Re: 2.6.36/2.6.37: broken compatibility with userspace input-utils ?

[Dmitry Torokhov]

On Mon, Jan 24, 2011 at 09:31:17PM -0800, Dmitry Torokhov wrote:
> On Tue, Jan 25, 2011 at 12:07:29AM -0500, Mark Lord wrote:
> > On 11-01-25 12:04 AM, Mark Lord wrote:
> > > On 11-01-24 11:55 PM, Dmitry Torokhov wrote:
> > >> On Mon, Jan 24, 2011 at 11:37:06PM -0500, Mark Lord wrote:
> > > ..
> > >>> This results in (map->size==10) for 2.6.36+ (wrong),
> > >>> and a much larger map->size for 2.6.35 and earlier.
> > >>>
> > >>> So perhaps EVIOCGKEYCODE has changed?
> > >>>
> > >>
> > >> So the utility expects that all devices have flat scancode space and
> > >> driver might have changed so it does not recognize scancode 10 as valid
> > >> scancode anymore.
> > >>
> > >> The options are:
> > >>
> > >> 1. Convert to EVIOCGKEYCODE2
> > >> 2. Ignore errors from EVIOCGKEYCODE and go through all 65536 iterations.
> > > 
> > > or 3. Revert/fix the in-kernel regression.
> > > 
> > > The EVIOCGKEYCODE ioctl is supposed to return KEY_RESERVED for unmapped
> > > (but value) keycodes, and only return -EINVAL when the keycode itself
> > > is out of range.
> > > 
> > > That's how it worked in all kernels prior to 2.6.36,
> > > and now it is broken.  It now returns -EINVAL for any unmapped keycode,
> > > even though keycodes higher than that still have mappings.
> > > 
> > > This is a bug, a regression, and breaks userspace.
> > > I haven't identified *where* in the kernel the breakage happened,
> > > though.. that code confuses me.  :)
> > 
> > Note that this device DOES have "flat scancode space",
> > and the kernel is now incorrectly signalling an error (-EINVAL)
> > in response to a perfectly valid query of a VALID (and mappable)
> > keycode on the remote control
> > 
> > The code really is a valid button, it just doesn't have a default mapping
> > set by the kernel (I can set a mapping for that code from userspace and it works).
> > 
> 
> OK, in this case let's ping Mauro - I think he done the adjustments to
> IR keymap hanlding.
> 
> Thanks.
> 

BTW, could you please try the following patch (it assumes that
EVIOCGVERSION in input.c is alreday relaxed).

Thanks!

-- 
Dmitry