lkml.org 
[lkml]   [2006]   [Jul]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: Implement class_device_update_dev() function
    From
    Date
    On Fri, 2006-07-07 at 09:42 +0200, Marcel Holtmann wrote:
    > Hi Greg,
    >
    > > > for the Bluetooth subsystem integration into the driver model it is
    > > > required that we can update the device of a class device at any time.
    > >
    > > You can? Ick.
    > >
    > > That messes with my "get rid of struct class_device" plans a bit...
    >
    > this must not be a class device, but at the moment TTY, network and
    > input are still class devices. The Bluetooth subsystem moved away from
    > using class devices.
    >
    > > > For the RFCOMM TTY device for example we create the TTY device and only
    > > > when it got opened we create the Bluetooth connection. Once this new
    > > > connection has been created we have a device to attach to the class
    > > > device of the TTY.
    > > >
    > > > I came up with the attached patch and it worked fine with the Bluetooth
    > > > RFCOMM layer.
    > >
    > > But userspace should also find out about this change, and this patch
    > > prevents that from happening. What about just tearing down the class
    > > device and creating a new one? That way userspace knows about the new
    > > linkage properly, and any device naming and permission issues can be
    > > handled anew?
    >
    > This won't work for Bluetooth. We create the TTY and its class device
    > with tty_register_device() and then the device node is present. Then at
    > some point later we open that device and the Bluetooth connection gets
    > established. Only when the connection has been established we know the
    > device that represents it. So tearing down the class device and creating
    > a new one will screw up the application that is using this device node.
    >
    > Would reissuing the uevent of the class device help here?

    How about KOBJ_ONLINE/OFFLINE?

    Thanks,
    Kay

    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2006-07-08 02:29    [W:5.509 / U:0.000 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site