[PATCH] 8250_pci: Prevent Exar/RTD Boards from binding.

[greg@kroah.com (Greg KH)]

On Fri, Sep 25, 2015 at 11:46:29AM -0400, Rob Groner wrote:
> Serial boards made by RTD using the Exar XR17V358 chip
> rely on the extra capabilities of the Exar-provided driver
> to allow configuration of the board.  When support for
> the Exar chip was added to the kernel 8250_pci driver, this
> then prevented easy use of the board by customers for anything
> other than standard serial usage in RS232 mode.
> 
> This patch prevents RTD sub-vendor boards from being bound
> by the 8250_pci driver, if it uses the XR17V358 chip.  Other
> RTD boards using Exar chips are not affected.
> 
> Signed-off-by Rob Groner <rgroner@rtd.com>
> ---
>  drivers/tty/serial/8250/8250_pci.c | 20 ++++++++++++++++++++
>  1 file changed, 20 insertions(+)
> 
> diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
> index 68042dd..89baf7f 100644
> --- a/drivers/tty/serial/8250/8250_pci.c
> +++ b/drivers/tty/serial/8250/8250_pci.c
> @@ -359,6 +359,16 @@ static void pci_ni8430_exit(struct pci_dev *dev)
>  	iounmap(p);
>  }
>  
> +/*
> + * RTD Embedded Technologies, Inc. boards
> + * Prevent from being bound to 8250 driver
> + */
> +static int
> +pci_xr17v35x_rtd_probe(struct pci_dev *dev)
> +{
> +	return -ENODEV;
> +}
> +
>  /* SBS Technologies Inc. PMC-OCTPRO and P-OCTAL cards */
>  static int
>  sbs_setup(struct serial_private *priv, const struct pciserial_board *board,
> @@ -2105,6 +2115,8 @@ pci_wch_ch38x_setup(struct serial_private *priv,
>  #define PCI_DEVICE_ID_PERICOM_PI7C9X7954	0x7954
>  #define PCI_DEVICE_ID_PERICOM_PI7C9X7958	0x7958
>  
> +#define PCI_SUBVENDOR_ID_RTD		0x1435
> +
>  /* Unknown vendors/cards - this should not be in linux/pci_ids.h */
>  #define PCI_SUBDEVICE_ID_UNKNOWN_0x1584	0x1584
>  #define PCI_SUBDEVICE_ID_UNKNOWN_0x1588	0x1588
> @@ -2608,6 +2620,14 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = {
>  	{
>  		.vendor = PCI_VENDOR_ID_EXAR,
>  		.device = PCI_DEVICE_ID_EXAR_XR17V358,
> +		.subvendor = PCI_SUBVENDOR_ID_RTD,
> +		.subdevice	= PCI_ANY_ID,
> +		.probe		= pci_xr17v35x_rtd_probe,
> +		.setup		= pci_xr17v35x_setup,

Why do you need the .setup callback if you are just not wanting to bind
to this driver?

thanks,

greg k-h