Re: "permanently" unbind a device from a driver?

From: Sam Liddicott
Date: Wed Jan 21 2009 - 12:52:52 EST


* Greg KH wrote, On 21/01/09 16:23:
> On Wed, Jan 21, 2009 at 11:44:03PM +0800, Ming Lei wrote:
>
>> 2009/1/21 Greg KH <greg@xxxxxxxxx>:
>>
>>> Just add a blacklist rule to the usbhid driver for this device. There
>>> are a number of devices out there that need this functionality, which is
>>> why there is such a list.
>>>
>> Is it possible to implement a generic blacklist mechanism in driver core
>> to support the function for all kinds of drivers? or is it necessary to do that?
>>
>
> It's not necessary as the hid core already supports this very thing due
> to the need for it (it's the easiest way to write a userspace Windows
> driver, so lots of manufacturers lie about their devices in order to
> work around having to write a Windows kernel driver.)
>
> So just add this device to the hid core blacklist, and you are all set.
>
> Care to send a patch?
>

I've often felt that a /proc or /sys interface to allow blacklist
additions or quirk addition would be great.

Hacking of new devices often runs faster than distro's kernel releases;
it will often be very simple to distribute a 1 liner to make some
hardware available than tell people to wait until the next major release
of their distro.

As a point in instance, a couple of years ago I gave up trying to get
some quirks added for usb dual and quad joystick adaptors. I got them
added for one of them but not the other. It was just too much hard work.

I will say for the record that you, Greg, were very helpful, but all
told it was a couple of hours to build and test each quirk patch (I
didn't get the controllers at the same time), and then knowing that I
would either have to maintain my own out-of-distro kernel or wait about
18 months for my distro to get the patch - meant that the work was not
solving any immediate problem; so the pay-off in relation to the
scarcity of my time meant it just got forgotten.

An user-space post-boot uploadable quirk/blacklist would be great and
IMHO result in a bigger supply of quirks.

Sam
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