Two devices, same USB ID: one needs HID, the other doesn't. How to solve this?
From: Hans Verkuil <hidden>
Date: 2012-01-13 10:42:45
Also in:
linux-media
Hi! I've made a video4linux driver for the USB Keene FM Transmitter. See: http://www.amazon.co.uk/Keene-Electronics-USB-FM-Transmitter/dp/B003GCHPDY/ref=sr_1_1?ie=UTF8&qid=1326450476&sr=8-1 The driver code is here: http://git.linuxtv.org/hverkuil/media_tree.git/shortlog/refs/heads/keene Unfortunately this device has exactly the same USB ID as the Logitech AudioHub USB speaker (http://www.logitech.com/en-us/439/3503). The AudioHub has HID support for volume keys, but the FM transmitter needs a custom V4L2 driver instead. I've attached the full lsusb -v output of both devices, but this is the diff of the two: $ diff keene.txt audiohub.txt -u
--- keene.txt 2012-01-13 11:10:48.265399953 +0100
+++ audiohub.txt 2012-01-13 11:09:45.185398935 +0100@@ -1,5 +1,5 @@ -Bus 007 Device 009: ID 046d:0a0e Logitech, Inc. +Bus 003 Device 004: ID 046d:0a0e Logitech, Inc. Device Descriptor: bLength 18 bDescriptorType 1
@@ -12,7 +12,7 @@ idProduct 0x0a0e bcdDevice 1.00 iManufacturer 1 HOLTEK - iProduct 2 B-LINK USB Audio + iProduct 2 AudioHub Speaker iSerial 0 bNumConfigurations 1 Configuration Descriptor:
@@ -22,9 +22,8 @@ bNumInterfaces 3 bConfigurationValue 1 iConfiguration 0 - bmAttributes 0xa0 + bmAttributes 0x80 (Bus Powered) - Remote Wakeup MaxPower 500mA Interface Descriptor: bLength 9
@@ -152,7 +151,7 @@ bCountryCode 0 Not supported bNumDescriptors 1 bDescriptorType 34 Report - wDescriptorLength 22 + wDescriptorLength 31 Report Descriptors: ** UNAVAILABLE ** Endpoint Descriptor:
As you can see, the differences are very small. In my git tree I worked around it by adding the USB ID to the ignore list if the Keene driver is enabled, and ensuring that the Keene driver is disabled by default. But is there a better method to do this? At least the iProduct strings are different, is that something that can be tested in hid-core.c? Regards, Hans
Attachments
- audiohub.txt [text/plain] 5905 bytes · preview
- keene.txt [text/plain] 5927 bytes · preview