress_m8.c: In function 'cypress_send':
> > drivers/usb/serial/cypress_m8.c:689:33: warning:
> > variable 'actual_size' set but not used [-Wunused-but-set-variable]
> >
> > drivers/usb/serial/cypress_m8.c: In function 'cypress_set_termios':
> > drivers/usb/serial/cypress_m8.c:866:18: warning:
> > variable 'iflag' set but not used [-Wunused-but-set-variable]
> >
> > Signed-off-by: YueHaibing <yuehaib...@huawei.com>
> > ---
> > drivers/usb/serial/cypress_m8.c | 11 ++---------
> > 1 file changed, 2 insertions(+), 9 deletions(-)
> >
> > diff --git a/drivers/usb/serial/cypress_m8.c
> > b/drivers/usb/serial/cypress_m8.c
> > index 31c6091..98dff12 100644
> > --- a/drivers/usb/serial/cypress_m8.c
> > +++ b/drivers/usb/serial/cypress_m8.c
> > @@ -686,7 +686,7 @@ static int cypress_write(struct tty_struct *tty, struct
> > usb_serial_port *port,
> >
> > static void cypress_send(struct usb_serial_port *port)
> > {
> > - int count = 0, result, offset, actual_size;
> > + int count = 0, result, offset;
> > struct cypress_private *priv = usb_get_serial_port_data(port);
> > struct device *dev = &port->dev;
> > unsigned long flags;
> > @@ -758,12 +758,6 @@ static void cypress_send(struct usb_serial_port *port)
> > priv->write_urb_in_use = 1;
> > spin_unlock_irqrestore(&priv->lock, flags);
> >
> > - if (priv->cmd_ctrl)
> > - actual_size = 1;
> > - else
> > - actual_size = count +
> > - (priv->pkt_fmt == packet_format_1 ? 2 : 1);
> > -
>
> This looks like we have a bug in the driver, and sure enough we do.
> Commit 9aa8dae7b1fa ("cypress_m8: use usb_fill_int_urb where
> appropriate") incorrectly started setting the transfer length to the
> size of the buffer.
>
This is like the third time recently where we've had found a real bug.
YueHaibing, could you mention in the commit message where the variable
became unused? It would help reviewing. It's not a Fixes tag but it
would look like this:
"After commit 9aa8dae7b1fa ("cypress_m8: use usb_fill_int_urb where
appropriate") then we don't use actual_size any more so that can
be removed."
regards,
dan carpenter
