Re: [PATCH] USB: serial: option: add support for D-Link DWM-157 C1

[Johan Hovold]

On Mon, Aug 28, 2017 at 04:32:53PM +0200, Maciej S. Szmigiero wrote:
> Hi Johan,
> 
> On 28.08.2017 12:19, Johan Hovold wrote:
> > On Mon, Aug 21, 2017 at 05:43:46PM +0200, Maciej S. Szmigiero wrote:
> >> This commit adds support (IDs, really) for D-Link DWM-157 hardware version
> >> C1 USB modem to option driver.
> >>
> >> According to manufacturer-provided Windows INF file the device has four
> >> serial ports:
> >> "D-Link HSPA+DataCard Diagnostics Interface" (interface 2; modem port),
> >> "D-Link HSPA+DataCard NMEA Device" (interface 3),
> >> "D-Link HSPA+DataCard Speech Port" (interface 4),
> >> "D-Link HSPA+DataCard Debug Port" (interface 5).
> >>
> >> Signed-off-by: Maciej S. Szmigiero <mail@xxxxxxxxxxxxxxxxxxxxx>
> >> Cc: stable@xxxxxxxxxxxxxxx
> >> ---
> >>  drivers/usb/serial/option.c | 2 ++
> >>  1 file changed, 2 insertions(+)
> >>
> >> diff --git a/drivers/usb/serial/option.c b/drivers/usb/serial/option.c
> >> index fe123153b1a5..fa887c6e50e7 100644
> >> --- a/drivers/usb/serial/option.c
> >> +++ b/drivers/usb/serial/option.c
> >> @@ -2023,6 +2023,8 @@ static const struct usb_device_id option_ids[] = {
> >>  	{ USB_DEVICE_AND_INTERFACE_INFO(0x2001, 0x7d03, 0xff, 0x02, 0x01) },
> >>  	{ USB_DEVICE_AND_INTERFACE_INFO(0x2001, 0x7d03, 0xff, 0x00, 0x00) },
> >>  	{ USB_DEVICE_INTERFACE_CLASS(0x2001, 0x7d04, 0xff) },			/* D-Link DWM-158 */
> >> +	{ USB_DEVICE_AND_INTERFACE_INFO(0x2001, 0x7d0e, 0xff, 0x02, 0x01) },    /* D-Link DWM-157 C1 */
> >> +	{ USB_DEVICE_AND_INTERFACE_INFO(0x2001, 0x7d0e, 0xff, 0x00, 0x00) },
> > 
> > What is the reason for not using a single USB_DEVICE_INTERFACE_CLASS
> > here instead?
> 
> This is done to be as specific as possible (in case D-Link makes a
> similar device with a different interface list or changes it
> with a firmware update).

We can always add more specific matching if this ever becomes an issue.

> Also, three other D-Link modems few lines above are using the same
> USB_DEVICE_AND_INTERFACE_INFO() selectors.

Yeah, I noticed those, and I'm not sure why they're not using
class-matching only either (and note that we have some entries that do).

> > Do you have access to this device so that you could post the output of
> > usb-devices (or "lsusb -v")? 
> 
> I've attached lsusb output to this message, since it is pretty long.

Ok, thanks. So using USB_DEVICE_INTERFACE_CLASS() looks like it would
work for this device, so please use that instead.

If possible, try to include the more compact output of usb-devices in
the commit message so we have it easily accessible.

Thanks,
Johan