Possibly Japan-exclusive MELCO (Buffalo) WLI-UV-AG300 WiFi USB adapter with AR9280+AR7010 chipset. Says WLI-UV-AG300P on the package, but WLI-UV-AG300 on the adapter itself. Only needed the vendor and device IDs added to work. Ok?

diff /usr/src
path + /usr/src
commit - 0120f5b67b1edd3eeacc2e18c0a21209b21a3c10
blob - 0eed5ca2a34603039cad0f8d196dbd960dcaa2b2
file + sys/dev/usb/if_athn_usb.c
--- sys/dev/usb/if_athn_usb.c
+++ sys/dev/usb/if_athn_usb.c
@@ -87,6 +87,8 @@ static const struct athn_usb_type {
 	   ATHN_USB_FLAG_AR7010 },
 	{{ USB_VENDOR_PANASONIC, USB_PRODUCT_PANASONIC_N5HBZ0000055 },
 	   ATHN_USB_FLAG_AR7010 },
+	{{ USB_VENDOR_MELCO, USB_PRODUCT_MELCO_WLIUVAG300 },
+	   ATHN_USB_FLAG_AR7010 },
 	{{ USB_VENDOR_MELCO, USB_PRODUCT_MELCO_UWABR100 },
 	   ATHN_USB_FLAG_AR7010 },
 	{{ USB_VENDOR_VIA, USB_PRODUCT_VIA_AR9271 }}
commit - 0120f5b67b1edd3eeacc2e18c0a21209b21a3c10
blob - c9e442e992f614de2700be64df9f2a54075666e8
file + sys/dev/usb/usbdevs.h
--- sys/dev/usb/usbdevs.h
+++ sys/dev/usb/usbdevs.h
@@ -3164,6 +3164,7 @@
 #define	USB_PRODUCT_MELCO_WLIUCGN	0x015d		/* WLI-UC-GN */
 #define	USB_PRODUCT_MELCO_WLIUCG301N	0x016f		/* WLI-UC-G301N */
 #define	USB_PRODUCT_MELCO_UWABR100	0x017f		/* SONY UWA-BR100 */
+#define	USB_PRODUCT_MELCO_WLIUVAG300	0x0197		/* WLI-UV-AG300 */
 #define	USB_PRODUCT_MELCO_WLIUCGNM	0x01a2		/* WLI-UC-GNM */
 #define	USB_PRODUCT_MELCO_WLIUCGNM2	0x01ee		/* WLI-UC-GNM2 */