Re: [PATCH 1/3] tty/serial_core: add ISO7816 infrastructure

From: Ludovic Desroches
Date: Fri Jul 13 2018 - 04:02:43 EST


On Thu, Jul 12, 2018 at 04:58:08PM +0200, Greg KH wrote:
> On Wed, Jul 11, 2018 at 03:16:36PM +0200, Ludovic Desroches wrote:
> > From: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
> >
> > Add the ISO7816 ioctl and associated accessors and data structure.
> > Drivers can then use this common implementation to handle ISO7816.
> >
> > Signed-off-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
> > [ludovic.desroches@xxxxxxxxxxxxx: squash and rebase, removal of gpios, checkpatch fixes]
> > Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxxxxxx>
> > ---
> > drivers/tty/serial/serial_core.c | 49 +++++++++++++++++++++++++++++++++++++++
> > include/linux/serial_core.h | 3 +++
> > include/uapi/asm-generic/ioctls.h | 2 ++
> > include/uapi/linux/serial.h | 17 ++++++++++++++
> > 4 files changed, 71 insertions(+)
>
> Note, kbuild found build issues with this, please fix up.
>
> Also, here's some comments:
>
> >
> > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> > index 9c14a453f73c..c89ac59f6f8c 100644
> > --- a/drivers/tty/serial/serial_core.c
> > +++ b/drivers/tty/serial/serial_core.c
> > @@ -1301,6 +1301,47 @@ static int uart_set_rs485_config(struct uart_port *port,
> > return 0;
> > }
> >
> > +static int uart_get_iso7816_config(struct uart_port *port,
> > + struct serial_iso7816 __user *iso7816)
> > +{
> > + unsigned long flags;
> > + struct serial_iso7816 aux;
> > +
> > + spin_lock_irqsave(&port->lock, flags);
> > + aux = port->iso7816;
>
> Don't you want to check to see if there is a function for iso7816 before
> copying it? Otherwise it's just empty, right?

I'll add the check.

>
> > + if (!port->iso7816_config)
> > + return -ENOIOCTLCMD;
>
> Why this error value?
>

It was a mimic of RS485.

> > --- a/include/uapi/asm-generic/ioctls.h
> > +++ b/include/uapi/asm-generic/ioctls.h
> > @@ -66,6 +66,8 @@
> > #ifndef TIOCSRS485
> > #define TIOCSRS485 0x542F
> > #endif
> > +#define TIOCGISO7816 0x5430
> > +#define TIOCSISO7816 0x5431
>
> Where did you get these numbers from?

I will use the macros to create numbers. Any rules about nr choice?

Regards

Ludovic

>
> thanks,
>
> greg k-h