lkml.org 
[lkml]   [2010]   [Dec]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [RFC] Input: define separate EVIOCGKEYCODE_V2/EVIOCSKEYCODE_V2
    On Thu, Dec 09, 2010 at 11:16:47AM -0800, Dmitry Torokhov wrote:
    > On Thu, Dec 09, 2010 at 08:04:36PM +0100, Henrik Rydberg wrote:
    > > On 12/09/2010 10:39 AM, Dmitry Torokhov wrote:
    > >
    > > > The desire to keep old names for the EVIOCGKEYCODE/EVIOCSKEYCODE while
    > > > extending them to support large scancodes was a mistake. While we tried
    > > > to keep ABI intact (and we succeeded in doing that, programs compiled
    > > > on older kernels will work on newer ones) there is still a problem with
    > > > recompiling existing software with newer kernel headers.
    > > >
    > > > New kernel headers will supply updated ioctl numbers and kernel will
    > > > expect that userspace will use struct input_keymap_entry to set and
    > > > retrieve keymap data. But since the names of ioctls are still the same
    > > > userspace will happily compile even if not adjusted to make use of the
    > > > new structure and will start miraculously fail in the field.
    > > >
    > > > To avoid this issue let's revert EVIOCGKEYCODE/EVIOCSKEYCODE definitions
    > > > and add EVIOCGKEYCODE_V2/EVIOCSKEYCODE_V2 so that userspace can explicitly
    > > > select the style of ioctls it wants to employ.
    > > >
    > > > Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
    > > > ---
    > >
    > >
    > > Would the header change suffice in itself?
    >
    > We still need to change evdev to return -EINVAL on wrong sizes but yes,
    > the amount of change there could be more limited. I just thought that
    > splitting it up explicitly shows the differences in handling better. If
    > people prefer the previos version we could leave it, I am 50/50 between
    > them.
    >

    *ping*

    Mauro, Jarod, do you have an opinion on this? I think we need to settle
    on a solution before 2.6.37 is out.

    Thanks.

    --
    Dmitry


    \
     
     \ /
      Last update: 2010-12-13 10:09    [W:0.022 / U:0.032 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site