[Libdlo] [ANNOUNCE] displaylink-mod-0.3(alpha) (was udlfb)

[Roberto De Ioris]

On Thu, 2009-07-09 at 09:00 -0600, jasonlife wrote:
> 
> On Thu, Jul 9, 2009 at 3:51 AM, Roberto De Ioris <roberto at unbit.it>
> wrote:
>         On Wed, 2009-07-08 at 11:36 -0600, jasonlife wrote:
>         > Attached is the dmesg from my laptop.
>         
>         
>         
>         
>         The only way i found to reproduce this errors is set an
>         alternative usb
>         configuration (for example the hp docking station has 2
>         configuration,
>         one for HID mode and the other for DisplayLink).
> 
> Could you explain little bit more about this problem?  I noticed my
> Samsung monitor provides a HID interface as you expected.  Does a
> DisplayLink USB device have a problem if it also provides other device
> types like keyboard/mouse (HID) and sound?     
>  



USB devices can have multiple configuration (even if it is not used
often).

Your monitor (as my HP docking station) as 2 configuration, one put the
device in HID mode, the other one in DisplayLink mode.

I do not know why hp and samsung has made this decision, but on linux is
a pain in the ass setting a configuration for usb devices as the host
controller driver get the most useful one using an (IMHO totally wrong)
algorithm.

The only (raw) solution i found is to unload the usbhid module, then set
the first configuration for the usb device using /sys (look for the file
bConfigurationValue, it must contain '1' and not '2') and then reload
the displaylink module.

I must admit that i have no experience on multiple configuration usb
device, so probably someone could point me to a real solution.

>         
>         
> 


-- 
Roberto De Ioris
http://unbit.it
JID: roberto at jabber.unbit.it