Re: usbhid: Changes since 2.6.28 in quirk handling?

[Jiri Kosina <jkosina@suse.cz>]

On Fri, 13 Mar 2009, Bill Gribble wrote:

> Hi, I have been maintaining a patch for a quirky USB device built-in to 
> a UMPC, the Raon Digital Everun.  Without the patch, the builtin 
> keyboard, mouse, and touchscreen are useless.  I have never submitted it 
> for inclusion in the kernel because there are less than 5 people who 
> have ever even attempted to install Linux on this device, and it's 
> discontinued.  However, *I* use the thing daily, and its wifi device 
> (libertas) has continued to get better support in the recent kernels so 
> I port the patch forward.

Hi Bill,

we have drivers (and even whole architectures) supported by the kernel, 
which have less than 5 users in the world, that's not a big deal.

It makes 5 people happy, and saves you the pain from having to keep the 
out-of-tree code working with the Linux kernel API changing all the time.

> I noticed that the structure of the quirk handling code has changed 
> somewhat; I left my patch using the "old" way of adding an entry to 
> hid_blacklist in hid-quirks.c.  Is there a document or email trail that 
> describes the new way of structuring this quirk code?  Any pitfalls to 
> look out for?

Looking at your patch, the only thing you need is sending a special URB to 
the device in order to make it operational, right?

Please look at hid-sony driver, which does exactly that for some of the 
PS3 devices.

You then only need to add your device to hid_blacklist[], so that generic 
driver doesn't get bound to it and it'd be driven by your special driver.

-- 
Jiri Kosina
SUSE Labs