On Tue, Feb 28, 2017 at 12:51:25PM +0000, Ian Abbott wrote: > Valid latency timer values are between 1 ms and 255 ms in 1 ms steps. > The store function for the "latency_timer" device attribute currently > allows any value, although only the lower 8-bits will be written to the > latency timer. Return an error for out-of-range values. And in fact, 0 is currently used (and accepted by the device) if a negative value is provided. > Signed-off-by: Ian Abbott <abbotti@xxxxxxxxx> > --- > drivers/usb/serial/ftdi_sio.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c > index a1b90f4184a7..2da99875cecb 100644 > --- a/drivers/usb/serial/ftdi_sio.c > +++ b/drivers/usb/serial/ftdi_sio.c > @@ -1716,6 +1716,9 @@ static ssize_t latency_timer_store(struct device *dev, > int v = simple_strtoul(valbuf, NULL, 10); > int rv; > > + if (v < 1 || v > 255) > + return -EINVAL; > + We probably still need to accept 0 here, which seems to give a timer of 1 ms, as someone may be relying on that behaviour already. > priv->latency = v; > rv = write_latency_timer(port); > if (rv < 0) Johan -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html