Re: Linux Force Feedback for Saitek Cyborg Evo Force

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Sun, Dec 20, 2009 at 12:36:23AM +0100, Johannes Ebke wrote:
> Hi,
> 
> It seems that the force feedback works well, I have ported the force
> feedback for my favorite game to linux now, and it works well.
> 
> What does not work is updating effects - there just nothing happens, and
> the old event is played. I have circumvented this by
> deleting/re-uploading the effect, but this should probably been made to
> work. Does it work well with other hardware?
> 
> Thirdly, I have re-discovered one kernel oops that occurs if the
> joystick is unplugged if some process still has the event device open.
> Steps to reproduce:
> * plug joystick in
> * fftest /dev/input/eventXX
> * unplug joystick
> 
> (kern.log extract attached)
> 
> Sometimes this just gives an oops, sometimes it escalates into a kernel
> panic.
> 

Hmm, it looks like iforce unbinding is completely busted:

static void iforce_usb_disconnect(struct usb_interface *intf)
{
        struct iforce *iforce = usb_get_intfdata(intf);
        int open = 0; /* FIXME! iforce->dev.handle->open; */
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

        usb_set_intfdata(intf, NULL);
        if (iforce) {
                iforce->usbdev = NULL;
                input_unregister_device(iforce->dev);

                if (!open) {
                        iforce_delete_device(iforce);
                        kfree(iforce);
                }
        }
}


Any chance you could fix that FIXME ;) ?

-- 
Dmitry